00377nas a2200097   4500008004100000245005300041210005100094260001200145100002100157856010100178       2018                        eng d00a7th Operant Conditioning Meeting, Charleston, SC0 a7th Operant Conditioning Meeting Charleston SC  c03/20181 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2018/7th-operant-conditioning-meeting-charleston-sc02226nas a2200145   4500008004100000022001400041245007400055210006900129300001400198490000700212520174700219100002201966700002101988856007102009       2018                        eng d  a2352-154600aAcquisition, maintenance, and therapeutic use of a simple motor skill0 aAcquisition maintenance and therapeutic use of a simple motor sk  a138 - 1440 v203 aOperant conditioning of the spinal stretch reflex (SSR) or its electrical analog, the H-reflex, is a valuable experimental paradigm for studying the acquisition and maintenance of a simple motor skill. The central nervous system (CNS) substrate of this skill consists of brain and spinal cord plasticity that operates as a hierarchy—the learning experience induces plasticity in the brain that guides and maintains plasticity in the spinal cord. This is apparent in the two components of the skill acquisition: task-dependent adaptation, reflecting brain plasticity; and long-term change, reflecting gradual development of spinal plasticity. The inferior olive, cerebellum, sensorimotor cortex, and corticospinal tract (CST) are essential components of this hierarchy. The neuronal and synaptic mechanisms of the spinal plasticity are under study. Because acquisition of this skill changes the spinal cord, it can affect other skills, such as locomotion. Thus, it enables investigation of how the highly plastic spinal cord supports the acquisition and maintenance of a broad repertoire of motor skills throughout life. These studies have resulted in the negotiated equilibrium model of spinal cord function, which reconciles the spinal cord's long-recognized reliability as the final common pathway for behaviors with its recently recognized ongoing plasticity. In accord with this model, appropriate H-reflex conditioning in a person with spasticity due to an incomplete spinal cord injury can trigger wider beneficial plasticity that markedly improves walking. H-reflex operant conditioning appears to provide a valuable new method for enhancing functional recovery in people with spinal cord injury and possibly other disorders as well.1 aNorton, James, JS1 aWolpaw, Jonathan  uhttp://www.sciencedirect.com/science/article/pii/S235215461730219X00451nas a2200109   4500008004100000245006000041210005900101260001200160520004200172100002100214856010600235       2018                        eng d00aBrain-Computer Interfaces For Communication And Control0 aBrainComputer Interfaces For Communication And Control  c08/20183 aNANS Summer Series, New York City, NY1 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2018/brain-computer-interfaces-communication-and-control00652nas a2200157   4500008004100000245015700041210006900198260001200267100001700279700001300296700001300309700001300322700001300335700002100348856012500369       2018                        eng d00aCombining H-reflex conditioning and locomotor training appears to enhance locomotor recovery in rats with incomplete spinal cord injury: Initial results0 aCombining Hreflex conditioning and locomotor training appears to  c11/20181 aChen, X., Y.1 aChen, L.1 aYang, X.1 aWang, Y.1 aChen, Y.1 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2018/combining-h-reflex-conditioning-and-locomotor-training-appears-enhance02706nas a2200265   4500008004100000245009100041210006900132260001200201490000700213520195600220653000802176653001802184653001902202653001002221653002402231653001102255100001502266700001802281700001302299700001502312700001802327700002102345700002202366856005202388       2018                        eng d00aControlling pre-movement sensorimotor rhythm can improve finger extension after stroke0 aControlling premovement sensorimotor rhythm can improve finger e  c08/20180 v153 aObjective. Brain–computer interface (BCI) technology is attracting increasing interest as a tool for enhancing recovery of motor function after stroke, yet the optimal way to apply this technology is unknown. Here, we studied the immediate and therapeutic effects of BCI-based training to control pre-movement sensorimotor rhythm (SMR) amplitude on robot-assisted finger extension in people with stroke. Approach. Eight people with moderate to severe hand impairment due to chronic stroke completed a four-week three-phase protocol during which they practiced finger extension with assistance from the FINGER robotic exoskeleton. In Phase 1, we identified spatiospectral SMR features for each person that correlated with the intent to extend the index and/or middle finger(s). In Phase 2, the participants learned to increase or decrease SMR features given visual feedback, without movement. In Phase 3, the participants were cued to increase or decrease their SMR features, and when successful, were then cued to immediately attempt to extend the finger(s) with robot assistance. Main results. Of the four participants that achieved SMR control in Phase 2, three initiated finger extensions with a reduced reaction time after decreasing (versus increasing) pre-movement SMR amplitude during Phase 3. Two also extended at least one of their fingers more forcefully after decreasing pre-movement SMR amplitude. Hand function, measured by the box and block test (BBT), improved by 7.3  ±  7.5 blocks versus 3.5  ±  3.1 blocks in those with and without SMR control, respectively. Higher BBT scores at baseline correlated with a larger change in BBT score. Significance. These results suggest that learning to control person-specific pre-movement SMR features associated with finger extension can improve finger extension ability after stroke for some individuals. These results merit further investigation in a rehabilitation context.10aBCI10aMotor control10aRehabilitation10arobot10asensorimotor rhythm10aStroke1 aNorman, SL1 aMcFarland, DJ1 aMiner, A1 aCramer, SC1 aWolbrecht, ET1 aWolpaw, Jonathan1 aReinkensmeyer, DJ  uhttp://stacks.iop.org/1741-2552/15/i=5/a=05602600754nas a2200181   4500008004100000245016600041210006900207260002700276100001800303700001400321700001500335700001900350700001900369700002000388700002000408700002100428856012300449       2018                        eng d00aCreating an eyes-closed binary SSVEP-based brain-computer interface (BCI) for the bedside: A comparison of foveal centered and off-centered stimulus presentation0 aCreating an eyesclosed binary SSVEPbased braincomputer interface  aSan Diego, CAc11/20181 aVaughan, T.M.1 aAslam, M.1 aZoltan, B.1 aBrunner, Peter1 aNorton, J., J.1 aCarmack, C., S.1 aZeitlin, D., J.1 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2018/creating-eyes-closed-binary-ssvep-based-brain-computer-interface-bci00743nas a2200181   4500008004100000245016600041210006900207260001200276100002000288700001400308700001500322700001900337700001900356700002000375700002000395700002100415856012500436       2018                        eng d00aCreating an eyes-closed binary SSVEP-based brain-computer interface (BCI) for the bedside: A comparison of foveal centered and off-centered stimulus presentation0 aCreating an eyesclosed binary SSVEPbased braincomputer interface  c11/20181 aVaughan, T., M.1 aAslam, M.1 aZoltan, B.1 aBrunner, Peter1 aNorton, J., J.1 aCarmack, C., S.1 aZeitlin, D., J.1 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2018/creating-eyes-closed-binary-ssvep-based-brain-computer-interface-bci-000430nas a2200097   4500008004100000245007300041210006900114260001200183100002100195856011600216       2018                        eng d00aDepartment of Kinesiology, Penn State University, State College, PA.0 aDepartment of Kinesiology Penn State University State College PA  c10/20181 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2018/department-kinesiology-penn-state-university-state-college-pa02519nas a2200277   4500008004100000022001400041245009000055210006900145260001200214490000700226520169200233653003401925653001801959653001301977653002501990653003002015100001702045700001502062700001502077700001302092700001702105700001502122700002102137700001802158856006502176       2018                        eng d  a1662-453X00aEffects of Sensorimotor Rhythm Modulation on the Human Flexor Carpi Radialis H-Reflex0 aEffects of Sensorimotor Rhythm Modulation on the Human Flexor Ca  c07/20180 v123 aPeople can learn over training sessions to increase or decrease sensorimotor rhythms (SMRs) in the electroencephalogram (EEG). Activity-dependent brain plasticity is thought to guide spinal plasticity during motor skill learning; thus, SMR training may affect spinal reflexes and thereby influence motor control. To test this hypothesis, we investigated the effects of learned mu (8–13 Hz) SMR modulation on the flexor carpi radialis (FCR) H-reflex in 6 subjects with no known neurological conditions and 2 subjects with chronic incomplete spinal cord injury (SCI). All subjects had learned and practiced over more than 10 < 30-min training sessions to increase (SMR-up trials) and decrease (SMR-down trials) mu-rhythm amplitude over the hand/arm area of left sensorimotor cortex with ≥80% accuracy. Right FCR H-reflexes were elicited at random times during SMR-up and SMR-down trials, and in between trials. SMR modulation affected H-reflex size. In all the neurologically normal subjects, the H-reflex was significantly larger [116% ± 6 (mean ± SE)] during SMR-up trials than between trials, and significantly smaller (92% ± 1) during SMR-down trials than between trials (p < 0.05 for both, paired t-test). One subject with SCI showed similar H-reflex size dependence (high for SMR-up trials, low for SMR-down trials): the other subject with SCI showed no dependence. These results support the hypothesis that SMR modulation has predictable effects on spinal reflex excitability in people who are neurologically normal; they also suggest that it might be used to enhance therapies that seek to improve functional recovery in some individuals with SCI or other CNS disorders.

10abrain-computer interface (BC)10aEEG mu-rhythm10aH-Reflex10aSpinal Cord Injuries10atask-dependent adaptation1 aThompson, AK1 aCarruth, H1 aHaywood, R1 aHill, NJ1 aSarnacki, WA1 aMcCane, LM1 aWolpaw, Jonathan1 aMcFarland, DJ  uhttps://www.frontiersin.org/article/10.3389/fnins.2018.0050502689nas a2200397   4500008004100000022001400041245010000055210006900155260001200224520157100236653003301807653003001840653002201870653001101892100002101903700001601924700001301940700001501953700001401968700001601982700001601998700001602014700001602030700001402046700001802060700001602078700001102094700001302105700001602118700001102134700001402145700001302159700001402172700001302186856009202199       2018                        eng d  a1526-632X00aIndependent home use of a brain-computer interface by people with amyotrophic lateral sclerosis0 aIndependent home use of a braincomputer interface by people with  c06/20183 aObjective: To assess the reliability and usefulness of an EEG-based brain-computer interface (BCI) for patients with advanced amyotrophic lateral sclerosis (ALS) who used it independently at home for up to 18 months.

Methods: Of 42 patients consented, 39 (93%) met the study criteria, and 37 (88%) were assessed for use of the Wadsworth BCI. Nine (21%) could not use the BCI. Of the other 28, 27 (men, age 28–79 years) (64%) had the BCI placed in their homes, and they and their caregivers were trained to use it. Use data were collected by Internet. Periodic visits evaluated BCI benefit and burden and quality of life.

Results: Over subsequent months, 12 (29% of the original 42) left the study because of death or rapid disease progression and 6 (14%) left because of decreased interest. Fourteen (33%) completed training and used the BCI independently, mainly for communication. Technical problems were rare. Patient and caregiver ratings indicated that BCI benefit exceeded burden. Quality of life remained stable. Of those not lost to the disease, half completed the study; all but 1 patient kept the BCI for further use.

Conclusion: The Wadsworth BCI home system can function reliably and usefully when operated by patients in their homes. BCIs that support communication are at present most suitable for people who are severely disabled but are otherwise in stable health. Improvements in BCI convenience and performance, including some now underway, should increase the number of people who find them useful and the extent to which they are used.10aAll clinical neurophysiology10aAll Neuromuscular Disease10aEvoked Potentials10avisual1 aWolpaw, Jonathan1 aBedlack, RS1 aReda, DJ1 aRinger, RJ1 aBanks, PG1 aVaughan, TM1 aHeckman, SM1 aMcCrane, LM1 aCarmack, CS1 aWinden, S1 aMcFarland, DJ1 aSellers, EW1 aShi, H1 aPaine, T1 aHiggins, DS1 aLo, AC1 aPatwa, HS1 aHill, KJ1 aHuang, GS1 aRuff, RL  uhttp://n.neurology.org/content/neurology/early/2018/06/27/WNL.0000000000005812.full.pdf00393nas a2200109   4500008004100000245002700041210002700068260001200095520007800107100002100185856007700206       2018                        eng d00aMcDowell Award Lecture0 aMcDowell Award Lecture  c05/20183 aBurke Neurological Research Inst, Weill-Cornell Sch Med, White Plains, NY1 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2018/mcdowell-award-lecture00482nas a2200097   4500008004100000245012300041210006900164260001200233100002100245856011800266       2018                        eng d00aNational Center for Neuromodulation for Rehabilitation Workshop, Medical University of South Carolina, Charleston, SC.0 aNational Center for Neuromodulation for Rehabilitation Workshop   c11/20181 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2018/national-center-neuromodulation-rehabilitation-workshop-medical00478nas a2200109   4500008004100000245006400041210006400105260001200169520005600181100002100237856011000258       2018                        eng d00aNeuromodulation for Rehabilitation after Spinal Cord Injury0 aNeuromodulation for Rehabilitation after Spinal Cord Injury  c08/20183 aNANS Summer Series, New York City, NY, August, 20181 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2018/neuromodulation-rehabilitation-after-spinal-cord-injury00432nas a2200097   4500008004100000245007200041210006900113260001200182100002100194856011900215       2018                        eng d00aNeuroRehabilitation CME Course, Harvard Medical School, Waltham, MA0 aNeuroRehabilitation CME Course Harvard Medical School Waltham MA  c06/20181 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2018/neurorehabilitation-cme-course-harvard-medical-school-waltham-ma00444nas a2200097   4500008004100000245007800041210006900119260001200188100002100200856012500221       2018                        eng d00aNew York State Spinal Cord Injury Research Board Symposium, New York, NY.0 aNew York State Spinal Cord Injury Research Board Symposium New Y  c10/20181 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2018/new-york-state-spinal-cord-injury-research-board-symposium-new-york-ny00408nas a2200109   4500008004100000245002600041210002600067260001200093520009600105100002100201856007600222       2018                        eng d00aOrganizer and Speaker0 aOrganizer and Speaker  c05/20183 aNeuroethics Symposium, Seventh International Brain-Computer Interface Meeting, Asilomar, CA1 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2018/organizer-and-speaker00462nas a2200109   4500008004100000245008500041210006900126260001200195520000600207100002100213856011800234       2018                        eng d00aProgress in Clinical Motor Control Symposium, Penn State Univ, State College, PA0 aProgress in Clinical Motor Control Symposium Penn State Univ Sta  c07/20183 a 1 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2018/progress-clinical-motor-control-symposium-penn-state-univ-state01870nas a2200265   4500008004100000022001400041245008400055210006900139260001200208300001200220490000700232520108800239653002501327653001301352653002701365653002501392653001501417653001901432653001801451100001601469700001601485700001801501700002101519856006401540       2018                        eng d  a1878-747900aRetraining Reflexes: Clinical Translation of Spinal Reflex Operant Conditioning0 aRetraining Reflexes Clinical Translation of Spinal Reflex Operan  c07/2018  a669-6830 v153 aNeurological disorders, such as spinal cord injury, stroke, traumatic brain injury, cerebral palsy, and multiple sclerosis cause motor impairments that are a huge burden at the individual, family, and societal levels. Spinal reflex abnormalities contribute to these impairments. Spinal reflex measurements play important roles in characterizing and monitoring neurological disorders and their associated motor impairments, such as spasticity, which affects nearly half of those with neurological disorders. Spinal reflexes can also serve as therapeutic targets themselves. Operant conditioning protocols can target beneficial plasticity to key reflex pathways; they can thereby trigger wider plasticity that improves impaired motor skills, such as locomotion. These protocols may complement standard therapies such as locomotor training and enhance functional recovery. This paper reviews the value of spinal reflexes and the therapeutic promise of spinal reflex operant conditioning protocols; it also considers the complex process of translating this promise into clinical reality.10aclinical translation10aH-Reflex10aneurological disorders10aoperant conditioning10aplasticity10aRehabilitation10aspinal reflex1 aEftekhar, A1 aNorton, JJS1 aMcDonough, CM1 aWolpaw, Jonathan  uhttps://link.springer.com/article/10.1007/s13311-018-0643-200423nas a2200097   4500008004100000245007000041210006700111260001200178100002100190856011400211       2018                        eng d00aSpinal Cord Plasticity in Motor Control Symposium, San Diego, CA.0 aSpinal Cord Plasticity in Motor Control Symposium San Diego CA  c11/20181 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2018/spinal-cord-plasticity-motor-control-symposium-san-diego-ca00599nas a2200157   4500008004100000245009100041210006900132260001200201100001500213700001700228700001600245700001900261700001500280700002100295856012500316       2018                        eng d00aTowards operant conditioning of the flexor carpi radialis: Methods and initial results0 aTowards operant conditioning of the flexor carpi radialis Method  c11/20181 aNorton, J.1 aEftekhar, A.1 aHeckman, S.1 aBarnes, J., H.1 aMcCane, L.1 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2018/towards-operant-conditioning-flexor-carpi-radialis-methods-and-initial00442nas a2200109   4500008004100000245004500041210004400086260001200130520008100142100002100223856008800244       2017                        eng d00aActivity-Dependent Plasticity in the CNS0 aActivityDependent Plasticity in the CNS  c07/20173 aNIH Short Course in Adaptive Neurotechnologies, Wadsworth Center, Albany, NY1 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2017/activity-dependent-plasticity-cns00445nas a2200097   4500008004100000245008900041210006900130260001200199100002100211856011500232       2017                        eng d00aCenter for Brain Plasticity and Recovery, Georgetown Univ. Med. Ctr., Washington, DC0 aCenter for Brain Plasticity and Recovery Georgetown Univ Med Ctr  c11/20171 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2017/center-brain-plasticity-and-recovery-georgetown-univ-med-ctr00384nas a2200109   4500008004100000245003400041210003400075260001200109520004800121100002100169856008400190       2017                        eng d00aDemystifying Medicine Lecture0 aDemystifying Medicine Lecture  c04/20173 aNational Institutes of Health, Bethesda, MD1 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2017/demystifying-medicine-lecture00439nas a2200097   4500008004100000245007700041210006900118260001200187100002100199856012100220       2017                        eng d00aDistinguished Scholar Lecture Series, University of Delaware, Newark, DE0 aDistinguished Scholar Lecture Series University of Delaware Newa  c11/20171 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2017/distinguished-scholar-lecture-series-university-delaware-newark-de01542nas a2200193   4500008004100000022001400041245004000055210003800095260000800133300001200141490000600153520102900159653002901188653002001217653001901237100002201256700002101278856004901299       2017                        eng d  a2468-451100aEEG-based brain-computer interfaces0 aEEGbased braincomputer interfaces  cOct  a194-2000 v43 aBrain–Computer Interfaces (BCIs) are real-time computer-based systems that translate brain signals into useful commands. To date most applications have been demonstrations of proof-of-principle; widespread use by people who could benefit from this technology requires further development. Improvements in current EEG recording technology are needed. Better sensors would be easier to apply, more comfortable for the user, and produce higher quality and more stable signals. Although considerable effort has been devoted to evaluating classifiers using public datasets, more attention to real-time signal processing issues and to optimizing the mutually adaptive interaction between the brain and the BCI are essential for improving BCI performance. Further development of applications is also needed, particularly applications of BCI technology to rehabilitation. The design of rehabilitation applications hinges on the nature of BCI control and how it might be used to induce and guide beneficial plasticity in the brain.10abrain-computer interface10aneurotechnology10aRehabilitation1 aMcFarland, D., J.1 aWolpaw, Jonathan  uhttps://www.ncbi.nlm.nih.gov/pubmed/2143819300386nas a2200109   4500008004100000245002000041210002000061260001200081520009200093100002100185856007000206       2017                        eng d00aInvited Speaker0 aInvited Speaker  c04/20173 aDepartment of Rehabilitation Medicine, Emory University School of Medicine, Atlanta, GA1 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2017/invited-speaker00446nas a2200097   4500008004100000245009000041210006900131260001200200100002100212856011500233       2017                        eng d00aNational Center of Neuromodulation for Rehabilitation (NM4R) Workshop, Charleston, SC0 aNational Center of Neuromodulation for Rehabilitation NM4R Works  c10/20171 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2017/national-center-neuromodulation-rehabilitation-nm4r-workshop00432nas a2200097   4500008004100000245007200041210006900113260001200182100002100194856011900215       2017                        eng d00aNeuroRehabilitation CME Course, Harvard Medical School, Waltham, MA0 aNeuroRehabilitation CME Course Harvard Medical School Waltham MA  c06/20171 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2017/neurorehabilitation-cme-course-harvard-medical-school-waltham-ma00434nas a2200145   4500008004100000022001400041245005500055210005400110260000800164300001600172490000800188100002100196700002300217856004800240       2017                        eng d  a1469-779300aNothing either good or bad but action makes it so.0 aNothing either good or bad but action makes it so  cFeb  a1003–10040 v5951 aWolpaw, Jonathan1 aThompson, Aiko, K.  uhttp://www.ncbi.nlm.nih.gov/pubmed/2819801900431nas a2200097   4500008004100000245007300041210006900114260001200183100002100195856011700216       2017                        eng d00aPlenary Lecture, Summer School on Neurorehabilitation, Baiona, Spain0 aPlenary Lecture Summer School on Neurorehabilitation Baiona Spai  c09/20171 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2017/plenary-lecture-summer-school-neurorehabilitation-baiona-spain00969nas a2200193   4500008004100000022001400041245007600055210006900131260000800200300001100208490000700219520037900226100002600605700002500631700002600656700002400682700002100706856004800727       2017                        eng d  a1741-255200aPrediction of subjective ratings of emotional pictures by EEG features.0 aPrediction of subjective ratings of emotional pictures by EEG fe  cFeb  a0160090 v143 aEmotion dysregulation is an important aspect of many psychiatric disorders. Brain-computer interface (BCI) technology could be a powerful new approach to facilitating therapeutic self-regulation of emotions. One possible BCI method would be to provide stimulus-specific feedback based on subject-specific electroencephalographic (EEG) responses to emotion-eliciting stimuli.1 aMcFarland, Dennis, J.1 aParvaz, Muhammad, A.1 aSarnacki, William, A.1 aGoldstein, Rita, Z.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/2793477600405nas a2200097   4500008004100000245006500041210006200106260001200168100002100180856010600201       2017                        eng d00aProgress in Motor Control IX, University of Miami, Miami, FL0 aProgress in Motor Control IX University of Miami Miami FL  c07/20171 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2017/progress-motor-control-ix-university-miami-miami-fl02456nas a2200157   4500008004100000022001400041245011700055210006900172260000800241520191100249100002502160700002102185700002102206700002302227856004802250       2017                        eng d  a1557-904200aSpinal transection alters external urethral sphincter activity during spontaneous voiding in freely-moving rats.0 aSpinal transection alters external urethral sphincter activity d  cMay3 aThe rat is a commonly used model for the study of lower urinary tract function before and after spinal cord injury. We have previously reported that in unanesthetized, freely-moving rats, although phasic external urethral sphincter (EUS) activity (bursting) is most common during micturition, productive voiding can occur in the absence of bursting, which differs from results seen in anesthetized or unanesthetized restrained animals. The purpose of the present study was to characterize EUS behavior in unanesthetized, freely-moving rats before and after mid-thoracic (T8) or thoraco-lumbar (T13-L1) spinal transection to determine how EUS behavior after spinal cord injury differs from that seen in anesthetized or unanesthetized restrained rats. Several abnormalities became evident that were comparable after transection at either level including: repetitive non-voiding EUS contractions; increased prevalence, intensity and duration of EUS bursting; decreased rate of urine evacuation during bursting; increased void size and decreased number of daily voids; shorter inter-burst silent period and increased frequency of bursting; and loss of the direct linear relationships that are evident in intact animals between void size and bursting silent period. These data suggest that transection-induced delayed initiation of EUS bursting allows co-contraction of the bladder and the EUS that prevents or limits urine evacuation, resulting in a detrusor-sphincter dyssynergia-like phenomenon. In addition, the higher-than-normal frequency at which EUS bursting occurs after transection is associated with shorter silent periods during which urine typically flows, which interferes with voiding by slowing the rate of urine evacuation. That results were comparable after either transection suggests that the central pattern generator responsible for EUS bursting is located caudal to the L1 spinal segment.1 aLaPallo, Brandon, K.1 aWolpaw, Jonathan1 aChen, Xiang Yang1 aCarp, Jonathan, S.  uhttp://www.ncbi.nlm.nih.gov/pubmed/2846773602131nas a2200253   4500008004100000245007200041210006900113260000900182300001400191490000700205520141800212653001301630653001901643653002501662653001501687653001901702653001601721100001301737700001301750700001301763700002201776700002101798856005801819       2017                        eng d00aWhy New Spinal Cord Plasticity Does Not Disrupt Old Motor Behaviors0 aWhy New Spinal Cord Plasticity Does Not Disrupt Old Motor Behavi  cJuly  a8198-82060 v373 aWhen new motor learning changes the spinal cord, old behaviors are not impaired; their key features are preserved by additional compensatory plasticity. To explore the mechanisms responsible for this compensatory plasticity, we transected the spinal dorsal ascending tract before or after female rats acquired a new behavior—operantly conditioned increase or decrease in the right soleus H-reflex—and examined an old behavior—locomotion. Neither spinal dorsal ascending tract transection nor H-reflex conditioning alone impaired locomotion. Nevertheless, when spinal dorsal ascending tract transection and H-reflex conditioning were combined, the rats developed a limp and a tilted posture that correlated in direction and magnitude with the H-reflex change. When the right H-reflex was increased by conditioning, the right step lasted longer than the left and the right hip was higher than the left; when the right H-reflex was decreased by conditioning, the opposite occurred. These results indicate that ascending sensory input guides the compensatory plasticity that normally prevents the plasticity underlying H-reflex change from impairing locomotion. They support the concept of the state of the spinal cord as a negotiated equilibrium that reflects the concurrent influences of all the behaviors in an individual's repertoire; and they support the new therapeutic strategies this concept introduces.10aH-Reflex10amotor learning10aoperant conditioning10aplasticity10aRehabilitation10aSpinal Cord1 aChen, Yi1 aChen, Lu1 aWang, Yu1 aChen, Xiang, Yang1 aWolpaw, Jonathan  uhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC5566867/00470nas a2200097   4500008004100000245011100041210006900152260001200221100002100233856011800254       2016                        eng d00a50th Anniversary Symposium, Spinal Cord Injury Center, Heidelberg University Hospital, Heidelberg, Germany0 a50th Anniversary Symposium Spinal Cord Injury Center Heidelberg   c06/20161 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2016/50th-anniversary-symposium-spinal-cord-injury-center-heidelberg01650nas a2200205   4500008004100000022001400041245008000055210006900135260000800204300001600212490000800228520106300236653001601299100002101315700001301336700001301349700001301362700002101375856004801396       2016                        eng d  a1522-159800aAblation of the inferior olive prevents H-reflex down-conditioning in rats.0 aAblation of the inferior olive prevents Hreflex downconditioning  cMar  a1630–16360 v1153 aWe evaluated the role of the inferior olive (IO) in acquisition of the spinal cord plasticity that underlies H-reflex down-conditioning, a simple motor skill. The IO was chemically ablated before a 50-day exposure to an operant conditioning protocol that rewarded a smaller soleus H-reflex. In normal rats, down-conditioning succeeds (i.e., H-reflex size decreases at least 20%) in 80% of animals. Down-conditioning failed in every IO-ablated rat (P< 0.001 vs. normal rats). IO ablation itself had no long-term effect on H-reflex size. These results indicate that the IO is essential for acquisition of a down-conditioned H-reflex. With previous data, they support the hypothesis that IO and cortical inputs to cerebellum enable the cerebellum to guide sensorimotor cortex plasticity that produces and maintains the spinal cord plasticity that underlies the down-conditioned H-reflex. They help to further define H-reflex conditioning as a model for understanding motor learning and as a new approach to enhancing functional recovery after trauma or disease.10aSpinal Cord1 aChen, Xiang Yang1 aWang, Yu1 aChen, Yi1 aChen, Lu1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/2679288800442nas a2200109   4500008004100000245004500041210004400086260001200130520008100142100002100223856008800244       2016                        eng d00aActivity-Dependent Plasticity in the CNS0 aActivityDependent Plasticity in the CNS  c07/20163 aNIH Short Course in Adaptive Neurotechnologies, Wadsworth Center, Albany, NY1 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2016/activity-dependent-plasticity-cns00462nas a2200097   4500008004100000245009600041210006900137260001200206100002100218856012500239       2016                        eng d00aAtlantic Health Symposium, Atlantic Neuroscience Institute, Overlook Med Center, Summit, NJ0 aAtlantic Health Symposium Atlantic Neuroscience Institute Overlo  c04/20161 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2016/atlantic-health-symposium-atlantic-neuroscience-institute-overlook-med01079nas a2200181   4500008004100000022001400041245011000055210006900165260000800234300001400242490000700256520049600263100002500759700002100784700002100805700002300826856004800849       2016                        eng d  a1520-677700aContribution of the external urethral sphincter to urinary void size in unanesthetized unrestrained rats.0 aContribution of the external urethral sphincter to urinary void   cAug  a696–7020 v353 aIn anesthetized rats, voiding is typically associated with phasic activation (bursting) of the external urethral sphincter (EUS). During spontaneous voiding in unanesthetized, unrestrained rats, EUS bursting is the most common form of EUS activity exhibited, but it is not necessary for productive voiding to occur. The aim of the present study was to determine which aspects of EUS activity contributed to void size during bursting and non-bursting voiding in conscious, freely moving rats.1 aLaPallo, Brandon, K.1 aWolpaw, Jonathan1 aChen, Xiang Yang1 aCarp, Jonathan, S.  uhttp://www.ncbi.nlm.nih.gov/pubmed/2599507400445nas a2200097   4500008004100000245008000041210006900121260001200190100002100202856012400223       2016                        eng d00aDepartment of Cognitive Science, Rensselaer Polytechnic Institute, Troy, NY0 aDepartment of Cognitive Science Rensselaer Polytechnic Institute  c04/20161 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2016/department-cognitive-science-rensselaer-polytechnic-institute-troy-ny00494nas a2200097   4500008004100000245012800041210006900169260001200238100002100250856012500271       2016                        eng d00aDepartments of Rehabilitation and Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA0 aDepartments of Rehabilitation and Biomedical Engineering Emory U  c03/20161 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2016/departments-rehabilitation-and-biomedical-engineering-emory-university00438nas a2200097   4500008004100000245007700041210006900118260001200187100002100199856012000220       2016                        eng d00aGrand Rounds, Department of Neurology, Columbia University, New York, NY0 aGrand Rounds Department of Neurology Columbia University New Yor  c04/20161 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2016/grand-rounds-department-neurology-columbia-university-new-york-ny02087nas a2200193   4500008004100000022001400041245008700055210006900142260000800211300001600219490000800235520152100243100002101764700001301785700001301798700001301811700002101824856004801845       2016                        eng d  a1522-159800aThe inferior olive is essential for long-term maintenance of a simple motor skill.0 ainferior olive is essential for longterm maintenance of a simple  cOct  a1946–19550 v1163 aThe inferior olive (IO) is essential for operant down-conditioning of the rat soleus H-reflex, a simple motor skill. To evaluate the role of the IO in long-term maintenance of this skill, the H-reflex was down-conditioned over 50 days, the IO was chemically ablated, and down-conditioning continued for up to 102 more days. H-reflex size just before IO ablation averaged 62(±2 SE)% of its initial value (P < 0.001 vs. initial). After IO ablation, H-reflex size rose to 75-80% over ?10 days, remained there for ?30 days, rose over 10 days to above its initial value, and averaged 140(±14)% for the final 10 days of study (P < 0.01 vs. initial). This two-stage loss of down-conditioning maintenance correlated with IO neuronal loss (r = 0.75, P < 0.01) and was similar to the loss of down-conditioning that follows ablation of the cerebellar output nuclei dentate and interpositus. In control (i.e., unconditioned) rats, IO ablation has no long-term effect on H-reflex size. These results indicate that the IO is essential for long-term maintenance of a down-conditioned H-reflex. With previous data, they support the hypothesis that IO and cortical inputs to cerebellum combine to produce cerebellar plasticity that produces sensorimotor cortex plasticity that produces spinal cord plasticity that produces the smaller H-reflex. H-reflex down-conditioning appears to depend on a hierarchy of plasticity that may be guided by the IO and begin in the cerebellum. Similar hierarchies may underlie other motor learning.1 aChen, Xiang Yang1 aWang, Yu1 aChen, Yi1 aChen, Lu1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/2753536700457nas a2200097   4500008004100000245009100041210006900132260001200201100002100213856012500234       2016                        eng d00aKeynote Lecture, Neural Engineering Research Symposium, University of Miami, Miami, FL0 aKeynote Lecture Neural Engineering Research Symposium University  c10/20161 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2016/keynote-lecture-neural-engineering-research-symposium-university-miami00479nas a2200097   4500008004100000245012000041210006900161260001200230100002100242856011800263       2016                        eng d00a Keynote Speaker, Neuromodulation for Rehabilitation Workshop, Medical University of South Carolina, Charleston, SC0 aKeynote Speaker Neuromodulation for Rehabilitation Workshop Medi  c03/20161 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2016/keynote-speaker-neuromodulation-rehabilitation-workshop-medical00367nas a2200097   4500008004100000245005400041210004700095260001200142100002100154856009400175       2016                        eng d00aThe Miami Project, University of Miami, Miami, FL0 aMiami Project University of Miami Miami FL  c10/20161 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2016/miami-project-university-miami-miami-fl00462nas a2200097   4500008004100000245010200041210006900143260001200212100002100224856011900245       2016                        eng d00aNeuromodulation for Rehabilitation Workshop, Medical University of South Carolina, Charleston, SC0 aNeuromodulation for Rehabilitation Workshop Medical University o  c10/20161 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2016/neuromodulation-rehabilitation-workshop-medical-university-south00390nas a2200097   4500008004100000245005800041210005500099260001200154100002100166856010500187       2016                        eng d00aPioneer Award Lecture, SPIE Conference, Baltimore, MD0 aPioneer Award Lecture SPIE Conference Baltimore MD  c04/20161 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2016/pioneer-award-lecture-spie-conference-baltimore-md00449nas a2200097   4500008004100000245008500041210006900126260001200195100002100207856012300228       2016                        eng d00aPlenary Lecture, International Conference on Neurorehabilitation, Segovia, Spain0 aPlenary Lecture International Conference on Neurorehabilitation   c10/20161 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2016/plenary-lecture-international-conference-neurorehabilitation-segovia00458nas a2200097   4500008004100000245010000041210006900141260001200210100002100222856011700243       2016                        eng d00aPresidential Lecture, Sixth Annual International Brain-Computer Interface Meeting, Asilomar, CA0 aPresidential Lecture Sixth Annual International BrainComputer In  c05/20161 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2016/presidential-lecture-sixth-annual-international-brain-computer00405nas a2200097   4500008004100000245006300041210006000104260001200164100002100176856011000197       2016                        eng d00aSession Chair, Neural Interfaces Conference, Baltimore, MD0 aSession Chair Neural Interfaces Conference Baltimore MD  c06/20161 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2016/session-chair-neural-interfaces-conference-baltimore-md00443nas a2200097   4500008004100000245007900041210006900120260001200189100002100201856012300222       2016                        eng d00aSymposium, International Conference on Neurorehabilitation, Segovia, Spain0 aSymposium International Conference on Neurorehabilitation Segovi  c10/20161 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2016/symposium-international-conference-neurorehabilitation-segovia-spain00448nas a2200097   4500008004100000245008700041210006900128260001200197100002100209856012000230       2016                        eng d00aSymposium, International Society of Electrophysiology and Kinesiology, Chicago, IL0 aSymposium International Society of Electrophysiology and Kinesio  c07/20161 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2016/symposium-international-society-electrophysiology-and-kinesiology00460nas a2200097   4500008004100000245009600041210006900137260001200206100002100218856012300239       2015                        eng d00aBiomedical Technology Research Centers Principal Investigator Annual Meeting, Rockville, MD0 aBiomedical Technology Research Centers Principal Investigator An  c03/20151 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2015/biomedical-technology-research-centers-principal-investigator-annual00997nas a2200181   4500008004100000022001400041245008500055210006900140260000800209300001100217490000700228520043500235653002400670100002600694700002600720700002100746856004800767       2015                        eng d  a1741-255200aEffects of training pre-movement sensorimotor rhythms on behavioral performance.0 aEffects of training premovement sensorimotor rhythms on behavior  cDec  a0660210 v123 aBrain-computer interface (BCI) technology might contribute to rehabilitation of motor function. This speculation is based on the premise that modifying the electroencephalographic (EEG) activity will modify behavior, a proposition for which there is limited empirical data. The present study asked whether learned modulation of pre-movement sensorimotor rhythm (SMR) activity can affect motor performance in normal human subjects.10asensorimotor cortex1 aMcFarland, Dennis, J.1 aSarnacki, William, A.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/2652911902314nas a2200229   4500008004100000022001400041245010300055210006900158260001200227300001200239490000800251520162300259653002901882653001101911653001301922653001801935653001601953100002501969700002101994700002102015856004802036       2015                        eng d  a1522-159800aElectrocorticographic activity over sensorimotor cortex and motor function in awake behaving rats.0 aElectrocorticographic activity over sensorimotor cortex and moto  c04/2015  a2232-410 v1133 a<p>Sensorimotor cortex exerts both short-term and long-term control over the spinal reflex pathways that serve motor behaviors. Better understanding of this control could offer new possibilities for restoring function after central nervous system trauma or disease. We examined the impact of ongoing sensorimotor cortex (SMC) activity on the largely monosynaptic pathway of the H-reflex, the electrical analog of the spinal stretch reflex. In 41 awake adult rats, we measured soleus electromyographic (EMG) activity, the soleus H-reflex, and electrocorticographic activity over the contralateral SMC while rats were producing steady-state soleus EMG activity. Principal component analysis of electrocorticographic frequency spectra before H-reflex elicitation consistently revealed three frequency bands: μβ (5-30 Hz), low γ (γ1; 40-85 Hz), and high γ (γ2; 100-200 Hz). Ongoing (i.e., background) soleus EMG amplitude correlated negatively with μβ power and positively with γ1 power. In contrast, H-reflex size correlated positively with μβ power and negatively with γ1 power, but only when background soleus EMG amplitude was included in the linear model. These results support the hypothesis that increased SMC activation (indicated by decrease in μβ power and/or increase in γ1 power) simultaneously potentiates the H-reflex by exciting spinal motoneurons and suppresses it by decreasing the efficacy of the afferent input. They may help guide the development of new rehabilitation methods and of brain-computer interfaces that use SMC activity as a substitute for lost or impaired motor outputs.</p>10abrain-computer interface10acortex10aH-Reflex10aMotor control10aSpinal Cord1 aBoulay, Chadwick, B.1 aChen, Xiang Yang1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/2563207600441nas a2200109   4500008004100000245004800041210004700089260001200136520007300148100002100221856008900242       2015                        eng d00aHow the CNS operates as a multi-user system0 aHow the CNS operates as a multiuser system  c04/20153 aPanel (Chairman), Neural Control of Movement Meeting, Charleston, SC1 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2015/how-cns-operates-multi-user-system00434nas a2200097   4500008004100000245007500041210006900116260001200185100002100197856011800218       2015                        eng d00aKavli Seminar, Center for Sensorimotor Neural Engineering, Seattle, WA0 aKavli Seminar Center for Sensorimotor Neural Engineering Seattle  c04/20151 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2015/kavli-seminar-center-sensorimotor-neural-engineering-seattle-wa00475nas a2200097   4500008004100000245011400041210006900155260001200224100002100236856012000257       2015                        eng d00aKeynote Address, College of Health Sciences Spring Research Symposium, University of Wisconsin, Milwaukee, WI0 aKeynote Address College of Health Sciences Spring Research Sympo  c05/20151 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2015/keynote-address-college-health-sciences-spring-research-symposium03835nas a2200301   4500008004100000022001400041245015300055210006900208260001200277520274700289653005303036653004003089653003503129653003403164653003303198653003503231100002003266700002203286700002603308700002103334700001903355700002103374700001903395700002603414700002103440700002403461856004803485       2015                        eng d  a1872-895200aP300-based brain-computer interface (BCI) event-related potentials (ERPs): People with amyotrophic lateral sclerosis (ALS) vs. age-matched controls.0 aP300based braincomputer interface BCI eventrelated potentials ER  c02/20153 a<p><b>OBJECTIVE: </b>Brain-computer interfaces (BCIs) aimed at restoring communication to people with severe neuromuscular disabilities often use event-related potentials (ERPs) in scalp-recorded EEG activity. Up to the present, most research and development in this area has been done in the laboratory with young healthy control subjects. In order to facilitate the development of BCI most useful to people with disabilities, the present study set out to: (1) determine whether people with amyotrophic lateral sclerosis (ALS) and healthy, age-matched volunteers (HVs) differ in the speed and accuracy of their ERP-based BCI use; (2) compare the ERP characteristics of these two groups; and (3) identify ERP-related factors that might enable improvement in BCI performance for people with disabilities.</p><p><b>METHODS: </b>Sixteen EEG channels were recorded while people with ALS or healthy age-matched volunteers (HVs) used a P300-based BCI. The subjects with ALS had little or no remaining useful motor control (mean ALS Functional Rating Scale-Revised 9.4 (±9.5SD) (range 0-25)). Each subject attended to a target item as the items in a 6×6 visual matrix flashed. The BCI used a stepwise linear discriminant function (SWLDA) to determine the item the user wished to select (i.e., the target item). Offline analyses assessed the latencies, amplitudes, and locations of ERPs to the target and non-target items for people with ALS and age-matched control subjects.</p><p><b>RESULTS: </b>BCI accuracy and communication rate did not differ significantly between ALS users and HVs. Although ERP morphology was similar for the two groups, their target ERPs differed significantly in the location and amplitude of the late positivity (P300), the amplitude of the early negativity (N200), and the latency of the late negativity (LN).</p><p><b>CONCLUSIONS: </b>The differences in target ERP components between people with ALS and age-matched HVs are consistent with the growing recognition that ALS may affect cortical function. The development of BCIs for use by this population may begin with studies in HVs but also needs to include studies in people with ALS. Their differences in ERP components may affect the selection of electrode montages, and might also affect the selection of presentation parameters (e.g., matrix design, stimulation rate).</p><p><b>SIGNIFICANCE: </b>P300-based BCI performance in people severely disabled by ALS is similar to that of age-matched control subjects. At the same time, their ERP components differ to some degree from those of controls. Attention to these differences could contribute to the development of BCIs useful to those with ALS and possibly to others with severe neuromuscular disabilities.</p>10aalternative and augmentative communication (AAC)10aamyotrophic lateral sclerosis (ALS)10aBrain-computer interface (BCI)10abrain-machine interface (BMI)10aelectroencephalography (EEG)10aevent-related potentials (ERP)1 aMcCane, Lynn, M1 aHeckman, Susan, M1 aMcFarland, Dennis, J.1 aTownsend, George1 aMak, Joseph, N1 aSellers, Eric, W1 aZeitlin, Debra1 aTenteromano, Laura, M1 aWolpaw, Jonathan1 aVaughan, Theresa, M  uhttp://www.ncbi.nlm.nih.gov/pubmed/2570394002092nas a2200217   4500008004100000022001400041245009800055210006900153260001200222300001100234490000700245520143300252653001301685653001501698653002301713653002701736653002001763100002201783700002101805856004801826       2015                        eng d  a1089-409800aRestoring walking after spinal cord injury: operant conditioning of spinal reflexes can help.0 aRestoring walking after spinal cord injury operant conditioning   c04/2015  a203-150 v213 a<p>People with incomplete spinal cord injury (SCI) frequently suffer motor disabilities due to spasticity and poor muscle control, even after conventional therapy. Abnormal spinal reflex activity often contributes to these problems. Operant conditioning of spinal reflexes, which can target plasticity to specific reflex pathways, can enhance recovery. In rats in which a right lateral column lesion had weakened right stance and produced an asymmetrical gait, up-conditioning of the right soleus H-reflex, which increased muscle spindle afferent excitation of soleus, strengthened right stance and eliminated the asymmetry. In people with hyperreflexia due to incomplete SCI, down-conditioning of the soleus H-reflex improved walking speed and symmetry. Furthermore, modulation of electromyographic activity during walking improved bilaterally, indicating that a protocol that targets plasticity to a specific pathway can trigger widespread plasticity that improves recovery far beyond that attributable to the change in the targeted pathway. These improvements were apparent to people in their daily lives. They reported walking faster and farther, and noted less spasticity and better balance. Operant conditioning protocols could be developed to modify other spinal reflexes or corticospinal connections; and could be combined with other therapies to enhance recovery in people with SCI or other neuromuscular disorders.</p>10aLearning10aLocomotion10aspinal cord injury10aspinal cord plasticity10aspinal reflexes1 aThompson, Aiko, K1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/2463695400451nas a2200097   4500008004100000245009000041210006900131260001200200100002100212856012000233       2015                        eng d00aSpinal Cord Injury Grand Rounds, Medical University of South Carolina, Charleston, SC0 aSpinal Cord Injury Grand Rounds Medical University of South Caro  c04/20151 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2015/spinal-cord-injury-grand-rounds-medical-university-south-carolina00389nas a2200097   4500008004100000245005800041210005600099260001200155100002100167856010300188       2015                        eng d00aSummer School on Neurorehabilitation, Valencia, Spain0 aSummer School on Neurorehabilitation Valencia Spain  c09/20151 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2015/summer-school-neurorehabilitation-valencia-spain00429nas a2200097   4500008004100000245007200041210006900113260001200182100002100194856011600215       2015                        eng d00aSymposium, American Congress of Rehabilitation Medicine, Dallas, TX0 aSymposium American Congress of Rehabilitation Medicine Dallas TX  c10/20151 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2015/symposium-american-congress-rehabilitation-medicine-dallas-tx00427nas a2200097   4500008004100000245007500041210006900116260001200185100002100197856011100218       2015                        eng d00aSymposium, Annual Meeting of the Society for Neuroscience, Chicago, IL0 aSymposium Annual Meeting of the Society for Neuroscience Chicago  c10/20151 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2015/symposium-annual-meeting-society-neuroscience-chicago-il02012nas a2200229   4500008004100000022001400041245004900055210004800104260001200152300001100164490000800175520137600183653003401559653001301593653002501606653001901631653002301650653001801673100002201691700002101713856004801734       2015                        eng d  a1875-785500aTargeted neuroplasticity for rehabilitation.0 aTargeted neuroplasticity for rehabilitation  c03/2015  a157-720 v2183 a<p>An operant-conditioning protocol that bases reward on the electromyographic response produced by a specific CNS pathway can change that pathway. For example, in both animals and people, an operant-conditioning protocol can increase or decrease the spinal stretch reflex or its electrical analog, the H-reflex. Reflex change is associated with plasticity in the pathway of the reflex as well as elsewhere in the spinal cord and brain. Because these pathways serve many different behaviors, the plasticity produced by this conditioning can change other behaviors. Thus, in animals or people with partial spinal cord injuries, appropriate reflex conditioning can improve locomotion. Furthermore, in people with spinal cord injuries, appropriate reflex conditioning can trigger widespread beneficial plasticity. This wider plasticity appears to reflect an iterative process through which the multiple behaviors in the individual's repertoire negotiate the properties of the spinal neurons and synapses that they all use. Operant-conditioning protocols are a promising new therapeutic method that could complement other rehabilitation methods and enhance functional recovery. Their successful use requires strict adherence to appropriately designed procedures, as well as close attention to accommodating and engaging the individual subject in the conditioning process.</p>10aactivity-dependent plasticity10aH-Reflex10aoperant conditioning10aRehabilitation10aspinal cord injury10aspinal reflex1 aThompson, Aiko, K1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/2589013600407nas a2200097   4500008004100000245006300041210006100104260001200165100002100177856011100198       2014                        eng d00aAmerican Psychological Association Ann Mtg, Washington, DC0 aAmerican Psychological Association Ann Mtg Washington DC  c08/20141 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2014/american-psychological-association-ann-mtg-washington-dc02595nas a2200421   4500008004100000022001400041245009200055210006900147260001200216300001100228490000700239520137400246653001001620653000901630653003401639653002801673653003001701653002801731653002701759653003501786653001101821653001101832653000901843653001601852653001901868653002301887653002801910653001801938100002001956700002101976700002601997700001902023700001902042700001902061700002102080700002402101856004802125       2014                        eng d  a2167-922300aBrain-computer interface (BCI) evaluation in people with amyotrophic lateral sclerosis.0 aBraincomputer interface BCI evaluation in people with amyotrophi  c06/2014  a207-150 v153 aBrain-computer interfaces (BCIs) might restore communication to people severely disabled by amyotrophic lateral sclerosis (ALS) or other disorders. We sought to: 1) define a protocol for determining whether a person with ALS can use a visual P300-based BCI; 2) determine what proportion of this population can use the BCI; and 3) identify factors affecting BCI performance. Twenty-five individuals with ALS completed an evaluation protocol using a standard 6 × 6 matrix and parameters selected by stepwise linear discrimination. With an 8-channel EEG montage, the subjects fell into two groups in BCI accuracy (chance accuracy 3%). Seventeen averaged 92 (± 3)% (range 71-100%), which is adequate for communication (G70 group). Eight averaged 12 (± 6)% (range 0-36%), inadequate for communication (L40 subject group). Performance did not correlate with disability: 11/17 (65%) of G70 subjects were severely disabled (i.e. ALSFRS-R < 5). All L40 subjects had visual impairments (e.g. nystagmus, diplopia, ptosis). P300 was larger and more anterior in G70 subjects. A 16-channel montage did not significantly improve accuracy. In conclusion, most people severely disabled by ALS could use a visual P300-based BCI for communication. In those who could not, visual impairment was the principal obstacle. For these individuals, auditory P300-based BCIs might be effective.10aAdult10aAged10aAmyotrophic Lateral Sclerosis10aBiofeedback, Psychology10abrain-computer interfaces10aCommunication Disorders10aElectroencephalography10aEvent-Related Potentials, P30010aFemale10aHumans10aMale10aMiddle Aged10aOnline Systems10aPhotic Stimulation10aPsychomotor Performance10aReaction Time1 aMcCane, Lynn, M1 aSellers, Eric, W1 aMcFarland, Dennis, J.1 aMak, Joseph, N1 aCarmack, Steve1 aZeitlin, Debra1 aWolpaw, Jonathan1 aVaughan, Theresa, M  uhttp://www.ncbi.nlm.nih.gov/pubmed/2455584300366nas a2200109   4500008004100000245002900041210002800070260001200098520004700110100002100157856007800178       2014                        eng d00aC. Warren Olanow Lecture0 aC Warren Olanow Lecture  c06/20143 aMt. Sinai School of Medicine, New York, NY1 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2014/c-warren-olanow-lecture00422nas a2200109   4500008004100000245005300041210005300094260001200147520003200159100002100191856010000212       2014                        eng d00aDistinguished Lectures in Biological Engineering0 aDistinguished Lectures in Biological Engineering  c03/20143 aEPFL, Lausanne, Switzerland1 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2014/distinguished-lectures-biological-engineering00373nas a2200109   4500008004100000245002000041210002000061260001200081520007700093100002100170856007200191       2014                        eng d00aInvited Speaker0 aInvited Speaker  c04/20143 aInternational Collaboration on Repair Discoveries (ICORD), Vancouver, BC1 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2014/invited-speaker-000349nas a2200109   4500008004100000245002000041210002000061260001200081520005500093100002100148856007000169       2014                        eng d00aInvited Speaker0 aInvited Speaker  c03/20143 aBrain Research Institute, ETH, Zurich, Switzerland1 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2014/invited-speaker00358nas a2200109   4500008004100000245002000041210002000061260001200081520006400093100002100157856007000178       2014                        eng d00aKeynote Speaker0 aKeynote Speaker  c04/20143 aUNYTE Translational Research Network, Univ of Rochester, NY1 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2014/keynote-speaker02675nas a2200325   4500008004100000022001400041245010000055210006900155260001200224300001200236490000800248520178700256653001202043653002602055653001102081653001302092653001302105653001502118653000902133653000902142653002502151653002502176100001302201700001302214700001902227700001302246700002102259700002102280856004802301       2014                        eng d  a1522-159800aLocomotor impact of beneficial or nonbeneficial H-reflex conditioning after spinal cord injury.0 aLocomotor impact of beneficial or nonbeneficial Hreflex conditio  c03/2014  a1249-580 v1113 aWhen new motor learning changes neurons and synapses in the spinal cord, it may affect previously learned behaviors that depend on the same spinal neurons and synapses. To explore these effects, we used operant conditioning to strengthen or weaken the right soleus H-reflex pathway in rats in which a right spinal cord contusion had impaired locomotion. When up-conditioning increased the H-reflex, locomotion improved. Steps became longer, and step-cycle asymmetry (i.e., limping) disappeared. In contrast, when down-conditioning decreased the H-reflex, locomotion did not worsen. Steps did not become shorter, and asymmetry did not increase. Electromyographic and kinematic analyses explained how H-reflex increase improved locomotion and why H-reflex decrease did not further impair it. Although the impact of up-conditioning or down-conditioning on the H-reflex pathway was still present during locomotion, only up-conditioning affected the soleus locomotor burst. Additionally, compensatory plasticity apparently prevented the weaker H-reflex pathway caused by down-conditioning from weakening the locomotor burst and further impairing locomotion. The results support the hypothesis that the state of the spinal cord is a "negotiated equilibrium" that serves all the behaviors that depend on it. When new learning changes the spinal cord, old behaviors undergo concurrent relearning that preserves or improves their key features. Thus, if an old behavior has been impaired by trauma or disease, spinal reflex conditioning, by changing a specific pathway and triggering a new negotiation, may enable recovery beyond that achieved simply by practicing the old behavior. Spinal reflex conditioning protocols might complement other neurorehabilitation methods and enhance recovery.10aAnimals10aConditioning, Operant10aFemale10aH-Reflex10aLearning10aLocomotion10aMale10aRats10aRats, Sprague-Dawley10aSpinal Cord Injuries1 aChen, Yi1 aChen, Lu1 aLiu, Rongliang1 aWang, Yu1 aChen, Xiang Yang1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/2437128802577nas a2200301   4500008004100000022001400041245010600055210006900161260001200230300001200242490000800254520171500262653001201977653002601989653002102015653001102036653001502047653000902062653002502071653001202096653001402108653001602122100002402138700002102162700002102183700002302204856004802227       2014                        eng d  a1522-146600aLong-term recording of external urethral sphincter EMG activity in unanesthetized, unrestrained rats.0 aLongterm recording of external urethral sphincter EMG activity i  c08/2014  aF485-970 v3073 a<p>The external urethral sphincter muscle (EUS) plays an important role in urinary function and often contributes to urinary dysfunction. EUS study would benefit from methodology for longitudinal recording of electromyographic activity (EMG) in unanesthetized animals, but this muscle is a poor substrate for chronic intramuscular electrodes, and thus the required methodology has not been available. We describe a method for long-term recording of EUS EMG by implantation of fine wires adjacent to the EUS that are secured to the pubic bone. Wires pass subcutaneously to a skull-mounted plug and connect to the recording apparatus by a flexible cable attached to a commutator. A force transducer-mounted cup under a metabolic cage collected urine, allowing recording of EUS EMG and voided urine weight without anesthesia or restraint. Implant durability permitted EUS EMG recording during repeated (up to 3 times weekly) 24-h sessions for more than 8 wk. EMG and voiding properties were stable over weeks 2-8. The degree of EUS phasic activity (bursting) during voiding was highly variable, with an average of 25% of voids not exhibiting bursting. Electrode implantation adjacent to the EUS yielded stable EMG recordings over extended periods and eliminated the confounding effects of anesthesia, physical restraint, and the potential for dislodgment of the chronically implanted intramuscular electrodes. These results show that micturition in unanesthetized, unrestrained rats is usually, but not always, associated with EUS bursting. This methodology is applicable to studying EUS behavior during progression of gradually evolving disease and injury models and in response to therapeutic interventions.</p>10aAnimals10aElectrodes, Implanted10aElectromyography10aFemale10aPubic Bone10aRats10aRats, Sprague-Dawley10aUrethra10aUrination10aUrodynamics1 aLaPallo, Brandon, K1 aWolpaw, Jonathan1 aChen, Xiang Yang1 aCarp, Jonathan, S.  uhttp://www.ncbi.nlm.nih.gov/pubmed/2499089500354nas a2200109   4500008004100000245002700041210002700068260001200095520003900107100002100146856007700167       2014                        eng d00aNeurology Grand Rounds0 aNeurology Grand Rounds  c04/20143 aPenn State University, Hershey, PA1 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2014/neurology-grand-rounds02145nas a2200217   4500008004100000022001400041245008500055210006900140260001200209300000700221490000600228520150000234653001301734653002401747653001501771653002301786653002701809100002201836700002101858856004801879       2014                        eng d  a1662-514500aOperant conditioning of spinal reflexes: from basic science to clinical therapy.0 aOperant conditioning of spinal reflexes from basic science to cl  c03/2014  a250 v83 aNew appreciation of the adaptive capabilities of the nervous system, recent recognition that most spinal cord injuries are incomplete, and progress in enabling regeneration are generating growing interest in novel rehabilitation therapies. Here we review the 35-year evolution of one promising new approach, operant conditioning of spinal reflexes. This work began in the late 1970's as basic science; its purpose was to develop and exploit a uniquely accessible model for studying the acquisition and maintenance of a simple behavior in the mammalian central nervous system (CNS). The model was developed first in monkeys and then in rats, mice, and humans. Studies with it showed that the ostensibly simple behavior (i.e., a larger or smaller reflex) rests on a complex hierarchy of brain and spinal cord plasticity; and current investigations are delineating this plasticity and its interactions with the plasticity that supports other behaviors. In the last decade, the possible therapeutic uses of reflex conditioning have come under study, first in rats and then in humans. The initial results are very exciting, and they are spurring further studies. At the same time, the original basic science purpose and the new clinical purpose are enabling and illuminating each other in unexpected ways. The long course and current state of this work illustrate the practical importance of basic research and the valuable synergy that can develop between basic science questions and clinical needs.10aH-Reflex10alearning and memory10aLocomotion10aspinal cord injury10aspinal cord plasticity1 aThompson, Aiko, K1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/2467244102554nas a2200241   4500008004100000022001400041245016400055210006900219260001200288300001200300490000800312520178000320653001302100653001502113653001902128653001602147653001502163100002102178700002202199700002102221700002202242856004802264       2014                        eng d  a1522-159800aOperant conditioning of the soleus H-reflex does not induce long-term changes in the gastrocnemius H-reflexes and does not disturb normal locomotion in humans.0 aOperant conditioning of the soleus Hreflex does not induce longt  c09/2014  a1439-460 v1123 a<p>In normal animals, operant conditioning of the spinal stretch reflex or the H-reflex has lesser effects on synergist muscle reflexes. In rats and people with incomplete spinal cord injury (SCI), soleus H-reflex operant conditioning can improve locomotion. We studied in normal humans the impact of soleus H-reflex down-conditioning on medial (MG) and lateral gastrocnemius (LG) H-reflexes and on locomotion. Subjects completed 6 baseline and 30 conditioning sessions. During conditioning trials, the subject was encouraged to decrease soleus H-reflex size with the aid of visual feedback. Every sixth session, MG and LG H-reflexes were measured. Locomotion was assessed before and after conditioning. In successfully conditioned subjects, the soleus H-reflex decreased 27.2%. This was the sum of within-session (task dependent) adaptation (13.2%) and across-session (long term) change (14%). The MG H-reflex decreased 14.5%, due mainly to task-dependent adaptation (13.4%). The LG H-reflex showed no task-dependent adaptation or long-term change. No consistent changes were detected across subjects in locomotor H-reflexes, EMG activity, joint angles, or step symmetry. Thus, in normal humans, soleus H-reflex down-conditioning does not induce long-term changes in MG/LG H-reflexes and does not change locomotion. In these subjects, task-dependent adaptation of the soleus H-reflex is greater than it is in people with SCI, whereas long-term change is less. This difference from results in people with SCI is consistent with the fact that long-term change is beneficial in people with SCI, since it improves locomotion. In contrast, in normal subjects, long-term change is not beneficial and may necessitate compensatory plasticity to preserve satisfactory locomotion.</p>10aLearning10aplasticity10aRehabilitation10aSpinal Cord10asynergists1 aMakihara, Yukiko1 aSegal, Richard, L1 aWolpaw, Jonathan1 aThompson, Aiko, K  uhttp://www.ncbi.nlm.nih.gov/pubmed/2494421602425nas a2200289   4500008004100000022001400041245008700055210006900142260001200211300001200223490000800235520161100243653002601854653001301880653001501893653001101908653001801919653001901937653002301956653002701979100001302006700001302019700001302032700002102045700002102066856004802087       2014                        eng d  a1522-159800aPersistent beneficial impact of H-reflex conditioning in spinal cord-injured rats.0 aPersistent beneficial impact of Hreflex conditioning in spinal c  c11/2014  a2374-810 v1123 a<p>Operant conditioning of a spinal cord reflex can improve locomotion in rats and humans with incomplete spinal cord injury. This study examined the persistence of its beneficial effects. In rats in which a right lateral column contusion injury had produced asymmetric locomotion, up-conditioning of the right soleus H-reflex eliminated the asymmetry while down-conditioning had no effect. After the 50-day conditioning period ended, the H-reflex was monitored for 100 [±9 (SD)] (range 79-108) more days and locomotion was then reevaluated. After conditioning ended in up-conditioned rats, the H-reflex continued to increase, and locomotion continued to improve. In down-conditioned rats, the H-reflex decrease gradually disappeared after conditioning ended, and locomotion at the end of data collection remained as impaired as it had been before and immediately after down-conditioning. The persistence (and further progression) of H-reflex increase but not H-reflex decrease in these spinal cord-injured rats is consistent with the fact that up-conditioning improved their locomotion while down-conditioning did not. That is, even after up-conditioning ended, the up-conditioned H-reflex pathway remained adaptive because it improved locomotion. The persistence and further enhancement of the locomotor improvement indicates that spinal reflex conditioning protocols might supplement current therapies and enhance neurorehabilitation. They may be especially useful when significant spinal cord regeneration becomes possible and precise methods for retraining the regenerated spinal cord are needed.</p>10aH-reflex conditioning10aLearning10aLocomotion10aMemory10aMotor control10aRehabilitation10aspinal cord injury10aspinal cord plasticity1 aChen, Yi1 aChen, Lu1 aWang, Yu1 aWolpaw, Jonathan1 aChen, Xiang Yang  uhttp://www.ncbi.nlm.nih.gov/pubmed/2514354203178nas a2200421   4500008004100000022001400041245009800055210006900153260001200222300001100234490000700245520196800252653001002220653000902230653001502239653002402254653003002278653003602308653002702344653002102371653003102392653001102423653001102434653000902445653002402454653001602478653001702494653002202511653002802533100002502561700001602586700001902602700002002621700002202641700002102663700002402684856004802708       2014                        eng d  a1741-255200aA practical, intuitive brain-computer interface for communicating 'yes' or 'no' by listening.0 apractical intuitive braincomputer interface for communicating ye  c06/2014  a0350030 v113 aOBJECTIVE:
Previous work has shown that it is possible to build an EEG-based binary brain-computer interface system (BCI) driven purely by shifts of attention to auditory stimuli. However, previous studies used abrupt, abstract stimuli that are often perceived as harsh and unpleasant, and whose lack of inherent meaning may make the interface unintuitive and difficult for beginners. We aimed to establish whether we could transition to a system based on more natural, intuitive stimuli (spoken words 'yes' and 'no') without loss of performance, and whether the system could be used by people in the locked-in state.
APPROACH:
We performed a counterbalanced, interleaved within-subject comparison between an auditory streaming BCI that used beep stimuli, and one that used word stimuli. Fourteen healthy volunteers performed two sessions each, on separate days. We also collected preliminary data from two subjects with advanced amyotrophic lateral sclerosis (ALS), who used the word-based system to answer a set of simple yes-no questions.
MAIN RESULTS:
The N1, N2 and P3 event-related potentials elicited by words varied more between subjects than those elicited by beeps. However, the difference between responses to attended and unattended stimuli was more consistent with words than beeps. Healthy subjects' performance with word stimuli (mean 77% ± 3.3 s.e.) was slightly but not significantly better than their performance with beep stimuli (mean 73% ± 2.8 s.e.). The two subjects with ALS used the word-based BCI to answer questions with a level of accuracy similar to that of the healthy subjects.
SIGNIFICANCE:
Since performance using word stimuli was at least as good as performance using beeps, we recommend that auditory streaming BCI systems be built with word stimuli to make the system more pleasant and intuitive. Our preliminary data show that word-based streaming BCI is a promising tool for communication by people who are locked in.10aAdult10aAged10aAlgorithms10aAuditory Perception10abrain-computer interfaces10aCommunication Aids for Disabled10aElectroencephalography10aEquipment Design10aEquipment Failure Analysis10aFemale10aHumans10aMale10aMan-Machine Systems10aMiddle Aged10aQuadriplegia10aTreatment Outcome10aUser-Computer Interface1 aHill, Jeremy, Jeremy1 aRicci, Erin1 aHaider, Sameah1 aMcCane, Lynn, M1 aHeckman, Susan, M1 aWolpaw, Jonathan1 aVaughan, Theresa, M  uhttp://www.ncbi.nlm.nih.gov/pubmed/2483827800447nas a2200097   4500008004100000245008100041210006900122260001200191100002100203856012500224       2014                        eng d00aSatellite Symposium, Spinal Cord Plasticity in Motor Control, Washington, DC0 aSatellite Symposium Spinal Cord Plasticity in Motor Control Wash  c11/20141 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2014/satellite-symposium-spinal-cord-plasticity-motor-control-washington-dc01203nas a2200277   4500008004100000022001400041245009000055210006900145260001200214300001000226490000700236520041500243653001200658653002600670653001300696653001100709653001700720653002100737653002400758653001100782653001600793653002500809100002200834700002100856856004800877       2014                        eng d  a1538-300800aThe simplest motor skill: mechanisms and applications of reflex operant conditioning.0 asimplest motor skill mechanisms and applications of reflex opera  c04/2014  a82-900 v423 aOperant conditioning protocols can change spinal reflexes gradually, which are the simplest behaviors. This article summarizes the evidence supporting two propositions: that these protocols provide excellent models for defining the substrates of learning and that they can induce and guide plasticity to help restore skills, such as locomotion, that have been impaired by spinal cord injury or other disorders.10aAnimals10aConditioning, Operant10aH-Reflex10aHumans10aMotor Skills10aMuscle, Skeletal10aNeuronal Plasticity10aReflex10aSpinal Cord10aSpinal Cord Injuries1 aThompson, Aiko, K1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/2450873800383nas a2200097   4500008004100000245005600041210005400097260001200151100002100163856010100184       2014                        eng d00aSummer School on Neurorehabilitation, Baiona, Spain0 aSummer School on Neurorehabilitation Baiona Spain  c09/20141 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2014/summer-school-neurorehabilitation-baiona-spain00427nas a2200097   4500008004100000245007200041210006800113260001200181100002100193856011500214       2014                        eng d00a Symposium, American Society of Neurorehabilitation, Washington, DC0 aSymposium American Society of Neurorehabilitation Washington DC  c11/20141 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2014/symposium-american-society-neurorehabilitation-washington-dc00366nas a2200109   4500008004100000245002200041210002200063260001200085520006400097100002100161856007400182       2014                        eng d00aSymposium Speaker0 aSymposium Speaker  c05/20143 aSensorimotor Rehabilitation, University of Montreal, Canada1 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2014/symposium-speaker-000370nas a2200109   4500008004100000245002200041210002200063260001200085520007000097100002100167856007200188       2014                        eng d00aSymposium Speaker0 aSymposium Speaker  c06/20143 aInternational Conference on NeuroRehabilitation, Aalborg, Denmark1 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2014/symposium-speaker02668nas a2200241   4500008004100000022001400041245009000055210006900145260001200214300001100226490000700237520188700244653002802131653003502159653003402194653003102228653004102259653001902300100001202319700002602331700002102357856004802378       2013                        eng d  a1741-255200aAdaptive Laplacian filtering for sensorimotor rhythm-based brain-computer interfaces.0 aAdaptive Laplacian filtering for sensorimotor rhythmbased brainc  c02/2013  a0160020 v103 aOBJECTIVE:
Sensorimotor rhythms (SMRs) are 8-30 Hz oscillations in the electroencephalogram (EEG) recorded from the scalp over sensorimotor cortex that change with movement and/or movement imagery. Many brain-computer interface (BCI) studies have shown that people can learn to control SMR amplitudes and can use that control to move cursors and other objects in one, two or three dimensions. At the same time, if SMR-based BCIs are to be useful for people with neuromuscular disabilities, their accuracy and reliability must be improved substantially. These BCIs often use spatial filtering methods such as common average reference (CAR), Laplacian (LAP) filter or common spatial pattern (CSP) filter to enhance the signal-to-noise ratio of EEG. Here, we test the hypothesis that a new filter design, called an 'adaptive Laplacian (ALAP) filter', can provide better performance for SMR-based BCIs.
APPROACH:
An ALAP filter employs a Gaussian kernel to construct a smooth spatial gradient of channel weights and then simultaneously seeks the optimal kernel radius of this spatial filter and the regularization parameter of linear ridge regression. This optimization is based on minimizing the leave-one-out cross-validation error through a gradient descent method and is computationally feasible.
MAIN RESULTS:
Using a variety of kinds of BCI data from a total of 22 individuals, we compare the performances of ALAP filter to CAR, small LAP, large LAP and CSP filters. With a large number of channels and limited data, ALAP performs significantly better than CSP, CAR, small LAP and large LAP both in classification accuracy and in mean-squared error. Using fewer channels restricted to motor areas, ALAP is still superior to CAR, small LAP and large LAP, but equally matched to CSP.
SIGNIFICANCE:
Thus, ALAP may help to improve the accuracy and robustness of SMR-based BCIs.10aassistive communication10abrain computer interface (BCI)10abrain-machine interface (BMI)10aelectroencephalogram (EEG)10aleave-one-out (LOO) cross-validation10aspatial filter1 aLu, Jun1 aMcFarland, Dennis, J.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/2322087901152nas a2200145   4500008004100000022001400041245003100055210002900086300001200115490000800127520078900135653001300924100002100937856004800958       2013                        eng d  a0072-975200aBrain-computer interfaces.0 aBraincomputer interfaces  a67–740 v1103 aBrain-computer interfaces (BCIs) are systems that give their users communication and control capabilities that do not depend on muscles. The user&#39;s intentions are determined from activity recorded by electrodes on the scalp, on the cortical surface, or within the brain. BCIs can enable people who are paralyzed by amyotrophic lateral sclerosis (ALS), brainstem stroke, or other disorders to convey their needs and wishes to others, to operate word-processing programs or other software, or possibly to control a wheelchair or a neuroprosthesis. BCI technology might also augment rehabilitation protocols aimed at restoring useful motor function. With continued development and clinical implementation, BCIs could substantially improve the lives of those with severe disabilities.10aSoftware1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/2331263102449nas a2200241   4500008004100000022001400041245010300055210006900158260001200227300001600239490000700255520172600262653001301988653001502001653002502016653001502041653001902056653001502075100002302090700002502113700002102138856004802159       2013                        eng d  a1529-240100aOperant conditioning of a spinal reflex can improve locomotion after spinal cord injury in humans.0 aOperant conditioning of a spinal reflex can improve locomotion a  c02/2013  a2365–23750 v333 aOperant conditioning protocols can modify the activity of specific spinal cord pathways and can thereby affect behaviors that use these pathways. To explore the therapeutic application of these protocols, we studied the impact of down-conditioning the soleus H-reflex in people with impaired locomotion caused by chronic incomplete spinal cord injury. After a baseline period in which soleus H-reflex size was measured and locomotion was assessed, subjects completed either 30 H-reflex down-conditioning sessions (DC subjects) or 30 sessions in which the H-reflex was simply measured [unconditioned (UC) subjects], and locomotion was reassessed. Over the 30 sessions, the soleus H-reflex decreased in two-thirds of the DC subjects (a success rate similar to that in normal subjects) and remained smaller several months later. In these subjects, locomotion became faster and more symmetrical, and the modulation of EMG activity across the step cycle increased bilaterally. Furthermore, beginning about halfway through the conditioning sessions, all of these subjects commented spontaneously that they were walking faster and farther in their daily lives, and several noted less clonus, easier stepping, and/or other improvements. The H-reflex did not decrease in the other DC subjects or in any of the UC subjects; and their locomotion did not improve. These results suggest that reflex-conditioning protocols can enhance recovery of function after incomplete spinal cord injuries and possibly in other disorders as well. Because they are able to target specific spinal pathways, these protocols could be designed to address each individual's particular deficits, and might thereby complement other rehabilitation methods.10aLearning10aLocomotion10aoperant conditioning10aplasticity10aRehabilitation10aspasticity1 aThompson, Aiko, K.1 aPomerantz, Ferne, R.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/2339266601657nas a2200217   4500008004100000022001400041245008100055210006900136260001200205300001400217490000700231520101900238653001901257653001501276653001901291653001601310100002301326700002101349700002101370856004801391       2013                        eng d  a1097-459800aSoleus H-reflex operant conditioning changes the H-reflex recruitment curve.0 aSoleus Hreflex operant conditioning changes the Hreflex recruitm  c04/2013  a539–5440 v473 aINTRODUCTION:
Operant conditioning can gradually change the human soleus H-reflex. The protocol conditions the reflex near M-wave threshold. In this study we examine its impact on the reflexes at other stimulus strengths.
METHODS:
H-reflex recruitment curves were obtained before and after a 24-session exposure to an up-conditioning (HRup) or a down-conditioning (HRdown) protocol and were compared.
RESULTS:
In both HRup and HRdown subjects, conditioning affected the entire H-reflex recruitment curve. In 5 of 6 HRup and 3 of 6 HRdown subjects, conditioning elevated (HRup) or depressed (HRdown), respectively, the entire curve. In the other HRup subject or the other 3 HRdown subjects, the curve was shifted to the left or to the right, respectively.
CONCLUSIONS:
H-reflex conditioning does not simply change the H-reflex to a stimulus of particular strength; it also changes the H-reflexes to stimuli of different strengths. Thus, it is likely to affect many actions in which this pathway participates.10amotor learning10aplasticity10aRehabilitation10aSpinal Cord1 aThompson, Aiko, K.1 aChen, Xiang Yang1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/2328110701311nas a2200193   4500008004100000022002500041245005000066210004900116260002800165520065200193653001800845653003000863653000900893653003700902100002100939700002100960700001900981856011701000       2012                        eng d  aISBN: 978-019538885500aBCIs That Use Electrocorticographic Activity.0 aBCIs That Use Electrocorticographic Activity  bOxford University Press3 aThis chapter discusses the potential of electrocorticography (ECoG) as a clinically useful brain-computer interface signal modality. ECoG has greater amplitude, higher topographical resolution, and a much broader frequency range than scalp-recorded electroencephalography and is less susceptible to artifacts. With current and foreseeable recording methodologies, ECoG is likely to have greater long-term stability than intracortically recorded signals. Furthermore, it can more readily be recorded from larger cortical areas, and it requires much lower digitization rates, thus greatly reducing the power requirements of wholly implanted systems.10abrain signals10abrain-computer interfaces10aECoG10aintracortically recorded signals1 aWolpaw, Jonathan1 aWinter-Wolpaw, E1 aSchalk, Gerwin  uhttp://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780195388855.001.0001/acprof-9780195388855-chapter-01502228nas a2200181   4500008004100000022001400041245004300055210004100098260001200139300001400151490000700165520173200172653002801904100002001932700002501952700002101977856004801998       2012                        eng d  a1942-554600aBrain-computer interfaces in medicine.0 aBraincomputer interfaces in medicine  c03/2012  a268–2790 v873 aBrain-computer interfaces (BCIs) acquire brain signals, analyze them, and translate them into commands that are relayed to output devices that carry out desired actions. BCIs do not use normal neuromuscular output pathways. The main goal of BCI is to replace or restore useful function to people disabled by neuromuscular disorders such as amyotrophic lateral sclerosis, cerebral palsy, stroke, or spinal cord injury. From initial demonstrations of electroencephalography-based spelling and single-neuron-based device control, researchers have gone on to use electroencephalographic, intracortical, electrocorticographic, and other brain signals for increasingly complex control of cursors, robotic arms, prostheses, wheelchairs, and other devices. Brain-computer interfaces may also prove useful for rehabilitation after stroke and for other disorders. In the future, they might augment the performance of surgeons or other medical professionals. Brain-computer interface technology is the focus of a rapidly growing research and development enterprise that is greatly exciting scientists, engineers, clinicians, and the public in general. Its future achievements will depend on advances in 3 crucial areas. Brain-computer interfaces need signal-acquisition hardware that is convenient, portable, safe, and able to function in all environments. Brain-computer interface systems need to be validated in long-term studies of real-world use by people with severe disabilities, and effective and viable models for their widespread dissemination must be implemented. Finally, the day-to-day and moment-to-moment reliability of BCI performance must be improved so that it approaches the reliability of natural muscle-based function.10aUser-Computer Interface1 aShih, Jerry, J.1 aKrusienski, Dean, J.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/2232536401486nas a2200205   4500008004100000022001400041245010200055210006900157260001200226300001600238490000800254520087300262653001601135100001301151700001301164700001301177700002101190700002101211856004801232       2012                        eng d  a1522-159800aCortical stimulation causes long-term changes in H-reflexes and spinal motoneuron GABA receptors.0 aCortical stimulation causes longterm changes in Hreflexes and sp  c11/2012  a2668–26780 v1083 aThe cortex gradually modifies the spinal cord during development, throughout later life, and in response to trauma or disease. The mechanisms of this essential function are not well understood. In this study, weak electrical stimulation of rat sensorimotor cortex increased the soleus H-reflex, increased the numbers and sizes of GABAergic spinal interneurons and GABAergic terminals on soleus motoneurons, and decreased GABA(A) and GABA(B) receptor labeling in these motoneurons. Several months after the stimulation ended the interneuron and terminal increases had disappeared, but the H-reflex increase and the receptor decreases remained. The changes in GABAergic terminals and GABA(B) receptors accurately predicted the changes in H-reflex size. The results reveal a new long-term dimension to cortical-spinal interactions and raise new therapeutic possibilities.10aSpinal Cord1 aWang, Yu1 aChen, Yi1 aChen, Lu1 aWolpaw, Jonathan1 aChen, Xiang Yang  uhttp://www.ncbi.nlm.nih.gov/pubmed/2293371802062nas a2200241   4500008004100000022001400041245012200055210006900177260001200246300001100258490000600269520128800275653002801563100002001591700002601611700002401637700002101661700002401682700002301706700002201729700002101751856004801772       2012                        eng d  a1741-255200aEEG correlates of P300-based brain-computer interface (BCI) performance in people with amyotrophic lateral sclerosis.0 aEEG correlates of P300based braincomputer interface BCI performa  c04/2012  a0260140 v93 aThe purpose of this study was to identify electroencephalography (EEG) features that correlate with P300-based brain-computer interface (P300 BCI) performance in people with amyotrophic lateral sclerosis (ALS). Twenty people with ALS used a P300 BCI spelling application in copy-spelling mode. Three types of EEG features were found to be good predictors of P300 BCI performance: (1) the root-mean-square amplitude and (2) the negative peak amplitude of the event-related potential to target stimuli (target ERP) at Fz, Cz, P3, Pz, and P4; and (3) EEG theta frequency (4.5-8 Hz) power at Fz, Cz, P3, Pz, P4, PO7, PO8 and Oz. A statistical prediction model that used a subset of these features accounted for &gt;60% of the variance in copy-spelling performance (p &lt; 0.001, mean R(2)?= 0.6175). The correlations reflected between-subject, rather than within-subject, effects. The results enhance understanding of performance differences among P300 BCI users. The predictors found in this study might help in: (1) identifying suitable candidates for long-term P300 BCI operation; (2) assessing performance online. Further work on within-subject effects needs to be done to establish whether P300 BCI user performance could be improved by optimizing one or more of these EEG features.10aUser-Computer Interface1 aMak, Joseph, N.1 aMcFarland, Dennis, J.1 aVaughan, Theresa, M1 aMcCane, Lynn, M.1 aTsui, Phillippa, Z.1 aZeitlin, Debra, J.1 aSellers, Eric, W.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/2235050100508nas a2200157   4500008004100000022001900041245004000060210003900100260002800139100001900167700001300186700002000199700002100219700002100240856008900261       2012                        eng d  a978-019538885500aHardware and Software Technologies.0 aHardware and Software Technologies  bOxford University Press1 aSchalk, Gerwin1 aGuger, C1 aWilson, Adam, J1 aWolpaw, Jonathan1 aWinter-Wolpaw, E  uhttps://www.neurotechcenter.org/publications/2012/hardware-and-software-technologies00457nas a2200145   4500008004100000022001400041245005800055210005700113260001200170300002800182490000800210653002400218100002100242856004800263       2012                        eng d  a1460-215600aHarnessing neuroplasticity for clinical applications.0 aHarnessing neuroplasticity for clinical applications  c04/2012  ae215; author reply e2160 v13510aNeuronal Plasticity1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/2237493601738nas a2200241   4500008004100000022001400041245009800055210006900153260001200222300001400234490000700248520099700255653001501252653003101267653001801298653001401316653003001330100002101360700002301381700002101404700002301425856004801448       2012                        eng d  a1097-459800aH-reflex modulation in the human medial and lateral gastrocnemii during standing and walking.0 aHreflex modulation in the human medial and lateral gastrocnemii   c01/2012  a116–1250 v453 aINTRODUCTION:
The soleus H-reflex is dynamically modulated during walking. However, modulation of the gastrocnemii H-reflexes has not been studied systematically.
METHODS:
The medial and lateral gastrocnemii (MG and LG) and soleus H-reflexes were measured during standing and walking in humans.
RESULTS:
Maximum H-reflex amplitude was significantly smaller in MG (mean 1.1 mV) or LG (1.1 mV) than in soleus (3.3 mV). Despite these size differences, the reflex amplitudes of the three muscles were positively correlated. The MG and LG H-reflexes were phase- and task-dependently modulated in ways similar to the soleus H-reflex.
CONCLUSIONS:
Although there are anatomical and physiological differences between the soleus and gastrocnemii muscles, the reflexes of the three muscles are similarly modulated during walking and between standing and walking. Our findings support the hypothesis that these reflexes are synergistically modulated during walking to facilitate ongoing movement.10aLocomotion10aphase-dependent modulation10aspinal reflex10asynergist10atask-dependent modulation1 aMakihara, Yukiko1 aSegal, Richard, L.1 aWolpaw, Jonathan1 aThompson, Aiko, K.  uhttp://www.ncbi.nlm.nih.gov/pubmed/2219031702099nas a2200241   4500008004100000022001400041245011200055210006900167260001200236300001000248490000700258520136500265653001501630653001001645653002701655653001101682653001701693653002801710100002401738700002601762700002101788856004801809       2012                        eng d  a1873-274700aValue of amplitude, phase, and coherence features for a sensorimotor rhythm-based brain-computer interface.0 aValue of amplitude phase and coherence features for a sensorimot  c01/2012  a130-40 v873 aMeasures that quantify the relationship between two or more brain signals are drawing attention as neuroscientists explore the mechanisms of large-scale integration that enable coherent behavior and cognition. Traditional Fourier-based measures of coherence have been used to quantify frequency-dependent relationships between two signals. More recently, several off-line studies examined phase-locking value (PLV) as a possible feature for use in brain-computer interface (BCI) systems. However, only a few individuals have been studied and full statistical comparisons among the different classes of features and their combinations have not been conducted. The present study examines the relative BCI performance of spectral power, coherence, and PLV, alone and in combination. The results indicate that spectral power produced classification at least as good as PLV, coherence, or any possible combination of these measures. This may be due to the fact that all three measures reflect mainly the activity of a single signal source (i.e., an area of sensorimotor cortex). This possibility is supported by the finding that EEG signals from different channels generally had near-zero phase differences. Coherence, PLV, and other measures of inter-channel relationships may be more valuable for BCIs that use signals from more than one distinct cortical source.10aAlgorithms10aBrain10aElectroencephalography10aHumans10aMotor Cortex10aUser-Computer Interface1 aKrusienski, Dean, J1 aMcFarland, Dennis, J.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/2198598400447nas a2200145   4500008004100000022001400041245006100055210005900116260001200175300001200187490000700199100002600206700002100232856004800253       2011                        eng d  a0001-078200aBrain-Computer Interfaces for Communication and Control.0 aBrainComputer Interfaces for Communication and Control  c05/2011  a60–660 v541 aMcFarland, Dennis, J.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/2198482202364nas a2200217   4500008004100000022001400041245011800055210006900173260001200242300001800254490000700272520171000279653000901989653001901998100001302017700001302030700001302043700002102056700002102077856004802098       2011                        eng d  a1529-240100aOperant conditioning of rat soleus H-reflex oppositely affects another H-reflex and changes locomotor kinematics.0 aOperant conditioning of rat soleus Hreflex oppositely affects an  c08/2011  a11370–113750 v313 aH-reflex conditioning is a model for studying the plasticity associated with a new motor skill. We are exploring its effects on other reflexes and on locomotion. Rats were implanted with EMG electrodes in both solei (SOL(R) and SOL(L)) and right quadriceps (QD(R)), and stimulating cuffs on both posterior tibial (PT) nerves and right posterior femoral nerve. When SOL(R) EMG remained in a defined range, PT(R) stimulation just above M-response threshold elicited the SOL(R) H-reflex. Analogous procedures elicited the QD(R) and SOL(L) H-reflexes. After a control period, each rat was exposed for 50 d to a protocol that rewarded SOL(R) H-reflexes that were above (HRup rats) or below (HRdown rats) a criterion. HRup conditioning increased the SOL(R) H-reflex to 214 ± 37% (mean ± SEM) of control (p = 0.02) and decreased the QD(R) H-reflex to 71 ± 26% (p = 0.06). HRdown conditioning decreased the SOL(R) H-reflex to 69 ± 2% (p < 0.001) and increased the QD(R) H-reflex to 121 ± 7% (p = 0.02). These changes remained during locomotion. The SOL(L) H-reflex did not change. During the stance phase of locomotion, ankle plantarflexion increased in HRup rats and decreased in HRdown rats, hip extension did the opposite, and hip height did not change. The plasticity that changes the QD(R) H-reflex and locomotor kinematics may be inevitable (i.e., reactive) due to the ubiquity of activity-dependent CNS plasticity, and/or necessary (i.e., compensatory) to preserve other behaviors (e.g., locomotion) that would otherwise be disturbed by the change in the SOL(R) H-reflex pathway. The changes in joint angles, coupled with the preservation of hip height, suggest that compensatory plasticity did occur.10aRats10aSprague-Dawley1 aChen, Yi1 aChen, Lu1 aWang, Yu1 aWolpaw, Jonathan1 aChen, Xiang Yang  uhttp://www.ncbi.nlm.nih.gov/pubmed/2181369602447nas a2200229   4500008004100000022001400041245007700055210006700132260001200199300001400211490000800225520176000233653002901993653002002022653000902042100002602051700002602077700002102103700002402124700002102148856004802169       2011                        eng d  a1872-895200aThe P300-based brain-computer interface (BCI): effects of stimulus rate.0 aP300based braincomputer interface BCI effects of stimulus rate  c04/2011  a731–7370 v1223 aOBJECTIVE:
Brain-computer interface technology can restore communication and control to people who are severely paralyzed. We have developed a non-invasive BCI based on the P300 event-related potential that uses an 8×9 matrix of 72 items that flash in groups of 6. Stimulus presentation rate (i.e., flash rate) is one of several parameters that could affect the speed and accuracy of performance. We studied performance (i.e., accuracy and characters/min) on copy spelling as a function of flash rate.
METHODS:
In the first study of six BCI users, stimulus-on and stimulus-off times were equal and flash rate was 4, 8, 16, or 32 Hz. In the second study of five BCI users, flash rate was varied by changing either the stimulus-on or stimulus-off time.
RESULTS:
For all users, lower flash rates gave higher accuracy. The flash rate that gave the highest characters/min varied across users, ranging from 8 to 32 Hz. However, variations in stimulus-on and stimulus-off times did not themselves significantly affect accuracy. Providing feedback did not affect results in either study suggesting that offline analyses should readily generalize to online performance. However there do appear to be session-specific effects that can influence the generalizability of classifier results.
CONCLUSIONS:
The results show that stimulus presentation (i.e., flash) rate affects the accuracy and speed of P300 BCI performance.
SIGNIFICANCE:
These results extend the range over which slower flash rates increase the amplitude of the P300. Considering also presentation time, the optimal rate differs among users, and thus should be set empirically for each user. Optimal flash rate might also vary with other parameters such as the number of items in the matrix.10abrain-computer interface10aneuroprosthesis10aP3001 aMcFarland, Dennis, J.1 aSarnacki, William, A.1 aTownsend, George1 aVaughan, Theresa, M1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/2106797001319nas a2200205   4500008004100000022001400041245008200055210006900137260001200206300001400218490000800232520070000240653001500940653002900955653000800984100002600992700002601018700002101044856004801065       2011                        eng d  a1872-678X00aShould the parameters of a BCI translation algorithm be continually adapted?.0 aShould the parameters of a BCI translation algorithm be continua  c07/2011  a103–1070 v1993 aPeople with or without motor disabilities can learn to control sensorimotor rhythms (SMRs) recorded from the scalp to move a computer cursor in one or more dimensions or can use the P300 event-related potential as a control signal to make discrete selections. Data collected from individuals using an SMR-based or P300-based BCI were evaluated offline to estimate the impact on performance of continually adapting the parameters of the translation algorithm during BCI operation. The performance of the SMR-based BCI was enhanced by adaptive updating of the feature weights or adaptive normalization of the features. In contrast, P300 performance did not benefit from either of these procedures.10aadaptation10abrain-computer interface10aEEG1 aMcFarland, Dennis, J.1 aSarnacki, William, A.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/2157100403279nas a2200337   4500008004100000022001400041245011400055210006900169260001200238300001200250490000700262520231800269653001502587653001002602653001002612653001802622653002702640653001102667653001102678653000902689653001602698653004102714653002002755100001802775700001902793700002202812700001902834700002102853700001902874856004802893       2011                        eng d  a1095-957200aSpatiotemporal dynamics of electrocorticographic high gamma activity during overt and covert word repetition.0 aSpatiotemporal dynamics of electrocorticographic high gamma acti  c02/2011  a2960-720 v543 a<p><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">Language is one of the defining abilities of humans. Many studies have characterized the neural correlates of different aspects of language processing. However, the imaging techniques typically used in these studies were limited in either their temporal or spatial resolution. Electrocorticographic (ECoG) recordings from the surface of the&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">brain</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;combine high spatial with high temporal resolution and thus could be a valuable tool for the study of neural correlates of language function. In this study, we defined the spatiotemporal dynamics of ECoG activity during a word repetition task in nine human subjects. ECoG was recorded while each subject overtly or covertly repeated words that were presented either visually or auditorily. ECoG amplitudes in the high gamma (HG) band confidently tracked neural changes associated with stimulus presentation and with the subject's verbal response. Overt word production was primarily associated with HG changes in the superior and middle parts of temporal lobe, Wernicke's area, the supramarginal gyrus, Broca's area, premotor cortex (PMC), primary motor cortex. Covert word production was primarily associated with HG changes in superior temporal lobe and the supramarginal gyrus. Acoustic processing from both auditory stimuli as well as the subject's own voice resulted in HG power changes in superior temporal lobe and Wernicke's area. In summary, this study represents a comprehensive characterization of overt and covert speech using electrophysiological imaging with high spatial and temporal resolution. It thereby complements the findings of previous neuroimaging studies of language and thus further adds to&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">current</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;understanding of word processing in humans.</span></p>10aAdolescent10aAdult10aBrain10aBrain Mapping10aElectroencephalography10aFemale10aHumans10aMale10aMiddle Aged10aSignal Processing, Computer-Assisted10aVerbal Behavior1 aPei, Xiao-Mei1 aLeuthardt, E C1 aGaona, Charles, M1 aBrunner, Peter1 aWolpaw, Jonathan1 aSchalk, Gerwin  uhttp://www.ncbi.nlm.nih.gov/pubmed/2102978400539nas a2200157   4500008004100000022001400041245010700055210006900162260001200231300001100243490000600254653002800260100002400288700002100312856004800333       2011                        eng d  a1741-255200aSpecial issue containing contributions from the Fourth International Brain-Computer Interface Meeting.0 aSpecial issue containing contributions from the Fourth Internati  c04/2011  a0202010 v810aUser-Computer Interface1 aVaughan, Theresa, M1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/2143652201826nas a2200217   4500008004100000022001400041245007300055210006900128260001200197300001600209490000800225520117900233653002901412653000801441653001801449100002501467700002101492700002101513700002601534856004801560       2011                        eng d  a1872-895200aTrained modulation of sensorimotor rhythms can affect reaction time.0 aTrained modulation of sensorimotor rhythms can affect reaction t  c09/2011  a1820–18260 v1223 aOBJECTIVE:
Brain-computer interface (BCI) technology might be useful for rehabilitation of motor function. This speculation is based on the premise that modifying the EEG will modify behavior, a proposition for which there is limited empirical data. The present study examined the possibility that voluntary modulation of sensorimotor rhythm (SMR) can affect motor behavior in normal human subjects.
METHODS:
Six individuals performed a cued-reaction task with variable warning periods. A typical variable foreperiod effect was associated with SMR desynchronization. SMR features that correlated with reaction times were then used to control a two-target cursor movement BCI task. Following successful BCI training, an uncued reaction time task was embedded within the cursor movement task.
RESULTS:
Voluntarily increasing SMR beta rhythms was associated with longer reaction times than decreasing SMR beta rhythms.
CONCLUSIONS:
Voluntary modulation of EEG SMR can affect motor behavior.
SIGNIFICANCE:
These results encourage studies that integrate BCI training into rehabilitation protocols and examine its capacity to augment restoration of useful motor function.10abrain-computer interface10aEEG10aReaction Time1 aBoulay, Chadwick, B.1 aSarnacki, W., A.1 aWolpaw, Jonathan1 aMcFarland, Dennis, J.  uhttp://www.ncbi.nlm.nih.gov/pubmed/2141136601801nas a2200181   4500008004100000022001400041245006700055210006200122260001200184300001400196490000700210520125900217653002801476100002201504700002401526700002101550856004801571       2010                        eng d  a1471-180X00aA brain-computer interface for long-term independent home use.0 abraincomputer interface for longterm independent home use  c10/2010  a449–4550 v113 aOur objective was to develop and validate a new brain-computer interface (BCI) system suitable for long-term independent home use by people with severe motor disabilities. The BCI was used by a 51-year-old male with ALS who could no longer use conventional assistive devices. Caregivers learned to place the electrode cap, add electrode gel, and turn on the BCI. After calibration, the system allowed the user to communicate via EEG. Re-calibration was performed remotely (via the internet), and BCI accuracy assessed in periodic tests. Reports of BCI usefulness by the user and the family were also recorded. Results showed that BCI accuracy remained at 83% (r = -.07, n.s.) for over 2.5 years (1.4% expected by chance). The BCI user and his family state that the BCI had restored his independence in social interactions and at work. He uses the BCI to run his NIH-funded research laboratory and to communicate via e-mail with family, friends, and colleagues. In addition to this first user, several other similarly disabled people are now using the BCI in their daily lives. In conclusion, long-term independent home use of this BCI system is practical for severely disabled people, and can contribute significantly to quality of life and productivity.10aUser-Computer Interface1 aSellers, Eric, W.1 aVaughan, Theresa, M1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/2058394702079nas a2200205   4500008004100000022001400041245010100055210006900156260001200225300001400237490000700251520145100258653002901709653002801738653000801766653001001774653002001784100002101804856004801825       2010                        eng d  a1940-102700aBrain-computer interface research comes of age: traditional assumptions meet emerging realities.0 aBraincomputer interface research comes of age traditional assump  c11/2010  a351–3530 v423 aBrain-computer interfaces (BCIs) could provide important new communication and control options for people with severe motor disabilities. Most BCI research to date has been based on 4 assumptions that: (a) intended actions are fully represented in the cerebral cortex; (b) neuronal action potentials can provide the best picture of an intended action; (c) the best BCI is one that records action potentials and decodes them; and (d) ongoing mutual adaptation by the BCI user and the BCI system is not very important. In reality, none of these assumptions is presently defensible. Intended actions are the products of many areas, from the cortex to the spinal cord, and the contributions of each area change continually as the CNS adapts to optimize performance. BCIs must track and guide these adaptations if they are to achieve and maintain good performance. Furthermore, it is not yet clear which category of brain signals will prove most effective for BCI applications. In human studies to date, low-resolution electroencephalography-based BCIs perform as well as high-resolution cortical neuron-based BCIs. In sum, BCIs allow their users to develop new skills in which the users control brain signals rather than muscles. Thus, the central task of BCI research is to determine which brain signals users can best control, to maximize that control, and to translate it accurately and reliably into actions that accomplish the users' intentions.10abrain-computer interface10abrain-machine interface10aEEG10ahuman10aneuroprosthesis1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/2118435201419nas a2200181   4500008004100000022001400041245011600055210006900171260001200240300001000252490000600262520084000268653001601108100001801124700002601142700002101168856004801189       2010                        eng d  a1741-255200aA comparison of regression techniques for a two-dimensional sensorimotor rhythm-based brain-computer interface.0 acomparison of regression techniques for a twodimensional sensori  c02/2010  a160030 v73 aPeople can learn to control electroencephalogram (EEG) features consisting of sensorimotor-rhythm amplitudes and use this control to move a cursor in one, two or three dimensions to a target on a video screen. This study evaluated several possible alternative models for translating these EEG features into two-dimensional cursor movement by building an offline simulation using data collected during online performance. In offline comparisons, support-vector regression (SVM) with a radial basis kernel produced somewhat better performance than simple multiple regression, the LASSO or a linear SVM. These results indicate that proper choice of a translation algorithm is an important factor in optimizing brain-computer interface (BCI) performance, and provide new insight into algorithm choice for multidimensional movement control.10aYoung Adult1 aFruitet, Joan1 aMcFarland, Dennis, J.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/2007550302830nas a2200337   4500008004100000022001400041245004900055210004500104260001200149300001100161490000600172520196200178653001002140653003502150653001802185653001102203653001102214653000902225653001602234653002502250653002302275653002802298653001602326100001902342700001302361700001502374700002102389700001502410700001902425856004802444       2010                        eng d  a1741-255200aDoes the 'P300' speller depend on eye gaze?.0 aDoes the P300 speller depend on eye gaze  c10/2010  a0560130 v73 a<p><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">Many people affected by debilitating neuromuscular disorders such as amyotrophic lateral sclerosis, brainstem stroke or spinal cord injury are impaired in their ability to, or are even unable to, communicate. A brain-computer interface (BCI) uses brain signals, rather than muscles, to re-establish communication with the outside world. One particular BCI approach is the so-called 'P300 matrix speller' that was first described by Farwell and Donchin (1988 Electroencephalogr. Clin. Neurophysiol. 70 510-23). It has been widely assumed that this method does not depend on the ability to focus on the desired character, because it was thought that it relies primarily on the P300-evoked potential and minimally, if at all, on other EEG features such as the visual-evoked potential (VEP). This issue is highly relevant for the clinical application of this BCI method, because eye movements may be impaired or lost in the relevant user population. This study investigated the extent to which the performance in a 'P300' speller BCI depends on eye gaze. We evaluated the performance of 17 healthy subjects using a 'P300' matrix speller under two conditions. Under one condition ('letter'), the subjects focused their eye gaze on the intended letter, while under the second condition ('center'), the subjects focused their eye gaze on a fixation cross that was located in the center of the matrix. The results show that the performance of the 'P300' matrix speller in normal subjects depends in considerable measure on gaze direction. They thereby disprove a widespread assumption in BCI research, and suggest that this BCI might function more effectively for people who retain some eye-movement control. The applicability of these findings to people with severe neuromuscular disabilities (particularly in eye-movements) remains to be determined.</span></p>10aAdult10aEvent-Related Potentials, P30010aEye Movements10aFemale10aHumans10aMale10aMiddle Aged10aModels, Neurological10aPhotic Stimulation10aUser-Computer Interface10aYoung Adult1 aBrunner, Peter1 aJoshi, S1 aBriskin, S1 aWolpaw, Jonathan1 aBischof, H1 aSchalk, Gerwin  uhttp://www.ncbi.nlm.nih.gov/pubmed/2085892401515nas a2200181   4500008004100000022001400041245007300055210006900128260001200197300001100209490000600220520095800226653002801184100002601212700002601238700002101264856004801285       2010                        eng d  a1741-255200aElectroencephalographic (EEG) control of three-dimensional movement.0 aElectroencephalographic EEG control of threedimensional movement  c06/2010  a0360070 v73 aBrain-computer interfaces (BCIs) can use brain signals from the scalp (EEG), the cortical surface (ECoG), or within the cortex to restore movement control to people who are paralyzed. Like muscle-based skills, BCIs' use requires activity-dependent adaptations in the brain that maintain stable relationships between the person's intent and the signals that convey it. This study shows that humans can learn over a series of training sessions to use EEG for three-dimensional control. The responsible EEG features are focused topographically on the scalp and spectrally in specific frequency bands. People acquire simultaneous control of three independent signals (one for each dimension) and reach targets in a virtual three-dimensional space. Such BCI control in humans has not been reported previously. The results suggest that with further development noninvasive EEG-based BCIs might control the complex movements of robotic arms or neuroprostheses.10aUser-Computer Interface1 aMcFarland, Dennis, J.1 aSarnacki, William, A.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/2046069002531nas a2200205   4500008004100000022001400041245009300055210006900148260001200217300001600229490000800245520189500253653001202148100002302160700002302183700002902206700002102235700002102256856004802277       2010                        eng d  a1522-159800aExternal urethral sphincter motoneuron properties in adult female rats studied in vitro.0 aExternal urethral sphincter motoneuron properties in adult femal  c09/2010  a1286–13000 v1043 aThe external urethral sphincter (EUS) muscle plays a crucial role in lower urinary tract function: its activation helps maintain continence, whereas its relaxation contributes to micturition. To determine how the intrinsic properties of its motoneurons contribute to its physiological function, we have obtained intracellular current-clamp recordings from 49 EUS motoneurons in acutely isolated spinal cord slices from adult female rats. In all, 45% of EUS motoneurons fired spontaneously and steadily (average rate = 12-27 pulses/s). EUS motoneurons were highly excitable, having lower rheobase, higher input resistance, and smaller threshold depolarization than those of rat hindlimb motoneurons recorded in vitro. Correlations between these properties and afterhyperpolarization half-decay time are consistent with EUS motoneurons having characteristics of both fast and slow motor unit types. EUS motoneurons with a slow-like spectrum of properties exhibited spontaneous firing more often than those with fast-like characteristics. During triangular current ramp-induced repetitive firing, recruitment typically occurred at lower current levels than those at derecruitment, although the opposite pattern occurred in 10% of EUS motoneurons. This percentage was likely underestimated due to firing rate adaptation. These findings are consistent with the presence of a basal level of persistent inward current (PIC) in at least some EUS motoneurons. The low EUS motoneuron current and voltage thresholds make them readily recruitable, rendering them well suited to their physiological role in continence. The expression of firing behaviors consistent with PIC activation in this highly reduced preparation raises the possibility that in the intact animal, PICs contribute to urinary function not only through neuromodulator-dependent but also through neuromodulator-independent mechanisms.10aUrethra1 aCarp, Jonathan, S.1 aTennissen, Ann, M.1 aLiebschutz, Jennifer, E.1 aChen, Xiang Yang1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/2057397602599nas a2200289   4500008004100000022001400041245013200055210006900187260001200256300001800268490000700286520174900293653001702042653002102059653001502080653001102095653001702106653001602123100001302139700001302152700001302165700001702178700002402195700002102219700002102240856004802261       2010                        eng d  a1529-240100aH-reflex up-conditioning encourages recovery of EMG activity and H-reflexes after sciatic nerve transection and repair in rats.0 aHreflex upconditioning encourages recovery of EMG activity and H  c12/2010  a16128–161360 v303 aOperant conditioning of the spinal stretch reflex or its electrical analog, the H-reflex, produces spinal cord plasticity and can thereby affect motoneuron responses to primary afferent input. To explore whether this conditioning can affect the functional outcome after peripheral nerve injury, we assessed the effect of up-conditioning soleus (SOL) H-reflex on SOL and tibialis anterior (TA) function after sciatic nerve transection and repair. Sprague Dawley rats were implanted with EMG electrodes in SOL and TA and stimulating cuffs on the posterior tibial nerve. After control data collection, the sciatic nerve was transected and repaired and the rat was exposed for 120 d to continued control data collection (TC rats) or SOL H-reflex up-conditioning (TU rats). At the end of data collection, motoneurons that had reinnervated SOL and TA were labeled retrogradely. Putative primary afferent terminals [i.e., terminals containing vesicular glutamate transporter-1 (VGLUT1)] on SOL motoneurons were studied immunohistochemically. SOL (and probably TA) background EMG activity recovered faster in TU rats than in TC rats, and the final recovered SOL H-reflex was significantly larger in TU than in TC rats. TU and TC rats had significantly fewer labeled motoneurons and higher proportions of double-labeled motoneurons than untransected rats. VGLUT1 terminals were significantly more numerous on SOL motoneurons of TU than TC rats. Combined with the larger H-reflexes in TU rats, this anatomical finding supports the hypothesis that SOL H-reflex up-conditioning strengthened primary afferent reinnervation of SOL motoneurons. These results suggest that H-reflex up-conditioning may improve functional recovery after nerve injury and repair.10aconditioning10aperipheral nerve10aplasticity10aReflex10aregeneration10aSpinal Cord1 aChen, Yi1 aWang, Yu1 aChen, Lu1 aSun, Chenyou1 aEnglish, Arthur, W.1 aWolpaw, Jonathan1 aChen, Xiang Yang  uhttp://www.ncbi.nlm.nih.gov/pubmed/2112355902444nas a2200325   4500008004100000022001400041245011200055210006900167260001200236300001600248490000800264520147000272653002901742653002801771653000801799653002801807653000901835653001901844100001701863700002001880700002501900700002301925700001701948700001901965700002101984700002402005700002102029700002002050856004802070       2010                        eng d  a1872-895200aA novel P300-based brain-computer interface stimulus presentation paradigm: moving beyond rows and columns.0 anovel P300based braincomputer interface stimulus presentation pa  c07/2010  a1109–11200 v1213 aOBJECTIVE:
An electroencephalographic brain-computer interface (BCI) can provide a non-muscular means of communication for people with amyotrophic lateral sclerosis (ALS) or other neuromuscular disorders. We present a novel P300-based BCI stimulus presentation - the checkerboard paradigm (CBP). CBP performance is compared to that of the standard row/column paradigm (RCP) introduced by Farwell and Donchin (1988).
METHODS:
Using an 8x9 matrix of alphanumeric characters and keyboard commands, 18 participants used the CBP and RCP in counter-balanced fashion. With approximately 9-12 min of calibration data, we used a stepwise linear discriminant analysis for online classification of subsequent data.
RESULTS:
Mean online accuracy was significantly higher for the CBP, 92%, than for the RCP, 77%. Correcting for extra selections due to errors, mean bit rate was also significantly higher for the CBP, 23 bits/min, than for the RCP, 17 bits/min. Moreover, the two paradigms produced significantly different waveforms. Initial tests with three advanced ALS participants produced similar results. Furthermore, these individuals preferred the CBP to the RCP.
CONCLUSIONS:
These results suggest that the CBP is markedly superior to the RCP in performance and user acceptability.
SIGNIFICANCE:
The CBP has the potential to provide a substantially more effective BCI than the RCP. This is especially important for people with severe neuromuscular disabilities.10abrain-computer interface10abrain-machine interface10aEEG10aevent-related potential10aP30010aRehabilitation1 aTownsend, G.1 aLaPallo, B., K.1 aBoulay, Chadwick, B.1 aKrusienski, D., J.1 aFrye, G., E.1 aHauser, C., K.1 aSchwartz, N., E.1 aVaughan, Theresa, M1 aWolpaw, Jonathan1 aSellers, E., W.  uhttp://www.ncbi.nlm.nih.gov/pubmed/2034738701519nas a2200301   4500008004100000022001400041245009500055210006900150260001200219300001400231490001700245520064100262653001300903653002400916653001500940653001500955653002400970653001900994653002301013100002101036700001301057700001301070700001901083700002301102700002301125700002101148856004801169       2010                        eng d  a1749-663200aReflex conditioning: a new strategy for improving motor function after spinal cord injury.0 aReflex conditioning a new strategy for improving motor function   c06/2010  aE12–E210 v1198 Suppl 13 aSpinal reflex conditioning changes reflex size, induces spinal cord plasticity, and modifies locomotion. Appropriate reflex conditioning can improve walking in rats after spinal cord injury (SCI). Reflex conditioning offers a new therapeutic strategy for restoring function in people with SCI. This approach can address the specific deficits of individuals with SCI by targeting specific reflex pathways for increased or decreased responsiveness. In addition, once clinically significant regeneration can be achieved, reflex conditioning could provide a means of reeducating the newly (and probably imperfectly) reconnected spinal cord.10aH-Reflex10alearning and memory10aLocomotion10aplasticity10areflex conditioning10aRehabilitation10aspinal cord injury1 aChen, Xiang Yang1 aChen, Yi1 aWang, Yu1 aThompson, Aiko1 aCarp, Jonathan, S.1 aSegal, Richard, L.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/2059053401829nas a2200157   4500008004100000022001400041245006600055210006400121260001200185300001400197490000700211520136800218653001601586100002101602856004801623       2010                        eng d  a1089-409800aWhat can the spinal cord teach us about learning and memory?.0 aWhat can the spinal cord teach us about learning and memory  c10/2010  a532–5490 v163 aThe work of recent decades has shown that the nervous system changes continually throughout life. Activity-dependent central nervous system (CNS) plasticity has many different mechanisms and involves essentially every region, from the cortex to the spinal cord. This new knowledge radically changes the challenge of explaining learning and memory and greatly increases the relevance of the spinal cord. The challenge is now to explain how continual and ubiquitous plasticity accounts for the initial acquisition and subsequent stability of many different learned behaviors. The spinal cord has a key role because it is the final common pathway for all behavior and is a site of substantial plasticity. Furthermore, because it is simple, accessible, distant from the rest of the CNS, and directly connected to behavior, the spinal cord is uniquely suited for identifying sites and mechanisms of plasticity and for determining how they account for behavioral change. Experimental models based on spinal cord reflexes facilitate study of the gradual plasticity that makes possible most rapid learning phenomena. These models reveal principles and generate concepts that are likely to apply to learning and memory throughout the CNS. In addition, they offer new approaches to guiding activity-dependent plasticity so as to restore functions lost to injury or disease.10aSpinal Cord1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/2088996402476nas a2200241   4500008004100000022001400041245011900055210006900174260001200243300001600255490000700271520173900278653001302017653001902030653001602049653002502065653001502090653001602105100002302121700002102144700002102165856004802186       2009                        eng d  a1529-240100aAcquisition of a simple motor skill: task-dependent adaptation plus long-term change in the human soleus H-reflex.0 aAcquisition of a simple motor skill taskdependent adaptation plu  c05/2009  a5784–57920 v293 aActivity-dependent plasticity occurs throughout the CNS. However, investigations of skill acquisition usually focus on cortex. To expand the focus, we analyzed in humans the development of operantly conditioned H-reflex change, a simple motor skill that develops gradually and involves plasticity in both the brain and the spinal cord. Each person completed 6 baseline and 24 conditioning sessions over 10 weeks. In each conditioning session, the soleus H-reflex was measured while the subject was or was not asked to increase (HRup subjects) or decrease (HRdown subjects) it. When the subject was asked to change H-reflex size, immediate visual feedback indicated whether a size criterion had been satisfied. Over the 24 conditioning sessions, H-reflex size gradually increased in six of eight HRup subjects and decreased in eight of nine HRdown subjects, resulting in final sizes of 140 +/- 12 and 69 +/- 6% of baseline size, respectively. The final H-reflex change was the sum of within-session (i.e., task-dependent) adaptation and across-session (i.e., long-term) change. Task-dependent adaptation appeared within four to six sessions and persisted thereafter, averaging +13% in HRup subjects and -15% in HRdown subjects. In contrast, long-term change began after 10 sessions and increased gradually thereafter, reaching +27% in HRup subjects and -16% in HRdown subjects. Thus, the acquisition of H-reflex conditioning consists of two phenomena, task-dependent adaptation and long-term change, that together constitute the new motor skill. In combination with previous data, this new finding further elucidates the interaction of plasticity in brain and spinal cord that underlies the acquisition and maintenance of motor skills.10aH-Reflex10amotor learning10amotor skill10aoperant conditioning10aplasticity10aSpinal Cord1 aThompson, Aiko, K.1 aChen, Xiang Yang1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1942024601458nas a2200169   4500008004100000022001400041245011700055210006900172260001200241300001400253490000700267520089200274653002801166100002501194700002101219856004801240       2009                        eng d  a0074-774200aBrain-computer interface research at the wadsworth center developments in noninvasive communication and control.0 aBraincomputer interface research at the wadsworth center develop  c02/2009  a147–1570 v863 aBrain-computer interface (BCI) research at the Wadsworth Center focuses on noninvasive, electroencephalography (EEG)-based BCI methods for helping severely disabled individuals communicate and interact with their environment. We have demonstrated that these individuals, as well as able-bodied individuals, can learn to use sensorimotor rhythms (SMRs) to move a cursor rapidly and accurately in one and two dimensions. We have also developed a practical P300-based BCI that enables users to access and control the full functionality of their personal computer. We are currently translating this laboratory-proved BCI technology into a system that can be used by severely disabled individuals in their homes with minimal ongoing technical oversight. Our comprehensive approach to BCI design has led to several innovations that are applicable in other BCI contexts, such as space missions.10aUser-Computer Interface1 aKrusienski, Dean, J.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1960799701633nas a2200157   4500008004100000022001400041245009200055210006900147260000900216300001400225490000600239520114100245100002001386700002101406856004801427       2009                        eng d  a1941-118900aClinical Applications of Brain-Computer Interfaces: Current State and Future Prospects.0 aClinical Applications of BrainComputer Interfaces Current State   c2009  a187–1990 v23 aBrain-computer interfaces (BCIs) allow their users to communicate or control external devices using brain signals rather than the brain's normal output pathways of peripheral nerves and muscles. Motivated by the hope of restoring independence to severely disabled individuals and by interest in further extending human control of external systems, researchers from many fields are engaged in this challenging new work. BCI research and development have grown explosively over the past two decades. Efforts have recently begun to provide laboratory-validated BCI systems to severely disabled individuals for real-world applications. In this review, we discuss the current status and future prospects of BCI technology and its clinical applications. We will define BCI, review the BCI-relevant signals from the human brain, and describe the functional components of BCIs. We will also review current clinical applications of BCI technology, and identify potential users and potential applications. Finally, we will discuss current limitations of BCI technology, impediments to its widespread clinical use, and expectations for the future.1 aMak, Joseph, N.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/2044280402146nas a2200397   4500008004100000022001400041245009000055210006900145260001200214300001100226490000600237520112800243653001501371653001001386653001701396653001001413653002101423653001301444653001101457653001201468653001101480653000901491653002001500653001601520653001901536653000901555653001001564653001701574653001601591100001601607700002001623700001701643700002101660700001901681856004801700       2009                        eng d  a1741-255200aDecoding flexion of individual fingers using electrocorticographic signals in humans.0 aDecoding flexion of individual fingers using electrocorticograph  c12/2009  a0660010 v63 a<p><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">Brain signals can provide the basis for a non-muscular communication and control system, a brain-computer interface (BCI), for people with motor disabilities. A common approach to creating BCI devices is to decode kinematic parameters of movements using signals recorded by intracortical microelectrodes. Recent studies have shown that kinematic parameters of hand movements can also be accurately decoded from signals recorded by electrodes placed on the surface of the brain (electrocorticography (ECoG)). In the present study, we extend these results by demonstrating that it is also possible to decode the time course of the flexion of individual fingers using ECoG signals in humans, and by showing that these flexion time courses are highly specific to the moving finger. These results provide additional support for the hypothesis that ECoG could be the basis for powerful clinically practical BCI systems, and also indicate that ECoG is useful for studying cortical dynamics related to motor function.</span></p>10aAdolescent10aAdult10aBiomechanics10aBrain10aElectrodiagnosis10aEpilepsy10aFemale10aFingers10aHumans10aMale10aMicroelectrodes10aMiddle Aged10aMotor Activity10aRest10aThumb10aTime Factors10aYoung Adult1 aKubánek, J1 aMiller, John, W1 aOjemann, J G1 aWolpaw, Jonathan1 aSchalk, Gerwin  uhttp://www.ncbi.nlm.nih.gov/pubmed/1979423701505nas a2200253   4500008004100000022001400041245012000055210006900175260001200244300001400256490000800270520070300278653003400981653002701015653002601042653002401068653001801092653001601110100001301126700002201139700002101161700002101182856004801203       2009                        eng d  a0304-394000aH-reflex down-conditioning greatly increases the number of identifiable GABAergic interneurons in rat ventral horn.0 aHreflex downconditioning greatly increases the number of identif  c03/2009  a124–1290 v4523 aH-reflex down-conditioning increases GABAergic terminals on spinal cord motoneurons. To explore the origins of these terminals, we studied the numbers and distributions of spinal cord GABAergic interneurons. The number of identifiable GABAergic interneurons in the ventral horn was 78% greater in rats in which down-conditioning was successful than in naive rats or rats in which down-conditioning failed. No increase occurred in other spinal lamina or on the contralateral side. This finding supports the hypothesis that the corticospinal tract influence that induces the motoneuron plasticity underlying down-conditioning reaches the motoneuron through GABAergic interneurons in the ventral horn.10aactivity-dependent plasticity10aGABAergic interneurons10aH-reflex conditioning10alearning and memory10aMotor control10aSpinal Cord1 aWang, Yu1 aPillai, Shreejith1 aWolpaw, Jonathan1 aChen, Xiang Yang  uhttp://www.ncbi.nlm.nih.gov/pubmed/1938342601741nas a2200253   4500008004100000022001400041245008200055210006900137260001200206300001400218490000700232520097500239653000801214653002901222653002201251653002401273100003201297700002601329700002001355700002401375700001901399700002101418856004801439       2009                        eng d  a1873-624600aA scanning protocol for a sensorimotor rhythm-based brain-computer interface.0 ascanning protocol for a sensorimotor rhythmbased braincomputer i  c02/2009  a169–1750 v803 aThe scanning protocol is a novel brain-computer interface (BCI) implementation that can be controlled with sensorimotor rhythms (SMRs) of the electroencephalogram (EEG). The user views a screen that shows four choices in a linear array with one marked as target. The four choices are successively highlighted for 2.5s each. When a target is highlighted, the user can select it by modulating the SMR. An advantage of this method is the capacity to choose among multiple choices with just one learned SMR modulation. Each of 10 naive users trained for ten 30 min sessions over 5 weeks. User performance improved significantly (p<0.001) over the sessions and ranged from 30 to 80% mean accuracy of the last three sessions (chance accuracy=25%). The incidence of correct selections depended on the target position. These results suggest that, with further improvements, a scanning protocol can be effective. The ultimate goal is to expand it to a large matrix of selections.10aBCI10abrain-computer interface10ascanning protocol10asensorimotor rhythm1 aFriedrich, Elisabeth, V. C.1 aMcFarland, Dennis, J.1 aNeuper, Christa1 aVaughan, Theresa, M1 aBrunner, Peter1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1878660302473nas a2200289   4500008004100000022001400041245007500055210006900130260001200199300001600211490000800227520163800235653002901873653002801902653000801930653002801938653000901966653001901975100002101994700002402015700001902039700002102058700002102079700001502100700002002115856004802135       2009                        eng d  a1872-895200aToward a high-throughput auditory P300-based brain-computer interface.0 aToward a highthroughput auditory P300based braincomputer interfa  c07/2009  a1252–12610 v1203 aOBJECTIVE:
Brain-computer interface (BCI) technology can provide severely disabled people with non-muscular communication. For those most severely disabled, limitations in eye mobility or visual acuity may necessitate auditory BCI systems. The present study investigates the efficacy of the use of six environmental sounds to operate a 6x6 P300 Speller.
METHODS:
A two-group design was used to ascertain whether participants benefited from visual cues early in training. Group A (N=5) received only auditory stimuli during all 11 sessions, whereas Group AV (N=5) received simultaneous auditory and visual stimuli in initial sessions after which the visual stimuli were systematically removed. Stepwise linear discriminant analysis determined the matrix item that elicited the largest P300 response and thereby identified the desired choice.
RESULTS:
Online results and offline analyses showed that the two groups achieved equivalent accuracy. In the last session, eight of 10 participants achieved 50% or more, and four of these achieved 75% or more, online accuracy (2.8% accuracy expected by chance). Mean bit rates averaged about 2 bits/min, and maximum bit rates reached 5.6 bits/min.
CONCLUSIONS:
This study indicates that an auditory P300 BCI is feasible, that reasonable classification accuracy and rate of communication are achievable, and that the paradigm should be further evaluated with a group of severely disabled participants who have limited visual mobility.
SIGNIFICANCE:
With further development, this auditory P300 BCI could be of substantial value to severely disabled people who cannot use a visual BCI.10abrain-computer interface10abrain-machine interface10aEEG10aevent-related potential10aP30010aRehabilitation1 aKlobassa, D., S.1 aVaughan, Theresa, M1 aBrunner, Peter1 aSchwartz, N., E.1 aWolpaw, Jonathan1 aNeuper, C.1 aSellers, E., W.  uhttp://www.ncbi.nlm.nih.gov/pubmed/1957409105137nas a2200373   4500008004100000022001400041245007500055210006900130260001200199300001000211490000800221520406800229653001004297653001504307653001004322653001804332653002404350653002704374653001104401653000904412653002404421653002404445653001904469653003604488653004104524653002404565653002804589100001904617700001904636700002404655700001504679700002104694856004804715       2008                        eng d  a0165-027000aBrain-computer interfaces (BCIs): Detection Instead of Classification.0 aBraincomputer interfaces BCIs Detection Instead of Classificatio  c01/2008  a51-620 v1673 a<p><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">Many studies over the past two decades have shown that people can use&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">brain</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;signals to convey their intent to a&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">computer</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;through&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">brain-computer interfaces</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;(BCIs). These devices operate by recording signals from the&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">brain</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;and translating these signals into device commands. They can be used by people who are severely paralyzed to communicate without any use of muscle activity. One of the major impediments in translating this novel technology into&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">clinical</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;applications is the current requirement for preliminary analyses to identify the&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">brain</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;signal features best suited for communication. This paper introduces and validates signal detection, which does not require such analysis procedures, as a new concept in BCI signal processing. This detection concept is realized with Gaussian mixture models (GMMs) that are used to model resting&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">brain</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;activity so that any change in&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">relevant</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">brain</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;signals can be detected. It is implemented in a package called SIGFRIED (SIGnal modeling For Real-time Identification and Event Detection). The results indicate that SIGFRIED produces results that are within the range of those achieved using a common analysis strategy that requires preliminary identification of signal features. They indicate that such laborious analysis procedures could be replaced by merely recording&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">brain</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;signals during rest. In summary, this paper demonstrates how SIGFRIED could be used to overcome one of the present impediments to translation of laboratory BCI demonstrations into clinically practical applications.</span></p>10aAdult10aAlgorithms10aBrain10aBrain Mapping10aElectrocardiography10aElectroencephalography10aHumans10aMale10aMan-Machine Systems10aNormal Distribution10aOnline Systems10aSignal Detection, Psychological10aSignal Processing, Computer-Assisted10aSoftware Validation10aUser-Computer Interface1 aSchalk, Gerwin1 aBrunner, Peter1 aGerhardt, Lester, A1 aBischof, H1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1792013401806nas a2200169   4500008004100000022001400041245006200055210006000117260001200177300001600189490000600205520130800211653002801519100002001547700002101567856004801588       2008                        eng d  a1474-442200aBrain-computer interfaces in neurological rehabilitation.0 aBraincomputer interfaces in neurological rehabilitation  c11/2008  a1032–10430 v73 aRecent advances in analysis of brain signals, training patients to control these signals, and improved computing capabilities have enabled people with severe motor disabilities to use their brain signals for communication and control of objects in their environment, thereby bypassing their impaired neuromuscular system. Non-invasive, electroencephalogram (EEG)-based brain-computer interface (BCI) technologies can be used to control a computer cursor or a limb orthosis, for word processing and accessing the internet, and for other functions such as environmental control or entertainment. By re-establishing some independence, BCI technologies can substantially improve the lives of people with devastating neurological disorders such as advanced amyotrophic lateral sclerosis. BCI technology might also restore more effective motor control to people after stroke or other traumatic brain disorders by helping to guide activity-dependent brain plasticity by use of EEG brain signals to indicate to the patient the current state of brain activity and to enable the user to subsequently lower abnormal activity. Alternatively, by use of brain signals to supplement impaired muscle control, BCIs might increase the efficacy of a rehabilitation protocol and thus improve muscle control for the patient.10aUser-Computer Interface1 aDaly, Janis, J.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1883554102704nas a2200241   4500008004100000022001400041245009000055210006900145260001200214300001400226490000700240520199800247653003402245653001302279653001102292653001802303653001602321100002202337700001302359700002102372700002102393856004802414       2008                        eng d  a1460-956800aEffects of H-reflex up-conditioning on GABAergic terminals on rat soleus motoneurons.0 aEffects of Hreflex upconditioning on GABAergic terminals on rat   c08/2008  a668–6740 v283 aTo explore the role of spinal cord plasticity in motor learning, we evaluated the effects of H-reflex operant conditioning on GABAergic input to rat spinal motoneurons. Previous work indicated that down-conditioning of soleus H-reflex increases GABAergic input to soleus motoneurons. This study explored the effect of H-reflex up-conditioning on GABAergic input. Of nine rats exposed to H-reflex up-conditioning, up-conditioning was successful (H-reflex increase >or= 20%) in seven and failed (change < 20%) in two. These rats and eight naive control (i.e. unconditioned) rats were injected with cholera toxin subunit B-conjugated Alexa fluor 488 into the soleus muscle to retrogradely label soleus motoneurons. Sections containing soleus motoneurons were processed for GAD(67) [one of the two principal forms of the GABA-synthesizing enzyme glutamic acid decarboxylase (GAD)] with an ABC-peroxidase system. Two blinded independent raters counted and measured GABAergic terminals on these motoneurons. Unlike successful down-conditioning, which greatly increased the number of identifiable GABAergic terminals on the motoneurons, up-conditioning did not significantly change GABAergic terminal number. Successful up-conditioning did produce slight but statistically significant increases in GABAergic terminal diameter and soma coverage. These results are consistent with other data indicating that up- and down-conditioning are not mirror images of each other, but rather have different mechanisms. Although the marked changes in GABAergic terminals with down-conditioning probably contribute to H-reflex decrease, the modest changes in GABAergic terminals associated with up-conditioning may be compensatory or reactive plasticity, rather than the plasticity responsible for H-reflex increase. As a variety of spinal and supraspinal GABAergic neurons innervate motoneurons, the changes found with up-conditioning may be in terminals other than those affected in successful down-conditioning.10aactivity-dependent plasticity10aLearning10aMemory10aMotor control10aSpinal Cord1 aPillai, Shreejith1 aWang, Yu1 aWolpaw, Jonathan1 aChen, Xiang Yang  uhttp://www.ncbi.nlm.nih.gov/pubmed/1865718401945nas a2200193   4500008004100000022001400041245008500055210006900140260001200209300001400221490000600235520133600241653002801577100002601605700002501631700002601656700002101682856004801703       2008                        eng d  a1741-256000aEmulation of computer mouse control with a noninvasive brain-computer interface.0 aEmulation of computer mouse control with a noninvasive braincomp  c06/2008  a101–1100 v53 aBrain-computer interface (BCI) technology can provide nonmuscular communication and control to people who are severely paralyzed. BCIs can use noninvasive or invasive techniques for recording the brain signals that convey the user's commands. Although noninvasive BCIs are used for simple applications, it has frequently been assumed that only invasive BCIs, which use electrodes implanted in the brain, will be able to provide multidimensional sequential control of a robotic arm or a neuroprosthesis. The present study shows that a noninvasive BCI using scalp-recorded electroencephalographic (EEG) activity and an adaptive algorithm can provide people, including people with spinal cord injuries, with two-dimensional cursor movement and target selection. Multiple targets were presented around the periphery of a computer screen, with one designated as the correct target. The user's task was to use EEG to move a cursor from the center of the screen to the correct target and then to use an additional EEG feature to select the target. If the cursor reached an incorrect target, the user was instructed not to select it. Thus, this task emulated the key features of mouse operation. The results indicate that people with severe motor disabilities could use brain signals for sequential multidimensional movement and selection.10aUser-Computer Interface1 aMcFarland, Dennis, J.1 aKrusienski, Dean, J.1 aSarnacki, William, A.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1836777902323nas a2200217   4500008004100000022001400041245007800055210006900133260001200202300001400214490000800228520164900236653003201885100002301917700002301940700002501963700002701988700002102015700002102036856004802057       2008                        eng d  a0022-307700aAn in vitro protocol for recording from spinal motoneurons of adult rats.0 ain vitro protocol for recording from spinal motoneurons of adult  c07/2008  a474–4810 v1003 aIn vitro slice preparations of CNS tissue are invaluable for studying neuronal function. However, up to now, slice protocols for adult mammal spinal motoneurons–the final common pathway for motor behaviors–have been available for only limited portions of the spinal cord. In most cases, these preparations have not been productive due to the poor viability of motoneurons in vitro. This report describes and validates a new slice protocol that for the first time provides reliable intracellular recordings from lumbar motoneurons of adult rats. The key features of this protocol are: preexposure to 100% oxygen; laminectomy prior to perfusion; anesthesia with ketamine/xylazine; embedding the spinal cord in agar prior to slicing; and, most important, brief incubation of spinal cord slices in a 30% solution of polyethylene glycol to promote resealing of the many motoneuron dendrites cut during sectioning. Together, these new features produce successful recordings in 76% of the experiments and an average action potential amplitude of 76 mV. Motoneuron properties measured in this new slice preparation (i.e., voltage and current thresholds for action potential initiation, input resistance, afterhyperpolarization size and duration, and onset and offset firing rates during current ramps) are comparable to those recorded in vivo. Given the mechanical stability and precise control over the extracellular environment afforded by an in vitro preparation, this new protocol can greatly facilitate electrophysiological and pharmacological study of these uniquely important neurons and other delicate neuronal populations in adult mammals.10aTissue and Organ Harvesting1 aCarp, Jonathan, S.1 aTennissen, Ann, M.1 aMongeluzi, Donna, L.1 aDudek, Christopher, J.1 aChen, Xiang Yang1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1846317702392nas a2200361   4500008004100000022001400041245008900055210006900144260001200213300001600225490000800241520135100249653003401600653002901634653002501663653002901688653000901717653001901726100001601745700002001761700001701781700001901798700001301817700001901830700001401849700001501863700002301878700002401901700002101925700002101946700001501967856004801982       2008                        eng d  a1388-245700aA P300-based brain-computer interface for people with amyotrophic lateral sclerosis.0 aP300based braincomputer interface for people with amyotrophic la  c08/2008  a1909–19160 v1193 aOBJECTIVE:
The current study evaluates the efficacy of a P300-based brain-computer interface (BCI) communication device for individuals with advanced ALS.
METHODS:
Participants attended to one cell of a N x N matrix while the N rows and N columns flashed randomly. Each cell of the matrix contained one character. Every flash of an attended character served as a rare event in an oddball sequence and elicited a P300 response. Classification coefficients derived using a stepwise linear discriminant function were applied to the data after each set of flashes. The character receiving the highest discriminant score was presented as feedback.
RESULTS:
In Phase I, six participants used a 6 x 6 matrix on 12 separate days with a mean rate of 1.2 selections/min and mean online and offline accuracies of 62% and 82%, respectively. In Phase II, four participants used either a 6 x 6 or a 7 x 7 matrix to produce novel and spontaneous statements with a mean online rate of 2.1 selections/min and online accuracy of 79%. The amplitude and latency of the P300 remained stable over 40 weeks.
CONCLUSIONS:
Participants could communicate with the P300-based BCI and performance was stable over many months.
SIGNIFICANCE:
BCIs could provide an alternative communication and control technology in the daily lives of people severely disabled by ALS.10aAmyotrophic Lateral Sclerosis10abrain-computer interface10aelectroencephalogram10aevent-related potentials10aP30010aRehabilitation1 aNijboer, F.1 aSellers, E., W.1 aMellinger, J1 aJordan, M., A.1 aMatuz, T1 aFurdea, Adrian1 aHalder, S1 aMochty, U.1 aKrusienski, D., J.1 aVaughan, Theresa, M1 aWolpaw, Jonathan1 aBirbaumer, Niels1 aKübler, A  uhttp://www.ncbi.nlm.nih.gov/pubmed/1857198403145nas a2200373   4500008004100000022001400041245005700055210005400112260001200166300001000178490000700188520212100195653001002316653001502326653001802341653002102359653003302380653002702413653001302440653002202453653001102475653001102486653000902497653003502506653003102541653003202572100001902604700001902623700001902642700001702661700002402678700002102702856004802723       2008                        eng d  a1095-957200aReal-time detection of event-related brain activity.0 aRealtime detection of eventrelated brain activity  c11/2008  a245-90 v433 a<p><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">The complexity and inter-individual variation of&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">brain</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;signals impedes real-time detection of events in raw signals. To convert these complex signals into results that can be readily understood, current approaches usually apply statistical methods to data from known conditions after all data have been collected. The capability to provide meaningful visualization of complex&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">brain</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;signals without the requirement to initially collect data from all conditions would provide a new tool, essentially a new imaging technique, that would open up new avenues for the study of&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">brain</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;function. Here we show that a new analysis approach, called SIGFRIED, can overcome this serious limitation of current methods. SIGFRIED can visualize&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">brain</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;signal changes without requiring prior data collection from all conditions. This capacity is particularly well suited to applications in which comprehensive prior data collection is impossible or impractical, such as intraoperative localization of cortical function or detection of epileptic seizures.</span></p>10aAdult10aAlgorithms10aBrain Mapping10aComputer Systems10aDiagnosis, Computer-Assisted10aElectroencephalography10aEpilepsy10aEvoked Potentials10aFemale10aHumans10aMale10aPattern Recognition, Automated10aReproducibility of Results10aSensitivity and Specificity1 aSchalk, Gerwin1 aLeuthardt, E C1 aBrunner, Peter1 aOjemann, J G1 aGerhardt, Lester, A1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1871854401908nas a2200169   4500008004100000022001400041245012200055210006900177260001200246300001400258490000600272520133700278653002801615100002601643700002101669856004801690       2008                        eng d  a1741-256000aSensorimotor rhythm-based brain-computer interface (BCI): model order selection for autoregressive spectral analysis.0 aSensorimotor rhythmbased braincomputer interface BCI model order  c06/2008  a155–1620 v53 aPeople can learn to control EEG features consisting of sensorimotor rhythm amplitudes and can use this control to move a cursor in one or two dimensions to a target on a screen. Cursor movement depends on the estimate of the amplitudes of sensorimotor rhythms. Autoregressive models are often used to provide these estimates. The order of the autoregressive model has varied widely among studies. Through analyses of both simulated and actual EEG data, the present study examines the effects of model order on sensorimotor rhythm measurements and BCI performance. The results show that resolution of lower frequency signals requires higher model orders and that this requirement reflects the temporal span of the model coefficients. This is true for both simulated EEG data and actual EEG data during brain-computer interface (BCI) operation. Increasing model order, and decimating the signal were similarly effective in increasing spectral resolution. Furthermore, for BCI control of two-dimensional cursor movement, higher model orders produced better performance in each dimension and greater independence between horizontal and vertical movements. In sum, these results show that autoregressive model order selection is an important determinant of BCI performance and should be based on criteria that reflect system performance.10aUser-Computer Interface1 aMcFarland, Dennis, J.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1843097401649nas a2200241   4500008004100000022001400041245004600055210004500101260001200146300001200158490000800170520095000178653002901128653002901157653001701186653004201203100002301245700002001268700002601288700002401314700002101338856004801359       2008                        eng d  a0165-027000aToward enhanced P300 speller performance.0 aToward enhanced P300 speller performance  c01/2008  a15–210 v1673 aThis study examines the effects of expanding the classical P300 feature space on the classification performance of data collected from a P300 speller paradigm [Farwell LA, Donchin E. Talking off the top of your head: toward a mental prosthesis utilizing event-related brain potentials. Electroenceph Clin Neurophysiol 1988;70:510-23]. Using stepwise linear discriminant analysis (SWLDA) to construct a classifier, the effects of spatial channel selection, channel referencing, data decimation, and maximum number of model features are compared with the intent of establishing a baseline not only for the SWLDA classifier, but for related P300 speller classification methods in general. By supplementing the classical P300 recording locations with posterior locations, online classification performance of P300 speller responses can be significantly improved using SWLDA and the favorable parameters derived from the offline comparative analysis.10abrain-computer interface10aevent related potentials10aP300 speller10astepwise linear discriminant analysis1 aKrusienski, D., J.1 aSellers, E., W.1 aMcFarland, Dennis, J.1 aVaughan, Theresa, M1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1782277704357nas a2200385   4500008004100000022001400041245009700055210006900152260001200221300001200233490000800245520323100253653001503484653001003499653001403509653001003523653001803533653004203551653002703593653003003620653001103650653001103661653000903672653003203681653002303713653002203736653002803758100002503786700002603811700001903837700002003856700002603876700002103902856004803923       2008                        eng d  a1388-245700aTowards an independent brain-computer interface using steady state visual evoked potentials.0 aTowards an independent braincomputer interface using steady stat  c02/2008  a399-4080 v1193 a<h4 style="font-size: 13px; margin: 0px 0.25em 0px 0px; text-transform: uppercase; float: left; font-family: arial, helvetica, clean, sans-serif; line-height: 17px;">OBJECTIVE:&nbsp;</h4>
<p style="margin: 0px 0px 0.5em; font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">Brain-computer interface (BCI) systems using steady state visual evoked potentials (SSVEPs) have allowed healthy subjects to communicate. However, these systems may not work in severely disabled users because they may depend on gaze shifting. This study evaluates the hypothesis that overlapping stimuli can evoke changes in SSVEP activity sufficient to control a BCI. This would provide evidence that SSVEP BCIs could be used without shifting gaze.</p>
<h4 style="font-size: 13px; margin: 0px 0.25em 0px 0px; text-transform: uppercase; float: left; font-family: arial, helvetica, clean, sans-serif; line-height: 17px;">METHODS:&nbsp;</h4>
<p style="margin: 0px 0px 0.5em; font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">Subjects viewed a display containing two images that each oscillated at a different frequency. Different conditions used overlapping or non-overlapping images to explore dependence on gaze function. Subjects were asked to direct attention to one or the other of these images during each of 12 one-minute runs.</p>
<h4 style="font-size: 13px; margin: 0px 0.25em 0px 0px; text-transform: uppercase; float: left; font-family: arial, helvetica, clean, sans-serif; line-height: 17px;">RESULTS:&nbsp;</h4>
<p style="margin: 0px 0px 0.5em; font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">Half of the subjects produced differences in SSVEP activity elicited by overlapping stimuli that could support BCI control. In all remaining users, differences did exist at corresponding frequencies but were not strong enough to allow effective control.</p>
<h4 style="font-size: 13px; margin: 0px 0.25em 0px 0px; text-transform: uppercase; float: left; font-family: arial, helvetica, clean, sans-serif; line-height: 17px;">CONCLUSIONS:&nbsp;</h4>
<p style="margin: 0px 0px 0.5em; font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">The&nbsp;<span class="highlight">data</span>&nbsp;demonstrate that SSVEP differences sufficient for BCI control may be elicited by selective attention to one of two overlapping stimuli. Thus, some SSVEP-based BCI approaches may not depend on gaze control. The nature and extent of any BCI's dependence on muscle activity is a function of many factors, including the display, task, environment, and user.</p>
<h4 style="font-size: 13px; margin: 0px 0.25em 0px 0px; text-transform: uppercase; float: left; font-family: arial, helvetica, clean, sans-serif; line-height: 17px;">SIGNIFICANCE:&nbsp;</h4>
<p style="margin: 0px 0px 0.5em; font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">SSVEP BCIs might function in severely disabled users unable to reliably control gaze. Further research with these users is necessary to explore the optimal parameters of such a system and validate online performance in a home environment.</p>10aAdolescent10aAdult10aAttention10aBrain10aBrain Mapping10aDose-Response Relationship, Radiation10aElectroencephalography10aEvoked Potentials, Visual10aFemale10aHumans10aMale10aPattern Recognition, Visual10aPhotic Stimulation10aSpectrum Analysis10aUser-Computer Interface1 aAllison, Brendan, Z.1 aMcFarland, Dennis, J.1 aSchalk, Gerwin1 aZheng, Shi Dong1 aMoore-Jackson, Melody1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1807720802662nas a2200409   4500008004100000022001400041245008400055210006900139260001200208300001000220490000600230520153900236653001501775653001001790653001801800653003701818653002001855653002401875653002601899653002701925653001301952653001101965653001101976653000901987653001301996653002802009100001902037700001602056700002602072700002002098700001602118700001702134700001302151700002102164700001902185856004802204       2008                        eng d  a1741-256000aTwo-dimensional movement control using electrocorticographic signals in humans.0 aTwodimensional movement control using electrocorticographic sign  c03/2008  a75-840 v53 a<p><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">We show here that a&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">brain-computer</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;interface (BCI) using electrocorticographic activity (ECoG) and imagined or overt motor tasks enables humans to control a&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">computer</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;cursor in two dimensions. Over a brief training period of 12-36 min, each of five human subjects acquired substantial control of particular ECoG features recorded from several locations over the same hemisphere, and achieved average success rates of 53-73% in a two-dimensional four-target center-out task in which chance accuracy was 25%. Our results support the expectation that ECoG-based BCIs can combine high performance with technical and&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">clinical</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;practicality, and also indicate promising directions for further research.</span></p>10aAdolescent10aAdult10aBrain Mapping10aData Interpretation, Statistical10aDrug Resistance10aElectrocardiography10aElectrodes, Implanted10aElectroencephalography10aEpilepsy10aFemale10aHumans10aMale10aMovement10aUser-Computer Interface1 aSchalk, Gerwin1 aMiller, K J1 aAnderson, Nicholas, R1 aWilson, Adam, J1 aSmyth, Matt1 aOjemann, J G1 aMoran, D1 aWolpaw, Jonathan1 aLeuthardt, E C  uhttp://www.ncbi.nlm.nih.gov/pubmed/1831081301471nas a2200325   4500008004100000022001400041245006200055210005900117260001200176300001400188490000600202520059000208653000800798653002800806653000800834653000800842653002600850653002900876653002800905653000800933653000800941653002300949653002800972653001001000653001101010100002501021700003001046700002101076856004801097       2007                        eng d  a1743-444000aBrain-computer interface systems: progress and prospects.0 aBraincomputer interface systems progress and prospects  c07/2007  a463–4740 v43 aBrain-computer interface (BCI) systems support communication through direct measures of neural activity without muscle activity. BCIs may provide the best and sometimes the only communication option for users disabled by the most severe neuromuscular disorders and may eventually become useful to less severely disabled and/or healthy individuals across a wide range of applications. This review discusses the structure and functions of BCI systems, clarifies terminology and addresses practical applications. Progress and opportunities in the field are also identified and explicated.10aALS10aassistive communication10aBCI10aBMI10abrain-acuated control10abrain-computer interface10abrain-machine interface10aEEG10aERP10alocked-in syndrome10aslow cortical potential10aSSVEP10aStroke1 aAllison, Brendan, Z.1 aWolpaw, Elizabeth, Winter1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1760568202957nas a2200157   4500008004100000022001400041245006000055210005800115260001200173300001400185490000800199520249500207653002802702100002102730856004802751       2007                        eng d  a0022-375100aBrain-computer interfaces as new brain output pathways.0 aBraincomputer interfaces as new brain output pathways  c03/2007  a613–6190 v5793 aBrain-computer interfaces (BCIs) can provide non-muscular communication and control for people with severe motor disabilities. Current BCIs use a variety of invasive and non-invasive methods to record brain signals and a variety of signal processing methods. Whatever the recording and processing methods used, BCI performance (e.g. the ability of a BCI to control movement of a computer cursor) is highly variable and, by the standards applied to neuromuscular control, could be described as ataxic. In an effort to understand this imperfection, this paper discusses the relevance of two principles that underlie the brain's normal motor outputs. The first principle is that motor outputs are normally produced by the combined activity of many CNS areas, from the cortex to the spinal cord. Together, these areas produce appropriate control of the spinal motoneurons that activate muscles. The second principle is that the acquisition and life-long preservation of motor skills depends on continual adaptive plasticity throughout the CNS. This plasticity optimizes the control of spinal motoneurons. In the light of these two principles, a BCI may be viewed as a system that changes the outcome of CNS activity from control of spinal motoneurons to, instead, control of the cortical (or other) area whose signals are used by the BCI to determine the user's intent. In essence, a BCI attempts to assign to cortical neurons the role normally performed by spinal motoneurons. Thus, a BCI requires that the many CNS areas involved in producing normal motor actions change their roles so as to optimize the control of cortical neurons rather than spinal motoneurons. The disconcerting variability of BCI performance may stem in large part from the challenge presented by the need for this unnatural adaptation. This difficulty might be reduced, and BCI development might thereby benefit, by adopting a 'goal-selection' rather than a 'process- control' strategy. In 'process control', a BCI manages all the intricate high-speed interactions involved in movement. In 'goal selection', by contrast, the BCI simply communicates the user's goal to software that handles the high-speed interactions needed to achieve the goal. Not only is 'goal selection' less demanding, but also, by delegating lower-level aspects of motor control to another structure (rather than requiring that the cortex do everything), it more closely resembles the distributed operation characteristic of normal motor control.10aUser-Computer Interface1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1725516402357nas a2200385   4500008004100000022001400041245009800055210006900153260001200222300001100234490000600245520131000251653001001561653001501571653000801586653001801594653002001612653002701632653002901659653001101688653001101699653000901710653001301719100001901732700001601751700002001767700002601787700001901813700001701832700001601849700001301865700002401878700002101902856004801923       2007                        eng d  a1741-256000aDecoding two-dimensional movement trajectories using electrocorticographic signals in humans.0 aDecoding twodimensional movement trajectories using electrocorti  c09/2007  a264-750 v43 a<p><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">Signals from the brain could provide a non-muscular communication and control system, a brain-computer interface (BCI), for people who are severely paralyzed. A common BCI research strategy begins by decoding kinematic parameters from brain signals recorded during actual arm movement. It has been assumed that these parameters can be derived accurately only from signals recorded by intracortical microelectrodes, but the long-term stability of such electrodes is uncertain. The present study disproves this widespread assumption by showing in humans that kinematic parameters can also be decoded from signals recorded by subdural electrodes on the cortical surface (ECoG) with an accuracy comparable to that achieved in monkey studies using intracortical microelectrodes. A new ECoG feature labeled the local motor potential (LMP) provided the most information about movement. Furthermore, features displayed cosine tuning that has previously been described only for signals recorded within the brain. These results suggest that ECoG could be a more stable and less invasive alternative to intracortical electrodes for BCI systems, and could also prove useful in studies of motor function.</span></p>10aAdult10aAlgorithms10aArm10aBrain Mapping10aCerebral Cortex10aElectroencephalography10aEvoked Potentials, Motor10aFemale10aHumans10aMale10aMovement1 aSchalk, Gerwin1 aKubánek, J1 aMiller, John, W1 aAnderson, Nicholas, R1 aLeuthardt, E C1 aOjemann, J G1 aLimbrick, D1 aMoran, D1 aGerhardt, Lester, A1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1787342902087nas a2200205   4500008004100000022001400041245010700055210006900162260001200231300001600243490000700259520144800266653001701714100002401731700001301755700002301768700002101791700002101812856004801833       2007                        eng d  a0022-307700aRecovery of electromyographic activity after transection and surgical repair of the rat sciatic nerve.0 aRecovery of electromyographic activity after transection and sur  c02/2007  a1127–11340 v973 aThe recovery of soleus (SOL), gastrocnemius (GAS), and tibialis anterior (TA) electromyographic activity (EMG) after transection and surgical repair of the sciatic nerve was studied in Sprague-Dawley rats using chronically implanted stimulation and recording electrodes. Spontaneous EMG activity in SOL and GAS and direct muscle (M) responses to posterior tibial nerve stimulation persisted for < or =2 days after sciatic nerve transection, but SOL and GAS H-reflexes disappeared immediately. Spontaneous EMG activity began to return 2-3 wk after transection, rose nearly to pretransection levels by 60 days, and persisted for the duration of the study period (120 days). Recovery of stimulus-evoked EMG responses began about 30 days after sciatic nerve transection as multiple small responses with a wide range of latencies. Over time, the latencies of these fractionated responses shortened, their amplitudes increased, and they merged into a distinct short-latency component (the putative M response) and a distinct long-latency component (the putative H-reflex). The extent of recovery of stimulation-evoked EMG was modest: even 100 days after sciatic nerve transection, the responses were still much smaller than those before transection. Similar gradual development of responses to posterior tibial nerve stimulation was also seen in TA, suggesting that some regenerating fibers sent branches into both tibial and common peroneal nerves.10aTibial Nerve1 aEnglish, Arthur, W.1 aChen, Yi1 aCarp, Jonathan, S.1 aWolpaw, Jonathan1 aChen, Xiang Yang  uhttp://www.ncbi.nlm.nih.gov/pubmed/1712231002084nas a2200229   4500008004100000022001400041245009200055210006900147260001200216300001400228490000700242520141400249653001701663100002101680700002201701700001301723700001301736700001301749700002301762700002101785856004801806       2007                        eng d  a0022-307700aSpinal and supraspinal effects of long-term stimulation of sensorimotor cortex in rats.0 aSpinal and supraspinal effects of longterm stimulation of sensor  c08/2007  a878–8870 v983 aSensorimotor cortex (SMC) modifies spinal cord reflex function throughout life and is essential for operant conditioning of the H-reflex. To further explore this long-term SMC influence over spinal cord function and its possible clinical uses, we assessed the effect of long-term SMC stimulation on the soleus H-reflex. In freely moving rats, the soleus H-reflex was measured 24 h/day for 12 wk. The soleus background EMG and M response associated with H-reflex elicitation were kept stable throughout. SMC stimulation was delivered in a 20-day-on/20-day-off/20-day-on protocol in which a train of biphasic 1-ms pulses at 25 Hz for 1 s was delivered every 10 s for the on-days. The SMC stimulus was automatically adjusted to maintain a constant descending volley. H-reflex size gradually increased during the 20 on-days, stayed high during the 20 off-days, and rose further during the next 20 on-days. In addition, the SMC stimulus needed to maintain a stable descending volley rose steadily over days. It fell during the 20 off-days and rose again when stimulation resumed. These results suggest that SMC stimulation, like H-reflex operant conditioning, induces activity-dependent plasticity in both the brain and the spinal cord and that the plasticity responsible for the H-reflex increase persists longer after the end of SMC stimulation than that underlying the change in the SMC response to stimulation.10aTime Factors1 aChen, Xiang Yang1 aPillai, Shreejith1 aChen, Yi1 aWang, Yu1 aChen, Lu1 aCarp, Jonathan, S.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1752217902003nas a2200241   4500008004100000022001400041245007500055210006900130260001200199300001400211490000800225520132900233653001701562653001301579653001301592653001101605653001901616653001501635653001901650653002301669100002101692856004801713       2007                        eng d  a1748-170800aSpinal cord plasticity in acquisition and maintenance of motor skills.0 aSpinal cord plasticity in acquisition and maintenance of motor s  c02/2007  a155–1690 v1893 aThroughout normal life, activity-dependent plasticity occurs in the spinal cord as well as in brain. Like other central nervous system (CNS) plasticity, spinal cord plasticity can occur at numerous neuronal and synaptic sites and through a variety of mechanisms. Spinal cord plasticity is prominent early in life and contributes to mastery of standard behaviours like locomotion and rapid withdrawal from pain. Later in life, spinal cord plasticity has a role in acquisition and maintenance of new motor skills, and in compensation for peripheral and central changes accompanying ageing, disease and trauma. Mastery of the simplest behaviours is accompanied by complex spinal and supraspinal plasticity. This complexity is necessary, in order to preserve the complete behavioural repertoire, and is also inevitable, due to the ubiquity of activity-dependent CNS plasticity. Explorations of spinal cord plasticity are necessary for understanding motor skills. Furthermore, the spinal cord's comparative simplicity and accessibility makes it a logical starting point for studying skill acquisition. Induction and guidance of activity-dependent spinal cord plasticity will probably play an important role in realization of effective new rehabilitation methods for spinal cord injuries, cerebral palsy and other motor disorders.10aconditioning10aH-Reflex10aLearning10aMemory10amotor function10aplasticity10aRehabilitation10aspinal cord injury1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1725056602623nas a2200289   4500008004100000022001400041245008600055210007000141260001200211300001100223490000700234520175100241653001501992653002002007653002902027653002702056653002202083653001102105653001602116653003502132653002802167100002402195700001902219700002602238700002102264856004802285       2007                        eng d  a0018-929400aA µ-rhythm Matched Filter for  Continuous Control of a Brain-Computer Interface.0 aµrhythm Matched Filter for Continuous Control of a BrainComputer  c02/2007  a273-800 v543 a<p><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">A brain-computer interface (BCI) is a system that provides an alternate nonmuscular communication/control channel for individuals with severe neuromuscular disabilities. With proper training, individuals can learn to modulate the amplitude of specific electroencephalographic (</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">EEG</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">) components (e.g., the 8-12 Hz mu rhythm and 18-26 Hz beta rhythm) over the sensorimotor cortex and use them to control a cursor on a computer screen. Conventional spectral techniques for monitoring the&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">continuous</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">amplitude fluctuations fail to capture essential amplitude/phase relationships of the mu and beta rhythms in a compact fashion and, therefore, are suboptimal. By extracting the characteristic mu rhythm for a user, the exact morphology can be characterized and exploited as a matched filter. A simple, parameterized model for the characteristic mu rhythm is proposed and its effectiveness as a matched filter is examined online for a one-dimensional cursor control task. The results suggest that amplitude/phase coupling exists between the mu and beta bands during event-related desynchronization, and that an appropriate matched filter can provide improved performance.</span></p>10aAlgorithms10aCerebral Cortex10aCortical Synchronization10aElectroencephalography10aEvoked Potentials10aHumans10aImagination10aPattern Recognition, Automated10aUser-Computer Interface1 aKrusienski, Dean, J1 aSchalk, Gerwin1 aMcFarland, Dennis, J.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1727858403802nas a2200385   4500008004100000022001400041245008700055210006900142260001200211300001000223490000700233520264300240653001502883653001002898653003602908653002302944653002702967653002202994653001103016653002703027653002403054653003803078653002803116100002403144700002603168700002403194700001903218700002103237700002003258700002403278700002203302700002303324700002103347856004803368       2006                        eng d  a1534-432000aThe BCI competition III: Validating alternative approaches to actual BCI problems.0 aBCI competition III Validating alternative approaches to actual   c06/2006  a153-90 v143 a<p><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">A&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">brain-computer interface</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;(BCI) is a system that allows its users to control external devices with&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">brain</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">activity. Although the proof-of-concept was given decades ago, the reliable translation of user intent into device control commands is still a major challenge. Success requires the effective interaction of two adaptive controllers: the user's&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">brain</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">, which produces&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">brain</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;activity that encodes intent, and the BCI system, which translates that activity into device control commands. In order to facilitate this interaction, many laboratories are exploring a variety of signal analysis techniques to improve the adaptation of the BCI system to the user. In the literature, many machine learning and pattern classification algorithms have been reported to give impressive results when applied to BCI data in offline analyses. However, it is more difficult to evaluate their relative value for actual&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">online</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;use. BCI data competitions have been organized to provide objective formal evaluations of alternative methods. Prompted by the great interest in the first two BCI Competitions, we organized the third BCI Competition to address several of the most difficult and important analysis problems in BCI research. The paper describes the data sets that were provided to the competitors and gives an overview of the results.</span></p>10aAlgorithms10aBrain10aCommunication Aids for Disabled10aDatabases, Factual10aElectroencephalography10aEvoked Potentials10aHumans10aNeuromuscular Diseases10aSoftware Validation10aTechnology Assessment, Biomedical10aUser-Computer Interface1 aBlankertz, Benjamin1 aMüller, Klaus-Robert1 aKrusienski, Dean, J1 aSchalk, Gerwin1 aWolpaw, Jonathan1 aSchlögl, Alois1 aPfurtscheller, Gert1 aMillán, José, R1 aSchröder, Michael1 aBirbaumer, Niels  uhttp://www.ncbi.nlm.nih.gov/pubmed/1679228201530nas a2200277   4500008004100000022001400041245006600055210006500121260001200186300001400198490000700212520068900219653003500908653003300943653001900976100002100995700002101016700002501037700002101062700003001083700002701113700001901140700002301159700002201182856004801204       2006                        eng d  a1534-432000aBCI Meeting 2005–workshop on signals and recording methods.0 aBCI Meeting 2005–workshop on signals and recording methods  c06/2006  a138–1410 v143 aThis paper describes the highlights of presentations and discussions during the Third International BCI Meeting in a workshop that evaluated potential brain-computer interface (BCI) signals and currently available recording methods. It defined the main potential user populations and their needs, addressed the relative advantages and disadvantages of noninvasive and implanted (i.e., invasive) methodologies, considered ethical issues, and focused on the challenges involved in translating BCI systems from the laboratory to widespread clinical use. The workshop stressed the critical importance of developing useful applications that establish the practical value of BCI technology.10aBrain-computer interface (BCI)10aelectrophysiological signals10aRehabilitation1 aWolpaw, Jonathan1 aLoeb, Gerald, E.1 aAllison, Brendan, Z.1 aDonchin, Emanuel1 aNascimento, Omar, Feix do1 aHeetderks, William, J.1 aNijboer, Femke1 aShain, William, G.1 aTurner, James, N.  uhttp://www.ncbi.nlm.nih.gov/pubmed/1679227901505nas a2200205   4500008004100000022001400041245010600055210006900161260001200230300001400242490000800256520087000264653001501134653000801149653002201157100002601179700002501205700002101230856004801251       2006                        eng d  a0079-612300aBrain-computer interface signal processing at the Wadsworth Center: mu and sensorimotor beta rhythms.0 aBraincomputer interface signal processing at the Wadsworth Cente  c02/2006  a411–4190 v1593 aThe Wadsworth brain-computer interface (BCI), based on mu and beta sensorimotor rhythms, uses one- and two-dimensional cursor movement tasks and relies on user training. This is a real-time closed-loop system. Signal processing consists of channel selection, spatial filtering, and spectral analysis. Feature translation uses a regression approach and normalization. Adaptation occurs at several points in this process on the basis of different criteria and methods. It can use either feedforward (e.g., estimating the signal mean for normalization) or feedback control (e.g., estimating feature weights for the prediction equation). We view this process as the interaction between a dynamic user and a dynamic system that coadapt over time. Understanding the dynamics of this interaction and optimizing its performance represent a major challenge for BCI research.10aadaptation10aBCI10aSignal Processing1 aMcFarland, Dennis, J.1 aKrusienski, Dean, J.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1707124502251nas a2200169   4500008004100000022001400041245013300055210006900188260001200257300001400269490000700283520168500290653001601975100002101991700002102012856004802033       2006                        eng d  a1072-050200aThe cerebellum in maintenance of a motor skill: a hierarchy of brain and spinal cord plasticity underlies H-reflex conditioning.0 acerebellum in maintenance of a motor skill a hierarchy of brain   c03/2006  a208–2150 v133 aOperant conditioning of the H-reflex, the electrical analog of the spinal stretch reflex, is a simple model of skill acquisition and involves plasticity in the spinal cord. Previous work showed that the cerebellum is essential for down-conditioning the H-reflex. This study asks whether the cerebellum is also essential for maintaining down-conditioning. After rats decreased the soleus H-reflex over 50 d in response to the down-conditioning protocol, the cerebellar output nuclei dentate and interpositus (DIN) were ablated, and down-conditioning continued for 50-100 more days. In naive (i.e., unconditioned) rats, DIN ablation itself has no significant long-term effect on H-reflex size. During down-conditioning prior to DIN ablation, eight Sprague-Dawley rats decreased the H-reflex to 57% (+/-4 SEM) of control. It rose after ablation, stabilizing within 2 d at about 75% and remaining there until approximately 40 d after ablation. It then rose to approximately 130%, where it remained through the end of study 100 d after ablation. Thus, DIN ablation in down-conditioned rats caused an immediate increase and a delayed increase in the H-reflex. The final result was an H-reflex significantly larger than that prior to down-conditioning. Combined with previous work, these remarkable results suggest that the spinal cord plasticity directly responsible for down-conditioning, which survives only 5-10 d on its own, is maintained by supraspinal plasticity that survives approximately 40 d after loss of cerebellar output. Thus, H-reflex conditioning seems to depend on a hierarchy of brain and spinal cord plasticity to which the cerebellum makes an essential contribution.10aSpinal Cord1 aWolpaw, Jonathan1 aChen, Xiang Yang  uhttp://www.ncbi.nlm.nih.gov/pubmed/1658579601626nas a2200229   4500008004100000022001400041245006800055210006500123260001200188300001400200490000600214520094100220653002401161100002501185700002201210700002601232700001901258700002601277700002401303700002101327856004801348       2006                        eng d  a1741-256000aA comparison of classification techniques for the P300 Speller.0 acomparison of classification techniques for the P300 Speller  c12/2006  a299–3050 v33 aThis study assesses the relative performance characteristics of five established classification techniques on data collected using the P300 Speller paradigm, originally described by Farwell and Donchin (1988 Electroenceph. Clin. Neurophysiol. 70 510). Four linear methods: Pearson's correlation method (PCM), Fisher's linear discriminant (FLD), stepwise linear discriminant analysis (SWLDA) and a linear support vector machine (LSVM); and one nonlinear method: Gaussian kernel support vector machine (GSVM), are compared for classifying offline data from eight users. The relative performance of the classifiers is evaluated, along with the practical concerns regarding the implementation of the respective methods. The results indicate that while all methods attained acceptable performance levels, SWLDA and FLD provide the best overall performance and implementation characteristics for practical classification of P300 Speller data.10aNormal Distribution1 aKrusienski, Dean, J.1 aSellers, Eric, W.1 aCabestaing, François1 aBayoudh, Sabri1 aMcFarland, Dennis, J.1 aVaughan, Theresa, M1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1712433402272nas a2200253   4500008004100000022001400041245009400055210006900149260001200218300001600230490000700246520153000253653002401783653002601807653001501833653000801848653002301856100002101879700001301900700001301913700002301926700002101949856004801970       2006                        eng d  a0897-715100aCorticospinal tract transection permanently abolishes H-reflex down-conditioning in rats.0 aCorticospinal tract transection permanently abolishes Hreflex do  c11/2006  a1705–17120 v233 aPrevious studies have shown that corticospinal tract (CST) transection, but not transection of other major spinal cord tracts, prevents down-conditioning of the H-reflex, the electrical analog of the spinal stretch reflex. This study set out to determine whether the loss of the capacity for H-reflex down-conditioning caused by CST transection is permanent. Female Sprague-Dawley rats received CST, lateral column (LC), or dorsal column ascending tract (DA) transection at T8-9; 9-10 months later, they were exposed to the H-reflex down-conditioning protocol for 50 days. In the LC and DA rats, H-reflex size fell to 60 (+/- 9 SEM)% and 60 (+/- 19)%, respectively, of its initial size. This down-conditioning was comparable to that of normal rats. In contrast, H-reflex size in the CST rats rose to 170 (+/- 42)% of its initial size. A similar rise does not occur in rats exposed to down-conditioning shortly after CST transection. These results indicate that CST transection permanently eliminates the capacity for H-reflex down-conditioning and has gradual long-term effects on sensorimotor cortex function. They imply that H-reflex down-conditioning can be a reliable measure of CST function for long-term studies of the effects of spinal cord injury and/or for evaluations of the efficacy of experimental therapeutic procedures, such as those intended to promote CST regeneration. The results also suggest that the role of sensorimotor cortex in down-conditioning extends beyond generation of the essential CST activity.10acorticospinal tract10aH-reflex conditioning10aplasticity10arat10aspinal cord injury1 aChen, Xiang Yang1 aChen, Yi1 aChen, Lu1 aTennissen, Ann, M.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1711591502091nas a2200253   4500008004100000022001400041245004000055210003800095260001200133300001400145490000800159520142300167653002101590653002101611653002501632653001701657653001101674653001601685100002301701700002301724700002101747700002101768856004801789       2006                        eng d  a0014-481900aDiurnal H-reflex variation in mice.0 aDiurnal Hreflex variation in mice  c01/2006  a517–5280 v1683 aMice exhibit diurnal variation in complex motor behaviors, but little is known about diurnal variation in simple spinally mediated functions. This study describes diurnal variation in the H-reflex (HR), a wholly spinal and largely monosynaptic reflex. Six mice were implanted with tibial nerve cuff electrodes and electrodes in the soleus and gastrocnemius muscles, for recording of ongoing and nerve-evoked electromyographic activity (EMG). Stimulation and recording were under computer control 24 h/day. During a 10-day recording period, HR amplitude varied throughout the day, usually being larger in the dark than in the light. This diurnal HR variation could not be attributed solely to differences in the net ongoing level of descending and segmental excitation to the spinal cord or stimulus intensity. HRs were larger in the dark than in the light even after restricting the evoked responses to subsets of trials having similar ongoing EMG and M-responses. The diurnal variation in the HR was out of phase with that reported previously for rats, but was in phase with that observed in monkeys. These data, supported by those in other species, suggest that the supraspinal control of the excitability of the HR pathway varies throughout the day in a species-specific pattern. This variation should be taken into account in experimental and clinical studies of spinal reflexes recorded at different times of day.10acircadian rhythm10aElectromyography10aimplanted electrodes10aMonosynaptic10aReflex10aSpinal Cord1 aCarp, Jonathan, S.1 aTennissen, Ann, M.1 aChen, Xiang Yang1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1615178101977nas a2200229   4500008004100000022001400041245005500055210004900110260001200159300001400171490000800185520137700193653001301570653001701583653001301600653001101613653001501624653001601639653002301655100002101678856004801699       2006                        eng d  a0079-612300aThe education and re-education of the spinal cord.0 aeducation and reeducation of the spinal cord  c02/2006  a261–2800 v1573 aIn normal life, activity-dependent plasticity occurs in the spinal cord as well as in the brain. Like CNS plasticity elsewhere, this spinal cord plasticity can occur at many neuronal and synaptic sites and by a variety of mechanisms. Spinal cord plasticity is prominent in postnatal development and contributes to acquisition of standard behaviors such as locomotion and rapid withdrawal from pain. Later on in life, spinal cord plasticity contributes to acquisition and maintenance of specialized motor skills, and to compensation for the peripheral and central changes associated with aging, disease, and trauma. Mastery of even the simplest behaviors is accompanied by complex spinal and supraspinal plasticity. This complexity is necessary, to preserve the full roster of behaviors, and is also inevitable, due to the ubiquity of activity-dependent plasticity in the CNS. Careful investigation of spinal cord plasticity is essential for understanding motor skills; and, because of the relative simplicity and accessibility of the spinal cord, is a logical and convenient starting point for exploring skill acquisition. Appropriate induction and guidance of activity-dependent plasticity in the spinal cord is likely to be a key part of the realization of effective new rehabilitation methods for spinal cord injuries, cerebral palsy, and other chronic motor disorders.10abehavior10aconditioning10aLearning10aMemory10aplasticity10aSpinal Cord10aspinal cord injury1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1716791601404nas a2200181   4500008004100000022001400041245011100055210006900166260001200235300001600247490000600263520080700269653002801076100002301104700002601127700002101153856004801174       2006                        eng d  a1557-170X00aAn evaluation of autoregressive spectral estimation model order for brain-computer interface applications.0 aevaluation of autoregressive spectral estimation model order for  c09/2006  a1323–13260 v13 aAutoregressive (AR) spectral estimation is a popular method for modeling the electroencephalogram (EEG), and therefore the frequency domain EEG phenomena that are used for control of a brain-computer interface (BCI). Several studies have been conducted to evaluate the optimal AR model order for EEG, but the criteria used in these studies does not necessarily equate to the optimal AR model order for sensorimotor rhythm (SMR)-based BCI control applications. The present study confirms this by evaluating the EEG spectra of data obtained during control of SMR-BCI using different AR model orders and model evaluation criteria. The results indicate that the AR model order that optimizes SMR-BCI control performance is generally higher than the model orders that are frequently used in SMR-BCI studies.10aUser-Computer Interface1 aKrusienski, D., J.1 aMcFarland, Dennis, J.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1794603802319nas a2200193   4500008004100000022001400041245004300055210004100098260001200139300001600151490000700167520179900174653001601973100002301989700002302012700002102035700002102056856004802077       2006                        eng d  a0022-307700aH-reflex operant conditioning in mice.0 aHreflex operant conditioning in mice  c10/2006  a1718–17270 v963 aRats, monkeys, and humans can alter the size of their spinal stretch reflex and its electrically induced analog, the H-reflex (HR), when exposed to an operant conditioning paradigm. Because this conditioning induces plasticity in the spinal cord, it offers a unique opportunity to identify the neuronal sites and mechanisms that underlie a well-defined change in a simple behavior. To facilitate these studies, we developed an HR operant conditioning protocol in mice, which are better suited to genetic manipulation and electrophysiological spinal cord study in vitro than rats or primates. Eleven mice under deep surgical anesthesia were implanted with tibial nerve stimulating electrodes and soleus and gastrocnemius intramuscular electrodes for recording ongoing and stimulus-evoked EMG activity. During the 24-h/day computer-controlled experiment, mice received a liquid reward for either increasing (up-conditioning) or decreasing (down-conditioning) HR amplitude while maintaining target levels of ongoing EMG and directly evoked EMG (M-responses). After 3-7 wk of conditioning, the HR amplitude was 133 +/- 7% (SE) of control for up-conditioning and 71 +/- 8% of control for down-conditioning. HR conditioning was successful (i.e., > or =20% change in HR amplitude in the appropriate direction) in five of six up-conditioned animals (mean final HR amplitude = 139 +/- 5% of control HR for successful mice) and in four of five down-conditioned animals (mean final HR amplitude = 63 +/- 8% of control HR for successful mice). These effects were not attributable to differences in the net level of motoneuron pool excitation, stimulation strength, or distribution of HR trials throughout the day. Thus mice exhibit HR operant conditioning comparable with that observed in rats and monkeys.10aSpinal Cord1 aCarp, Jonathan, S.1 aTennissen, Ann, M.1 aChen, Xiang Yang1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1683765902744nas a2200193   4500008004100000022001400041245011800055210006900173260001200242300001600254490000600270520212200276653001602398100002302414700002302437700002102460700002102481856004802502       2006                        eng d  a1557-170X00aModulation in spinal circuits and corticospinal connections following nerve stimulation and operant conditioning.0 aModulation in spinal circuits and corticospinal connections foll  c09/2006  a2138–21410 v13 aNeural plasticity occurs throughout adult life. In healthy individuals, different spinal pathways are differently modulated during different daily activities. Drastic changes to nervous system activity and connections caused by injuries or diseases alter spinal reflexes, and this is often related to disturbed motor functions. In both health and disease, spinal reflexes are subject to substantial modifications. Plasticity in supraspinal descending connections is even more remarkable; corticospinal connectivity has been shown to be extremely plastic. In this session, we describe two approaches for possibly improving recovery after central nervous system (CNS) lesions. They are very different, but both involve repetitive nerve stimulation and CNS plasticity. The first approach is functional electrical stimulation (FES) of the common peroneal nerve, which has been used to treat foot drop in patients with CNS lesions. The second approach is operant conditioning of a spinal reflex. Spinal reflex operant conditioning studies in animal models have shown plastic changes in spinal cord neurons associated with this form of learning and improved locomotor function in incomplete spinal cord injured rats. Thus, reflex conditioning might be a robust approach to inducing plasticity at spinal and supraspinal levels. As a first step in establishing this approach and characterizing its effects in the human adult CNS, we are currently investigating the extent and time course of operant conditioning of the soleus H-reflex in healthy subjects. In results to date, all subjects (n=5) have changed reflex size in the correct direction to various degree (16-36%) over 2-3 months of conditioning, indicating possibility that H-reflex conditioning can occur in humans. At the same time, the substantial inter-subject variation in the time course and extent of conditioning suggest that additional data are needed to establish its principal features. We hope that studying modulation and modification o- f the CNS by different approaches will help us further understand the plasticity of the human adult nervous system.10aSpinal Cord1 aThompson, Aiko, K.1 aStein, Richard, B.1 aChen, Xiang Yang1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1794693902175nas a2200253   4500008004100000022001400041245008500055210006900140260001200209300001400221490000700235520145300242653003401695653000901729653001301738653001101751653001801762653001601780100001301796700002201809700002101831700002101852856004801873       2006                        eng d  a0953-816X00aMotor learning changes GABAergic terminals on spinal motoneurons in normal rats.0 aMotor learning changes GABAergic terminals on spinal motoneurons  c01/2006  a141–1500 v233 aThe role of spinal cord plasticity in motor learning is largely unknown. This study explored the effects of H-reflex operant conditioning, a simple model of motor learning, on GABAergic input to spinal motoneurons in rats. Soleus motoneurons were labeled by retrograde transport of a fluorescent tracer and GABAergic terminals on them were identified by glutamic acid decarboxylase (GAD)67 immunoreactivity. Three groups were studied: (i) rats in which down-conditioning had reduced the H-reflex (successful HRdown rats); (ii) rats in which down-conditioning had not reduced the H-reflex (unsuccessful HRdown rats) and (iii) unconditioned (naive) rats. The number, size and GAD density of GABAergic terminals, and their coverage of the motoneuron, were significantly greater in successful HRdown rats than in unsuccessful HRdown or naive rats. It is likely that these differences are due to modifications in terminals from spinal interneurons in lamina VI-VII and that the increased terminal number, size, GAD density and coverage in successful HRdown rats reflect and convey a corticospinal tract influence that changes motoneuron firing threshold and thereby decreases the H-reflex. GABAergic terminals in spinal cord change after spinal cord transection. The present results demonstrate that such spinal cord plasticity also occurs in intact rats in the course of motor learning and suggest that this plasticity contributes to skill acquisition.10aactivity-dependent plasticity10aGABA10aH-Reflex10aMemory10aMotor control10aSpinal Cord1 aWang, Yu1 aPillai, Shreejith1 aWolpaw, Jonathan1 aChen, Xiang Yang  uhttp://www.ncbi.nlm.nih.gov/pubmed/1642042401903nas a2200301   4500008004100000022001400041245010700055210006900162260001200231300001800243490000700261520101900268653002601287653001301313653001501326653001101341653001801352653001901370653002301389653002701412100001301439700002101452700002101473700001301494700002501507700002101532856004801553       2006                        eng d  a1529-240100aOperant conditioning of H-reflex can correct a locomotor abnormality after spinal cord injury in rats.0 aOperant conditioning of Hreflex can correct a locomotor abnormal  c11/2006  a12537–125430 v263 a<p>This study asked whether operant conditioning of the H-reflex can modify locomotion in spinal cord-injured rats. Midthoracic transection of the right lateral column of the spinal cord produced a persistent asymmetry in the muscle activity underlying treadmill locomotion. The rats were then either exposed or not exposed to an H-reflex up-conditioning protocol that greatly increased right soleus motoneuron response to primary afferent input, and locomotion was reevaluated. H-reflex up-conditioning increased the right soleus burst and corrected the locomotor asymmetry. In contrast, the locomotor asymmetry persisted in the control rats. These results suggest that appropriately selected reflex conditioning protocols might improve function in people with partial spinal cord injuries. Such protocols might be especially useful when significant regeneration becomes possible and precise methods for reeducating the regenerated spinal cord neurons and synapses are needed for restoring effective function.</p>10aH-reflex conditioning10aLearning10aLocomotion10aMemory10aMotor control10aRehabilitation10aspinal cord injury10aspinal cord plasticity1 aChen, Yi1 aChen, Xiang Yang1 aJakeman, Lyn, B.1 aChen, Lu1 aStokes, Bradford, T.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1713541502210nas a2200205   4500008004100000022001400041245007200055210006900127260001200196300001600208490000700224520163400231653001101865653001201876100002101888700001301909700001301922700002101935856004801956       2006                        eng d  a0022-307700aOperant conditioning of reciprocal inhibition in rat soleus muscle.0 aOperant conditioning of reciprocal inhibition in rat soleus musc  c10/2006  a2144–21500 v963 aOperant conditioning of the H-reflex, the electrical analog of the spinal stretch reflex (SSR), induces activity-dependent plasticity in the spinal cord and might be used to improve locomotion after spinal cord injury. To further assess the potential clinical significance of spinal reflex conditioning, this study asks whether another well-defined spinal reflex pathway, the disynaptic pathway underlying reciprocal inhibition (RI), can also be operantly conditioned. Sprague-Dawley rats were implanted with electromyographic (EMG) electrodes in right soleus (SOL) and tibialis anterior (TA) muscles and a stimulating cuff on the common peroneal (CP) nerve. When background EMG in both muscles remained in defined ranges, CP stimulation elicited the TA H-reflex and SOL RI. After collection of control data for 20 days, each rat was exposed for 50 days to up-conditioning (RIup mode) or down-conditioning (RIdown mode) in which food reward occurred if SOL RI evoked by CP stimulation was more (RIup mode) or less (RIdown mode) than a criterion. TA and SOL background EMG and TA M response remained stable. In every rat, RI conditioning was successful (i.e., change > or =20% in the correct direction). In the RIup rats, final SOL RI averaged 171+/- 28% (mean +/- SE) of control, and final TA H-reflex averaged 114 +/- 14%. In the RIdown rats, final SOL RI averaged 37 +/- 13% of control, and final TA H-reflex averaged 60 +/- 18%. Final SOL RI and TA H-reflex sizes were significantly correlated. Thus like the SSR and the H-reflex, RI can be operantly conditioned; and conditioning one reflex can affect another reflex as well.10aReflex10aStretch1 aChen, Xiang Yang1 aChen, Lu1 aChen, Yi1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1680735102016nas a2200265   4500008004100000022001400041245013800055210006900193260001200262300001400274490000700288520114400295653003401439653002901473653002501502653002901527653000901556653001901565100002201584700002501606700002601631700002401657700002101681856004801702       2006                        eng d  a0301-051100aA P300 event-related potential brain-computer interface (BCI): the effects of matrix size and inter stimulus interval on performance.0 aP300 eventrelated potential braincomputer interface BCI the effe  c10/2006  a242–2520 v733 aWe describe a study designed to assess properties of a P300 brain-computer interface (BCI). The BCI presents the user with a matrix containing letters and numbers. The user attends to a character to be communicated and the rows and columns of the matrix briefly intensify. Each time the attended character is intensified it serves as a rare event in an oddball sequence and it elicits a P300 response. The BCI works by detecting which character elicited a P300 response. We manipulated the size of the character matrix (either 3 x 3 or 6 x 6) and the duration of the inter stimulus interval (ISI) between intensifications (either 175 or 350 ms). Online accuracy was highest for the 3 x 3 matrix 175-ms ISI condition, while bit rate was highest for the 6 x 6 matrix 175-ms ISI condition. Average accuracy in the best condition for each subject was 88%. P300 amplitude was significantly greater for the attended stimulus and for the 6 x 6 matrix. This work demonstrates that matrix size and ISI are important variables to consider when optimizing a BCI system for individual users and that a P300-BCI can be used for effective communication.10aAmyotrophic Lateral Sclerosis10abrain-computer interface10aelectroencephalogram10aevent-related potentials10aP30010aRehabilitation1 aSellers, Eric, W.1 aKrusienski, Dean, J.1 aMcFarland, Dennis, J.1 aVaughan, Theresa, M1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1686092002190nas a2200253   4500008004100000022001400041245009500055210006900150260001200219300001600231490000800247520145200255653001301707653001501720653001101735653001501746653001601761100002501777700001901802700002201821700002101843700002401864856004801888       2006                        eng d  a1388-245700aPlastic changes in the human H-reflex pathway at rest following skillful cycling training.0 aPlastic changes in the human Hreflex pathway at rest following s  c08/2006  a1682–16910 v1173 aOBJECTIVE:
The spinal cord is capable of activity-dependent plasticity, but the extent of its participation in human motor learning is not known. Here, we tested the hypothesis that acquisition of a locomotor-related skill modulates the pathway of the H-reflex, a measure of spinal cord excitability that is susceptible to plastic changes.
METHODS:
Subjects were tested on their ability to establish a constant cycling speed on a recumbent bike despite frequent changes in pedal resistance. The coefficient of variation of speed (CV(speed)) measured their ability to acquire this skill (decreasing CV(speed) with training reflects performance improvements). Soleus H-reflexes were taken at rest before and after cycling.
RESULTS:
Ability to establish a target speed increased and H-reflex size decreased more after cycling training involving frequent changes in pedal resistance that required calibrated locomotor compensatory action than with training involving constant pedal resistances and lesser compensation. The degree of performance improvement correlated with the reduction in the amplitude of the H-reflex.
CONCLUSIONS:
Skillful establishment of a constant cycling speed despite changing pedal resistances is associated with persistent modulation of activity in spinal pathways.
SIGNIFICANCE:
Recalibration of activity in the H-reflex pathway may be part of the control strategy required for locomotor-related skill acquisition.10aH-Reflex10aLocomotion10aMemory10aplasticity10aSpinal Cord1 aMazzocchio, Riccardo1 aKitago, Tomoko1 aLiuzzi, Gianpiero1 aWolpaw, Jonathan1 aCohen, Leonardo, G.  uhttp://www.ncbi.nlm.nih.gov/pubmed/1679333302728nas a2200253   4500008004100000022001400041245003700055210003600092260001200128300001400140490000700154520210100161653002302262653001602285653001302301653001102314653001502325653001102340653001502351653001602366100002102382700002302403856004802426       2006                        eng d  a0301-008200aPlasticity from muscle to brain.0 aPlasticity from muscle to brain  c02/2006  a233–2630 v783 aRecognition that the entire central nervous system (CNS) is highly plastic, and that it changes continually throughout life, is a relatively new development. Until very recently, neuroscience has been dominated by the belief that the nervous system is hardwired and changes at only a few selected sites and by only a few mechanisms. Thus, it is particularly remarkable that Sir John Eccles, almost from the start of his long career nearly 80 years ago, focused repeatedly and productively on plasticity of many different kinds and in many different locations. He began with muscles, exploring their developmental plasticity and the functional effects of the level of motor unit activity and of cross-reinnervation. He moved into the spinal cord to study the effects of axotomy on motoneuron properties and the immediate and persistent functional effects of repetitive afferent stimulation. In work that combined these two areas, Eccles explored the influences of motoneurons and their muscle fibers on one another. He studied extensively simple spinal reflexes, especially stretch reflexes, exploring plasticity in these reflex pathways during development and in response to experimental manipulations of activity and innervation. In subsequent decades, Eccles focused on plasticity at central synapses in hippocampus, cerebellum, and neocortex. His endeavors extended from the plasticity associated with CNS lesions to the mechanisms responsible for the most complex and as yet mysterious products of neuronal plasticity, the substrates underlying learning and memory. At multiple levels, Eccles' work anticipated and helped shape present-day hypotheses and experiments. He provided novel observations that introduced new problems, and he produced insights that continue to be the foundation of ongoing basic and clinical research. This article reviews Eccles' experimental and theoretical contributions and their relationships to current endeavors and concepts. It emphasizes aspects of his contributions that are less well known at present and yet are directly relevant to contemporary issues.10aactivity-dependent10aJohn Eccles10aLearning10aMemory10amotor unit10amuscle10aplasticity10aSpinal Cord1 aWolpaw, Jonathan1 aCarp, Jonathan, S.  uhttp://www.ncbi.nlm.nih.gov/pubmed/1664718102294nas a2200193   4500008004100000022001400041245013100055210006900186260001200255300001400267490000700281520166100288653002501949100002101974700002301995700001302018700002102031856004802052       2006                        eng d  a0022-307700aSensorimotor cortex ablation prevents H-reflex up-conditioning and causes a paradoxical response to down-conditioning in rats.0 aSensorimotor cortex ablation prevents Hreflex upconditioning and  c07/2006  a119–1270 v963 aOperant conditioning of the H-reflex, a simple model for skill acquisition, requires the corticospinal tract (CST) and does not require other major descending pathways. To further explore its mechanisms, we assessed the effects of ablating contralateral sensorimotor cortex (cSMC). In 22 Sprague-Dawley rats, the hindlimb area of left cSMC was ablated. EMG electrodes were implanted in the right soleus muscle and a stimulating cuff was placed around the right posterior tibial nerve. When EMG remained in a specified range, nerve stimulation just above the M response threshold elicited the H-reflex. In control mode, no reward occurred. In conditioning mode, reward occurred if H-reflex size was above (HRup mode) or below (HRdown mode) a criterion value. After exposure to the control mode for > or = 10 days, each rat was exposed for another 50 days to the control mode, the HRup mode, or the HRdown mode. In control and HRup rats, final H-reflex size was not significantly different from initial H-reflex size. In contrast, in HRdown rats, final H-reflex size was significantly increased to an average of 136% of initial size. Thus like recent CST transection, cSMC ablation greatly impaired up-conditioning. However, unlike recent CST transection, cSMC produced a paradoxical response to down-conditioning: the H-reflex actually increased. These results confirm the critical role of cSMC in H-reflex conditioning and suggest that this role extends beyond producing essential CST activity. Its interactions with ipsilateral SMC or other areas contribute to the complex pattern of spinal and supraspinal plasticity that underlies H-reflex conditioning.10aSomatosensory Cortex1 aChen, Xiang Yang1 aCarp, Jonathan, S.1 aChen, Lu1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1659806201922nas a2200169   4500008004100000022001400041245009700055210006900152260001200221300001400233490000700247520137700254653002801631100002401659700002101683856004801704       2006                        eng d  a1534-432000aThe Third International Meeting on Brain-Computer Interface Technology: making a difference.0 aThird International Meeting on BrainComputer Interface Technolog  c06/2006  a126–1270 v143 aThis special issue of the IEEE TRANSACTIONS ON NEURAL SYSTEMS AND REHABILITATION ENGINEERING provides a representative and comprehensive bird's-eye view of the most recent developments in brain-computer interface (BCI) technology from laboratories around the world. The 30 research communications and papers are the direct outcome of the Third International Meeting on Brain-Computer Interface Technology held at the Rensselaerville Institute, Rensselaerville, NY, in June 2005. Fifty-three research groups from North and South America, Europe, and Asia, representing the majority of all the existing BCI laboratories around the world, participated in this highly focused meeting sponsored by the National Institutes of Health and organized by the BCI Laboratory of the Wadsworth Center of the New York State Department of Health. As demonstrated by the papers in this special issue, the rapid advances in BCI research and development make this technology capable of providing communication and control to people severely disabled by amyotrophic lateral sclerosis (ALS), brainstem stroke, cerebral palsy, and other neuromuscular disorders. Future work is expected to improve the performance and utility of BCIs, and to focus increasingly on making them a viable, practical, and affordable communication alternative for many thousands of severely disabled people worldwide.10aUser-Computer Interface1 aVaughan, Theresa, M1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1679227500453nas a2200145   4500008004100000022001400041245007000055210006800125260001200193300001400205490000700219653001200226100002100238856004800259       2006                        eng d  a1526-632X00aTreadmill training after spinal cord injury: good but not better.0 aTreadmill training after spinal cord injury good but not better  c02/2006  a466–4670 v6610aWalking1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1650529402977nas a2200361   4500008004100000022001400041245007400055210006800129260001200197300001100209490000700220520195300227653001202180653001002192653002702202653002202229653001102251653002702262653001302289653001302302653001602315653003102331653001702362653002802379100002402407700002602431700001902457700002502476700002402501700002102525700002102546856004802567       2006                        eng d  a1534-432000aThe Wadsworth BCI Research and Development Program: At Home with BCI.0 aWadsworth BCI Research and Development Program At Home with BCI  c06/2006  a229-330 v143 a<p><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">The ultimate goal of brain-computer interface (BCI) technology is to provide communication and control capacities to people with severe motor disabilities. BCI research at the Wadsworth Center focuses primarily on noninvasive,&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">electroencephalography</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;(</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">EEG</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">)-based BCI methods. We have shown that people, including those with severe motor disabilities, can learn to use sensorimotor rhythms (SMRs) to move a cursor rapidly and accurately in one or two dimensions. We have also improved P300-based BCI operation. We are now translating this laboratory-proven BCI technology into a system that can be used by severely disabled people in their homes with minimal ongoing technical oversight. To accomplish this, we have: improved our general-purpose BCI software (BCI2000); improved online adaptation and feature translation for SMR-based BCI operation; improved the accuracy and bandwidth of P300-based BCI operation; reduced the&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">complexity</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;of system hardware and software and begun to evaluate home system use in appropriate users. These developments have resulted in prototype systems for every day use in people's homes.</span></p>10aAnimals10aBrain10aElectroencephalography10aEvoked Potentials10aHumans10aNeuromuscular Diseases10aNew York10aResearch10aSwitzerland10aTherapy, Computer-Assisted10aUniversities10aUser-Computer Interface1 aVaughan, Theresa, M1 aMcFarland, Dennis, J.1 aSchalk, Gerwin1 aSarnacki, William, A1 aKrusienski, Dean, J1 aSellers, Eric, W1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1679230102084nas a2200181   4500008004100000022001400041245007900055210006900134260001200203300001400215490000700229520154400236653001101780653002101791100002101812700002101833856004801854       2005                        eng d  a1072-050200aAblation of cerebellar nuclei prevents H-reflex down-conditioning in rats.0 aAblation of cerebellar nuclei prevents Hreflex downconditioning   c05/2005  a248–2540 v123 aWhile studies of cerebellar involvement in learning and memory have described plasticity within the cerebellum, its role in acquisition of plasticity elsewhere in the CNS is largely unexplored. This study set out to determine whether the cerebellum is needed for acquisition of the spinal cord plasticity that underlies operantly conditioned decrease in the H-reflex, the electrical analog of the spinal stretch reflex. Rats in which the cerebellar output nuclei dentate and interpositus (DIN) had been ablated were exposed for 50 d to the H-reflex down-conditioning protocol. DIN ablation, which in itself had no significant long-term effect on H-reflex size, entirely prevented acquisition of a smaller H-reflex. Since previous studies show that corticospinal tract (CST) transection also prevents down-conditioning while transection of the rubrospinal tract and other major descending tracts does not, this result implies that DIN output that affects cortex is essential for generation of the CST activity that induces the spinal cord plasticity, which is, in turn, directly responsible for the smaller H-reflex. The result extends the role of the cerebellum in learning and memory to include participation in induction of plasticity elsewhere in the CNS, specifically in the spinal cord. The cerebellum might simply support processes in sensorimotor cortex or elsewhere that change the spinal cord, or the cerebellum itself might undergo plasticity similar to that occurring with vestibulo-ocular reflex (VOR) or eyeblink conditioning.10aReflex10aVestibulo-Ocular1 aChen, Xiang Yang1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1593050303537nas a2200253   4500008004100000022001400041245009500055210006900150260001200219300001200231490000800243520277200251653002903023653000803052653002703060653001303087653001403100653002403114100002603138700002603164700002403190700002103214856004803235       2005                        eng d  a1388-245700aBrain-computer interface (BCI) operation: signal and noise during early training sessions.0 aBraincomputer interface BCI operation signal and noise during ea  c01/2005  a56–620 v1163 aOBJECTIVE:
People can learn to control mu (8-12 Hz) or beta (18-25 Hz) rhythm amplitude in the electroencephalogram (EEG) recorded over sensorimotor cortex and use it to move a cursor to a target on a video screen. The recorded signal may also contain electromyogram (EMG) and other non-EEG artifacts. This study examines the presence and characteristics of EMG contamination during new users' initial brain-computer interface (BCI) training sessions, as they first attempt to acquire control over mu or beta rhythm amplitude and to use that control to move a cursor to a target.
METHODS:
In the standard one-dimensional format, a target appears along the right edge of the screen and 1s later the cursor appears in the middle of the left edge and moves across the screen at a fixed rate with its vertical movement controlled by a linear function of mu or beta rhythm amplitude. In the basic two-choice version, the target occupies the upper or lower half of the right edge. The user's task is to move the cursor vertically so that it hits the target when it reaches the right edge. The present data comprise the first 10 sessions of BCI training from each of 7 users. Their data were selected to illustrate the variations seen in EMG contamination across users.
RESULTS:
Five of the 7 users learned to change rhythm amplitude appropriately, so that the cursor hit the target. Three of these 5 showed no evidence of EMG contamination. In the other two of these 5, EMG was prominent in early sessions, and tended to be associated with errors rather than with hits. As EEG control improved over the 10 sessions, this EMG contamination disappeared. In the remaining two users, who never acquired actual EEG control, EMG was prominent in initial sessions and tended to move the cursor to the target. This EMG contamination was still detectable by Session 10.
CONCLUSIONS:
EMG contamination arising from cranial muscles is often present early in BCI training and gradually wanes. In those users who eventually acquire EEG control, early target-related EMG contamination may be most prominent for unsuccessful trials, and may reflect user frustration. In those users who never acquire EEG control, EMG may initially serve to move the cursor toward the target. Careful and comprehensive topographical and spectral analyses throughout user training are essential for detecting EMG contamination and differentiating between cursor control provided by EEG control and cursor control provided by EMG contamination.
SIGNIFICANCE:
Artifacts such as EMG are common in EEG recordings. Comprehensive spectral and topographical analyses are necessary to detect them and ensure that they do not masquerade as, or interfere with acquisition of, actual EEG-based cursor control.10abrain-computer interface10aEEG10aElectroencephalography10aLearning10amu rhythm10asensorimotor cortex1 aMcFarland, Dennis, J.1 aSarnacki, William, A.1 aVaughan, Theresa, M1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1558918402708nas a2200289   4500008004100000022001400041245010300055210006900158260001200227300001600239490000700255520184500262653002602107653001302133653001502146653002502161653001802186653001902204653002702223100001302250700002102263700002102284700001902305700002502324700002102349856004802370       2005                        eng d  a1529-240100aThe interaction of a new motor skill and an old one: H-reflex conditioning and locomotion in rats.0 ainteraction of a new motor skill and an old one Hreflex conditio  c07/2005  a6898–69060 v253 aNew and old motor skills can interfere with each other or interact in other ways. Because each skill entails a distributed pattern of activity-dependent plasticity, investigation of their interactions is facilitated by simple models. In a well characterized model of simple learning, rats and monkeys gradually change the size of the H-reflex, the electrical analog of the spinal stretch reflex. This study evaluates in normal rats the interactions of this new skill of H-reflex conditioning with the old well established skill of overground locomotion. In rats in which the soleus H-reflex elicited in the conditioning protocol (i.e., the conditioning H-reflex) had been decreased by down-conditioning, the H-reflexes elicited during the stance and swing phases of locomotion (i.e., the locomotor H-reflexes) were also smaller. Similarly, in rats in which the conditioning H-reflex had been increased by up-conditioning, the locomotor H-reflexes were also larger. Soleus H-reflex conditioning did not affect the duration, length, or right/left symmetry of the step cycle. However, the conditioned change in the stance H-reflex was positively correlated with change in the amplitude of the soleus locomotor burst, and the correlation was consistent with current estimates of the contribution of primary afferent input to the burst. Although H-reflex conditioning and locomotion did not interfere with each other, H-reflex conditioning did affect how locomotion was produced: it changed soleus burst amplitude and may have induced compensatory changes in the activity of other muscles. These results illustrate and clarify the subtlety and complexity of skill interactions. They also suggest that H-reflex conditioning might be used to improve the abnormal locomotion produced by spinal cord injury or other disorders of supraspinal control.10aH-reflex conditioning10aLearning10aLocomotion10amemory consolidation10aMotor control10aRehabilitation10aspinal cord plasticity1 aChen, Yi1 aChen, Xiang Yang1 aJakeman, Lyn, B.1 aSchalk, Gerwin1 aStokes, Bradford, T.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1603389902315nas a2200241   4500008004100000022001400041245006000055210005800115260001200173300001400185490000800199520163200207653002101839653002501860653001701885653001601902100002301918700002301941700002101964700001901985700002102004856004802025       2005                        eng d  a0165-027000aLong-term spinal reflex studies in awake behaving mice.0 aLongterm spinal reflex studies in awake behaving mice  c12/2005  a134–1430 v1493 aThe increasing availability of genetic variants of mice has facilitated studies of the roles of specific molecules in specific behaviors. The contributions of such studies could be strengthened and extended by correlation with detailed information on the patterns of motor commands throughout the course of specific behaviors in freely moving animals. Previously reported methodologies for long-term recording of electromyographic activity (EMG) in mice using implanted electrodes were designed for intermittent, but not continuous operation. This report describes the fabrication, implantation, and utilization of fine wire electrodes for continuous long-term recordings of spontaneous and nerve-evoked EMG in mice. Six mice were implanted with a tibial nerve cuff electrode and EMG electrodes in soleus and gastrocnemius muscles. Wires exited through a skin button and traveled through an armored cable to an electrical commutator. In mice implanted for 59-144 days, ongoing EMG was monitored continuously (i.e., 24 h/day, 7 days/week) by computer for 18-92 days (total intermittent recording for 25-130 days). When the ongoing EMG criteria were met, the computer applied the nerve stimulus, recorded the evoked EMG response, and determined the size of the M-response (MR) and the H-reflex (HR). It continually adjusted stimulation intensity to maintain a stable MR size. Stable recordings of ongoing EMG, MR, and HR were obtained typically 3 weeks after implantation. This study demonstrates the feasibility of long-term continuous EMG recordings in mice for addressing a variety of neurophysiological and behavioral issues.10aElectromyography10aimplanted electrodes10aMonosynaptic10aSpinal Cord1 aCarp, Jonathan, S.1 aTennissen, Ann, M.1 aChen, Xiang Yang1 aSchalk, Gerwin1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1602684802332nas a2200457   4500008004100000022001400041245009000055210006900145260001200214300001100226490000700237520103300244653000901277653003401286653002701320653002901347653003701376653001101413653001101424653001601435653000901451653001601460653001701476653001301493653001401506653002301520653002801543653002501571653002201596653002801618100001501646700001501661700002301676700002401699700001601723700001901739700002601758700002101784700002101805856004801826       2005                        eng d  a1526-632X00aPatients with ALS can use sensorimotor rhythms to operate a brain-computer interface.0 aPatients with ALS can use sensorimotor rhythms to operate a brai  c05/2005  a1775-70 v643 a<p><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">People with severe motor disabilities can maintain an acceptable quality of life if they can communicate.&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">Brain-computer interfaces</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;(BCIs), which do not depend on muscle control, can provide communication. Four people severely disabled by ALS learned to operate a BCI with EEG rhythms recorded over sensorimotor cortex. These results suggest that a sensorimotor rhythm-</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">based</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;BCI could help maintain quality of life for people with ALS.</span></p>10aAged10aAmyotrophic Lateral Sclerosis10aElectroencephalography10aEvoked Potentials, Motor10aEvoked Potentials, Somatosensory10aFemale10aHumans10aImagination10aMale10aMiddle Aged10aMotor Cortex10aMovement10aParalysis10aPhotic Stimulation10aProstheses and Implants10aSomatosensory Cortex10aTreatment Outcome10aUser-Computer Interface1 aKübler, A1 aNijboer, F1 aMellinger, Jürgen1 aVaughan, Theresa, M1 aPawelzik, H1 aSchalk, Gerwin1 aMcFarland, Dennis, J.1 aBirbaumer, Niels1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1591180901195nas a2200253   4500008004100000022001400041245009000055210006900145260001200214300001600226490000700242520044000249653002800689100001500717700001600732700001700748700002400765700001700789700001900806700002600825700002100851700002100872856004800893       2005                        eng d  a1526-632X00aPatients with ALS can use sensorimotor rhythms to operate a brain-computer interface.0 aPatients with ALS can use sensorimotor rhythms to operate a brai  c05/2005  a1775–17770 v643 aPeople with severe motor disabilities can maintain an acceptable quality of life if they can communicate. Brain-computer interfaces (BCIs), which do not depend on muscle control, can provide communication. Four people severely disabled by ALS learned to operate a BCI with EEG rhythms recorded over sensorimotor cortex. These results suggest that a sensorimotor rhythm-based BCI could help maintain quality of life for people with ALS.10aUser-Computer Interface1 aKübler, A1 aNijboer, F.1 aMellinger, J1 aVaughan, Theresa, M1 aPawelzik, H.1 aSchalk, Gerwin1 aMcFarland, Dennis, J.1 aBirbaumer, Niels1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1591180900403nas a2200109   4500008004100000245005200041210005100093260000900144100001900153700002100172856010000193       2005                        eng d00aRecording Options for Brain-Computer Interfaces0 aRecording Options for BrainComputer Interfaces  c20051 aSchalk, Gerwin1 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2005/recording-options-brain-computer-interfaces-000404nas a2200109   4500008004100000245005300041210005100094260000900145100001900154700002100173856010000194       2005                        eng d00aRecording Options for Brain-Computer Interfaces.0 aRecording Options for BrainComputer Interfaces  c20051 aSchalk, Gerwin1 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2005/recording-options-brain-computer-interfaces-102354nas a2200157   4500008004100000022001400041245011600055210006900171260001200240300001400252490000700266520182800273100002602101700002102127856004802148       2005                        eng d  a1534-432000aSensorimotor rhythm-based brain-computer interface (BCI): feature selection by regression improves performance.0 aSensorimotor rhythmbased braincomputer interface BCI feature sel  c09/2005  a372–3790 v133 aPeople can learn to control electroencephalogram (EEG) features consisting of sensorimotor rhythm amplitudes and can use this control to move a cursor in one or two dimensions to a target on a screen. In the standard one-dimensional application, the cursor moves horizontally from left to right at a fixed rate while vertical cursor movement is continuously controlled by sensorimotor rhythm amplitude. The right edge of the screen is divided among 2-6 targets, and the user's goal is to control vertical cursor movement so that the cursor hits the correct target when it reaches the right edge. Up to the present, vertical cursor movement has been a linear function of amplitude in a specific frequency band [i.e., 8-12 Hz (mu) or 18-26 Hz (beta)] over left and/or right sensorimotor cortex. The present study evaluated the effect of controlling cursor movement with a weighted combination of these amplitudes in which the weights were determined by an regression algorithm on the basis of the user's past performance. Analyses of data obtained from a representative set of trained users indicated that weighted combinations of sensorimotor rhythm amplitudes could support cursor control significantly superior to that provided by a single feature. Inclusion of an interaction term further improved performance. Subsequent online testing of the regression algorithm confirmed the improved performance predicted by the offline analyses. The results demonstrate the substantial value for brain-computer interface applications of simple multivariate linear algorithms. In contrast to many classification algorithms, such linear algorithms can easily incorporate multiple signal features, can readily adapt to changes in the user's control of these features, and can accommodate additional targets without major modifications.1 aMcFarland, Dennis, J.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1620076000585nas a2200157   4500008004100000245008000041210006900121260000900190100001900199700001900218700001300237700001600250700001700266700002100283856012300304       2005                        eng d00aTowards two-dimensional cursor control using electrocorticographic signals.0 aTowards twodimensional cursor control using electrocorticographi  c20051 aSchalk, Gerwin1 aLeuthardt, E C1 aMoran, D1 aMiller, K J1 aOjemann, J G1 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2005/towards-two-dimensional-cursor-control-using-electrocorticographic-000561nas a2200145   4500008004100000245007900041210006900120100001900189700001900208700001300227700001600240700001700256700002100273856012100294       2005                        eng d00aTowards two-dimensional cursor control using electrocorticographic signals0 aTowards twodimensional cursor control using electrocorticographi1 aSchalk, Gerwin1 aLeuthardt, E C1 aMoran, D1 aMiller, K J1 aOjemann, J G1 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2005/towards-two-dimensional-cursor-control-using-electrocorticographic00534nas a2200133   4500008004100000245007400041210006900115260001200184100002400196700001900220700002600239700002100265856011400286       2005                        eng d00aTracking of the mu rhythm using an empirically derived matched filter0 aTracking of the mu rhythm using an empirically derived matched f  c03/20051 aKrusienski, Dean, J1 aSchalk, Gerwin1 aMcFarland, Dennis, J.1 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2005/tracking-mu-rhythm-using-empirically-derived-matched-filter01351nas a2200409   4500008004100000020001800041245007500059210006900134260003300203653002700236653003000263653001900293653002900312653002500341653003300366653003400399653000800433653002700441653003900468653002100507653001700528653002000545653002900565653003000594653001500624653001800639653002300657653002600680653001100706653002300717653004000740100002400780700001900804700002600823700002100849856007100870       2005                        eng d  a0-7803-8710-400aTracking of the mu rhythm using an empirically derived matched filter.0 aTracking of the mu rhythm using an empirically derived matched f  aArlington, VAbIEEEc03/200510abioelectric potentials10aBrain Computer Interfaces10abrain modeling10abrain-computer interface10acommunication device10acommunication system control10acortical mu rhythm modulation10aEEG10aElectroencephalography10aempirically derived matched filter10ahandicapped aids10alaboratories10amatched filters10amedical signal detection10amedical signal processing10amonitoring10amotor imagery10amu rhythm tracking10anoninvasive treatment10arhythm10asynchronous motors10atwo-dimensional cursor control data1 aKrusienski, Dean, J1 aSchalk, Gerwin1 aMcFarland, Dennis, J.1 aWolpaw, Jonathan  uhttp://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=141955902685nas a2200433   4500008004100000022001400041245011000055210006900165260001200234300001600246490000700262520140200269653003101671653000801702653001601710653002901726653000801755653000801763653002801771653003601799653001401835653000901849653001901858653003201877653002901909100002401938700002601962700001901988700002402007700001902031700002102050700002002071700002002091700002402111700002402135700002302159700002102182856004802203       2004                        eng d  a0018-929400aThe BCI Competition 2003: progress and perspectives in detection and discrimination of EEG single trials.0 aBCI Competition 2003 progress and perspectives in detection and   c06/2004  a1044–10510 v513 aInterest in developing a new method of man-to-machine communication–a brain-computer interface (BCI)–has grown steadily over the past few decades. BCIs create a new communication channel between the brain and an output device by bypassing conventional motor output pathways of nerves and muscles. These systems use signals recorded from the scalp, the surface of the cortex, or from inside the brain to enable users to control a variety of applications including simple word-processing software and orthotics. BCI technology could therefore provide a new communication and control option for individuals who cannot otherwise express their wishes to the outside world. Signal processing and classification methods are essential tools in the development of improved BCI technology. We organized the BCI Competition 2003 to evaluate the current state of the art of these tools. Four laboratories well versed in EEG-based BCI research provided six data sets in a documented format. We made these data sets (i.e., labeled training sets and unlabeled test sets) and their descriptions available on the Internet. The goal in the competition was to maximize the performance measure for the test labels. Researchers worldwide tested their algorithms and competed for the best classification results. This paper describes the six data sets and the results and function of the most successful algorithms.10aaugmentative communication10aBCI10abeta-rhythm10abrain-computer interface10aEEG10aERP10aimagined hand movements10alateralized readiness potential10amu-rhythm10aP30010aRehabilitation10asingle-trial classification10aslow cortical potentials1 aBlankertz, Benjamin1 aMüller, Klaus-Robert1 aCurio, Gabriel1 aVaughan, Theresa, M1 aSchalk, Gerwin1 aWolpaw, Jonathan1 aSchlögl, Alois1 aNeuper, Christa1 aPfurtscheller, Gert1 aHinterberger, Thilo1 aSchröder, Michael1 aBirbaumer, Niels  uhttp://www.ncbi.nlm.nih.gov/pubmed/1518887602760nas a2200433   4500008004100000022001400041245011000055210006900165260001200234300001200246490000700258520140000265653001001665653001501675653003401690653002801724653001001752653001401762653002301776653002701799653002201826653001101848653003101859653003201890653002801922100002401950700002601974700001902000700002402019700001902043700002102062700002002083700002002103700002402123700002002147700002302167700002102190856011502211       2004                        eng d  a0018-929400aThe BCI Competition 2003: Progress and perspectives in detection and discrimination of EEG single trials.0 aBCI Competition 2003 Progress and perspectives in detection and   c06/2004  a1044-510 v513 aInterest in developing a new method of man-to-machine communication--a brain-computer interface (BCI)--has grown steadily over the past few decades. BCIs create a new communication channel between the brain and an output device by bypassing conventional motor output pathways of nerves and muscles. These systems use signals recorded from the scalp, the surface of the cortex, or from inside the brain to enable users to control a variety of applications including simple word-processing software and orthotics. BCI technology could therefore provide a new communication and control option for individuals who cannot otherwise express their wishes to the outside world. Signal processing and classification methods are essential tools in the development of improved BCI technology. We organized the BCI Competition 2003 to evaluate the current state of the art of these tools. Four laboratories well versed in EEG-based BCI research provided six data sets in a documented format. We made these data sets (i.e., labeled training sets and unlabeled test sets) and their descriptions available on the Internet. The goal in the competition was to maximize the performance measure for the test labels. Researchers worldwide tested their algorithms and competed for the best classification results. This paper describes the six data sets and the results and function of the most successful algorithms.10aAdult10aAlgorithms10aAmyotrophic Lateral Sclerosis10aArtificial Intelligence10aBrain10aCognition10aDatabases, Factual10aElectroencephalography10aEvoked Potentials10aHumans10aReproducibility of Results10aSensitivity and Specificity10aUser-Computer Interface1 aBlankertz, Benjamin1 aMüller, Klaus-Robert1 aCurio, Gabriel1 aVaughan, Theresa, M1 aSchalk, Gerwin1 aWolpaw, Jonathan1 aSchlögl, Alois1 aNeuper, Christa1 aPfurtscheller, Gert1 aHinterberger, T1 aSchröder, Michael1 aBirbaumer, Niels  uhttps://www.neurotechcenter.org/publications/2004/bci-competition-2003-progress-and-perspectives-detection-and02279nas a2200205   4500008004100000022001400041245007000055210006400125260001200189300001600201490000700217520166200224653002801886100001901914700002601933700002401959700002101983700002102004856004802025       2004                        eng d  a0018-929400aBCI2000: a general-purpose brain-computer interface (BCI) system.0 aBCI2000 a generalpurpose braincomputer interface BCI system  c06/2004  a1034–10430 v513 aMany laboratories have begun to develop brain-computer interface (BCI) systems that provide communication and control capabilities to people with severe motor disabilities. Further progress and realization of practical applications depends on systematic evaluations and comparisons of different brain signals, recording methods, processing algorithms, output formats, and operating protocols. However, the typical BCI system is designed specifically for one particular BCI method and is, therefore, not suited to the systematic studies that are essential for continued progress. In response to this problem, we have developed a documented general-purpose BCI research and development platform called BCI2000. BCI2000 can incorporate alone or in combination any brain signals, signal processing methods, output devices, and operating protocols. This report is intended to describe to investigators, biomedical engineers, and computer scientists the concepts that the BC12000 system is based upon and gives examples of successful BCI implementations using this system. To date, we have used BCI2000 to create BCI systems for a variety of brain signals, processing methods, and applications. The data show that these systems function well in online operation and that BCI2000 satisfies the stringent real-time requirements of BCI systems. By substantially reducing labor and cost, BCI2000 facilitates the implementation of different BCI systems and other psychophysiological experiments. It is available with full documentation and free of charge for research or educational purposes and is currently being used in a variety of studies by many research groups.10aUser-Computer Interface1 aSchalk, Gerwin1 aMcFarland, Dennis, J.1 aHinterberger, Thilo1 aBirbaumer, Niels1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1518887502705nas a2200337   4500008004100000022001400041245007000055210006400125260001200189300001200201490000700213520166200220653001501882653001001897653001401907653003601921653002501957653002701982653002102009653003102030653002202061653001102083653002402094653002802118100001902146700002602165700002002191700002102211700002102232856011402253       2004                        eng d  a0018-929400aBCI2000: a general-purpose brain-computer interface (BCI) system.0 aBCI2000 a generalpurpose braincomputer interface BCI system  c06/2004  a1034-430 v513 aMany laboratories have begun to develop brain-computer interface (BCI) systems that provide communication and control capabilities to people with severe motor disabilities. Further progress and realization of practical applications depends on systematic evaluations and comparisons of different brain signals, recording methods, processing algorithms, output formats, and operating protocols. However, the typical BCI system is designed specifically for one particular BCI method and is, therefore, not suited to the systematic studies that are essential for continued progress. In response to this problem, we have developed a documented general-purpose BCI research and development platform called BCI2000. BCI2000 can incorporate alone or in combination any brain signals, signal processing methods, output devices, and operating protocols. This report is intended to describe to investigators, biomedical engineers, and computer scientists the concepts that the BC12000 system is based upon and gives examples of successful BCI implementations using this system. To date, we have used BCI2000 to create BCI systems for a variety of brain signals, processing methods, and applications. The data show that these systems function well in online operation and that BCI2000 satisfies the stringent real-time requirements of BCI systems. By substantially reducing labor and cost, BCI2000 facilitates the implementation of different BCI systems and other psychophysiological experiments. It is available with full documentation and free of charge for research or educational purposes and is currently being used in a variety of studies by many research groups.10aAlgorithms10aBrain10aCognition10aCommunication Aids for Disabled10aComputer Peripherals10aElectroencephalography10aEquipment Design10aEquipment Failure Analysis10aEvoked Potentials10aHumans10aSystems Integration10aUser-Computer Interface1 aSchalk, Gerwin1 aMcFarland, Dennis, J.1 aHinterberger, T1 aBirbaumer, Niels1 aWolpaw, Jonathan  uhttps://www.neurotechcenter.org/publications/2004/bci2000-general-purpose-brain-computer-interface-bci-system03554nas a2200361   4500008004100000022001400041245007800055210006900133260001200202300001000214490000600224520253800230653001002768653001002778653003602788653002502824653003302849653002602882653002702908653002202935653001102957653001102968653001602979653000902995653002303004653002803027100001903055700001903074700002103093700001703114700001303131856004803144       2004                        eng d  a1741-256000aA brain-computer interface using electrocorticographic signals in humans.0 abraincomputer interface using electrocorticographic signals in h  c06/2004  a63-710 v13 a<p><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">Brain-computer interfaces</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;(BCIs) enable users to control devices with electroencephalographic (EEG) activity from the scalp or with single-neuron activity from within the&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">brain</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">. Both methods have disadvantages: EEG has limited resolution and requires extensive training, while single-neuron recording entails significant clinical risks and has limited stability. We demonstrate here for the first time that electrocorticographic (ECoG) activity recorded from the surface of the&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">brain</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;can enable users to control a one-dimensional&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">computer</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;cursor rapidly and accurately. We first identified ECoG signals that were associated with different types of motor and speech imagery. Over brief training periods of 3-24 min, four patients then used these signals to master closed-loop control and to achieve success rates of 74-100% in a one-dimensional binary task. In additional open-loop experiments, we found that ECoG signals at frequencies up to 180 Hz encoded substantial information about the direction of two-dimensional joystick movements. Our results suggest that an ECoG-based BCI could provide for people with severe motor disabilities a non-muscular communication and control option that is more powerful than EEG-based BCIs and is potentially more stable and less traumatic than BCIs that use electrodes penetrating the&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">brain</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">.</span></p>10aAdult10aBrain10aCommunication Aids for Disabled10aComputer Peripherals10aDiagnosis, Computer-Assisted10aElectrodes, Implanted10aElectroencephalography10aEvoked Potentials10aFemale10aHumans10aImagination10aMale10aMovement Disorders10aUser-Computer Interface1 aLeuthardt, E C1 aSchalk, Gerwin1 aWolpaw, Jonathan1 aOjemann, J G1 aMoran, D  uhttp://www.ncbi.nlm.nih.gov/pubmed/1587662400581nas a2200169   4500008004100000022001400041245008300055210006900138260001200207300001400219490000700233653004300240653003000283653002900313100002100342856004800363       2004                        eng d  a1567-424X00aBrain-computer interfaces (BCIs) for communication and control: a mini-review.0 aBraincomputer interfaces BCIs for communication and control a mi  c02/2004  a607–6130 v5710aaugmentative communication and control10abrain-computer interfaces10aneuro-muscular disorders1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1610666201886nas a2200181   4500008004100000022001400041245010200055210006900157260001200226300001800238490000800256520129000264653002801554653002701582100002101609700002601630856004801656       2004                        eng d  a0027-842400aControl of a two-dimensional movement signal by a noninvasive brain-computer interface in humans.0 aControl of a twodimensional movement signal by a noninvasive bra  c12/2004  a17849–178540 v1013 aBrain-computer interfaces (BCIs) can provide communication and control to people who are totally paralyzed. BCIs can use noninvasive or invasive methods for recording the brain signals that convey the user's commands. Whereas noninvasive BCIs are already in use for simple applications, it has been widely assumed that only invasive BCIs, which use electrodes implanted in the brain, can provide multidimensional movement control of a robotic arm or a neuroprosthesis. We now show that a noninvasive BCI that uses scalp-recorded electroencephalographic activity and an adaptive algorithm can provide humans, including people with spinal cord injuries, with multidimensional point-to-point movement control that falls within the range of that reported with invasive methods in monkeys. In movement time, precision, and accuracy, the results are comparable to those with invasive BCIs. The adaptive algorithm used in this noninvasive BCI identifies and focuses on the electroencephalographic features that the person is best able to control and encourages further improvement in that control. The results suggest that people with severe motor disabilities could use brain signals to operate a robotic arm or a neuroprosthesis without needing to have electrodes implanted in their brains.10abrain-machine interface10aElectroencephalography1 aWolpaw, Jonathan1 aMcFarland, Dennis, J.  uhttp://www.ncbi.nlm.nih.gov/pubmed/1558558402353nas a2200229   4500008004100000022001400041245008900055210006900144260001200213300001400225490000700239520162900246653003101875653003501906653002701941653001301968100002301981700002602004700002102030700002402051856004802075       2004                        eng d  a1534-432000aConversion of EEG activity into cursor movement by a brain-computer interface (BCI).0 aConversion of EEG activity into cursor movement by a braincomput  c09/2004  a331–3380 v123 aThe Wadsworth electroencephalogram (EEG)-based brain-computer interface (BCI) uses amplitude in mu or beta frequency bands over sensorimotor cortex to control cursor movement. Trained users can move the cursor in one or two dimensions. The primary goal of this research is to provide a new communication and control option for people with severe motor disabilities. Currently, cursor movements in each dimension are determined 10 times/s by an empirically derived linear function of one or two EEG features (i.e., spectral bands from different electrode locations). This study used offline analysis of data collected during system operation to explore methods for improving the accuracy of cursor movement. The data were gathered while users selected among three possible targets by controlling vertical [i.e., one-dimensional (1-D)] cursor movement. The three methods analyzed differ in the dimensionality of the cursor movement [1-D versus two-dimensional (2-D)] and in the type of the underlying function (linear versus nonlinear). We addressed two questions: Which method is best for classification (i.e., to determine from the EEG which target the user wants to hit)? How does the number of EEG features affect the performance of each method? All methods reached their optimal performance with 10-20 features. In offline simulation, the 2-D linear method and the 1-D nonlinear method improved performance significantly over the 1-D linear method. The 1-D linear method did not do so. These offline results suggest that the 1-D nonlinear or the 2-D linear cursor function will improve online operation of the BCI system.10aaugmentative communication10aBrain-computer interface (BCI)10aElectroencephalography10aFeedback1 aFabiani, Georg, E.1 aMcFarland, Dennis, J.1 aWolpaw, Jonathan1 aPfurtscheller, Gert  uhttp://www.ncbi.nlm.nih.gov/pubmed/1547319500690nas a2200181   4500008004100000245009300041210006900134100002300203700001500226700001600241700001900257700002600276700002400302700002100326700002100347700001500368856012500383       2004                        eng d00aP300 for communication: Evidence from patients with amyotrophic lateral sclerosis (ALS).0 aP300 for communication Evidence from patients with amyotrophic l1 aMellinger, Jürgen1 aNijboer, F1 aPawelzik, H1 aSchalk, Gerwin1 aMcFarland, Dennis, J.1 aVaughan, Theresa, M1 aWolpaw, Jonathan1 aBirbaumer, Niels1 aKuebler, A  uhttps://www.neurotechcenter.org/publications/2004/p300-communication-evidence-patients-amyotrophic-lateral-sclerosis-als02522nas a2200277   4500008004100000022001400041245008500055210006900140260001200209300001400221490000700235520169700242653003101939653002701970653001601997653001302013653001402026653002502040653001502065653001902080653002402099100002602123700002602149700002102175856004802196       2003                        eng d  a0301-051100aBrain-computer interface (BCI) operation: optimizing information transfer rates.0 aBraincomputer interface BCI operation optimizing information tra  c07/2003  a237–2510 v633 aPeople can learn to control mu (8-12 Hz) or beta (18-25 Hz) rhythm amplitude in the EEG recorded over sensorimotor cortex and use it to move a cursor to a target on a video screen. In the present version of the cursor movement task, vertical cursor movement is a linear function of mu or beta rhythm amplitude. At the same time the cursor moves horizontally from left to right at a fixed rate. A target occupies 50% (2-target task) to 20% (5-target task) of the right edge of the screen. The user's task is to move the cursor vertically so that it hits the target when it reaches the right edge. The goal of the present study was to optimize system performance. To accomplish this, we evaluated the impact on system performance of number of targets (i.e. 2-5) and trial duration (i.e. horizontal movement time from 1 to 4 s). Performance was measured as accuracy (percent of targets selected correctly) and also as bit rate (bits/min) (which incorporates, in addition to accuracy, speed and the number of possible targets). Accuracy declined as target number increased. At the same time, for six of eight users, four targets yielded the maximum bit rate. Accuracy increased as movement time increased. At the same time, the movement time with the highest bit rate varied across users from 2 to 4 s. These results indicate that task parameters such as target number and trial duration can markedly affect system performance. They also indicate that optimal parameter values vary across users. Selection of parameters suited both to the specific user and the requirements of the specific application is likely to be a key factor in maximizing the success of EEG-based communication and control.10aaugmentative communication10aElectroencephalography10ainformation10aLearning10amu rhythm10aoperant conditioning10aprosthesis10aRehabilitation10asensorimotor cortex1 aMcFarland, Dennis, J.1 aSarnacki, William, A.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1285316902907nas a2200325   4500008004100000022001400041245008700055210006900142260001200211300001300223490000700236520189600243653003102139653003502170653003302205653001902238100002402257700002702281700002302308700002302331700002202354700002202376700002002398700002202418700002102440700002102461700003002482700002102512856004802533       2003                        eng d  a1534-432000aBrain-computer interface technology: a review of the Second International Meeting.0 aBraincomputer interface technology a review of the Second Intern  c06/2003  a94–1090 v113 aThis paper summarizes the Brain-Computer Interfaces for Communication and Control, The Second International Meeting, held in Rensselaerville, NY, in June 2002. Sponsored by the National Institutes of Health and organized by the Wadsworth Center of the New York State Department of Health, the meeting addressed current work and future plans in brain-computer interface (BCI) research. Ninety-two researchers representing 38 different research groups from the United States, Canada, Europe, and China participated. The BCIs discussed at the meeting use electroencephalographic activity recorded from the scalp or single-neuron activity recorded within cortex to control cursor movement, select letters or icons, or operate neuroprostheses. The central element in each BCI is a translation algorithm that converts electrophysiological input from the user into output that controls external devices. BCI operation depends on effective interaction between two adaptive controllers, the user who encodes his or her commands in the electrophysiological input provided to the BCI, and the BCI that recognizes the commands contained in the input and expresses them in device control. Current BCIs have maximum information transfer rates of up to 25 b/min. Achievement of greater speed and accuracy requires improvements in signal acquisition and processing, in translation algorithms, and in user training. These improvements depend on interdisciplinary cooperation among neuroscientists, engineers, computer programmers, psychologists, and rehabilitation specialists, and on adoption and widespread application of objective criteria for evaluating alternative methods. The practical use of BCI technology will be determined by the development of appropriate applications and identification of appropriate user groups, and will require careful attention to the needs and desires of individual users.10aaugmentative communication10aBrain-computer interface (BCI)10aelectroencephalography (EEG)10aRehabilitation1 aVaughan, Theresa, M1 aHeetderks, William, J.1 aTrejo, Leonard, J.1 aRymer, William, Z.1 aWeinrich, Michael1 aMoore, Melody, M.1 aKübler, Andrea1 aDobkin, Bruce, H.1 aBirbaumer, Niels1 aDonchin, Emanuel1 aWolpaw, Elizabeth, Winter1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1289924702534nas a2200181   4500008004100000022001400041245010200055210006900157260001200226300001600238490000700254520196300261653002502224100002102249700001302270700002102283856004802304       2003                        eng d  a0022-307700aConditioned H-reflex increase persists after transection of the main corticospinal tract in rats.0 aConditioned Hreflex increase persists after transection of the m  c11/2003  a3572–35780 v903 aThe brain shapes spinal cord function throughout life. Operant conditioning of the H-reflex, the electrical analog of the spinal stretch reflex (SSR), is a relatively simple model for exploring the spinal cord plasticity underlying this functional change and may provide a new method for modifying spinal cord reflexes after spinal cord injury. In response to an operant conditioning protocol, rats can gradually increase (i.e., up-training mode) or decrease (i.e., down-training mode) the soleus H-reflex. This study explored the effects of midthoracic transection of the ipsilateral lateral column (LC) (rubrospinal, vestibulospinal, and reticulospinal tracts), the dorsal column corticospinal tract (CST), or the dorsal column ascending tract (DA) on maintenance of an H-reflex increase that has already occurred. Rats were implanted with EMG electrodes in the right soleus muscle and a nerve-stimulating cuff on the right posterior tibial nerve. After initial (i.e., control) H-reflex size was determined, the rats were exposed for 50 days to the up-training mode, in which reward was given when the H-reflex was above a criterion value. H-reflex size gradually rose to 168 +/- 12% (mean +/- SE) of its initial value. Each rat then received an LC, CST, or DA transection and continued under the up-training mode for 50 more days. None of the transections abolished the H-reflex increase. H-reflex size increased further to 197 +/- 19% of its initial value and did not differ significantly among LC, CST, and DA rats (P > 0.78 by ANOVA). Although earlier studies show that the main CST is needed for acquisition of H-reflex up-training and down-training and for maintenance of down-training, this study shows that it is not needed for maintenance of up-training. It adds to the evidence that H-reflex conditioning changes the spinal cord and that the spinal cord plasticity associated with up-training is different from that associated with down-training.10aSpinal Cord Injuries1 aChen, Xiang Yang1 aChen, Lu1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1291738201648nas a2200229   4500008004100000022001400041245010000055210006900155260001200224300001400236490000800250520093900258653002101197653002401218653002701242653002001269653001401289100002301303700002301326700002101349856004801370       2003                        eng d  a0014-481900aConduction velocity is inversely related to action potential threshold in rat motoneuron axons.0 aConduction velocity is inversely related to action potential thr  c06/2003  a497–5050 v1503 aIntra-axonal recordings were performed in ventral roots of rats in vitro to study the conduction velocity and firing threshold properties of motoneuron axons. Mean values +/- SD were 30.5+/-5.6 m/s for conduction velocity and 11.6+/-4.5 mV for the depolarization from the resting potential required to reach firing threshold (threshold depolarization). Conduction velocity varied inversely and significantly with threshold depolarization ( P=0.0002 by linear regression). This relationship was evident even after accounting for variation in conduction velocity associated with action potential amplitude, injected current amplitude, or body weight. Conduction velocity also varied inversely with the time to action potential onset during just-threshold current pulse injection. These data suggest that the time course of depolarization leading to action potential initiation contributes to the speed of conduction in motoneuron axons.10aaction potential10aconduction velocity10aintra-axonal recording10amyelinated axon10athreshold1 aCarp, Jonathan, S.1 aTennissen, Ann, M.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1271511802255nas a2200169   4500008004100000022001400041245007100055210006700126260001200193300001400205490000700219520174400226653002001970100002601990700002102016856004802037       2003                        eng d  a1090-058600aEEG-based communication and control: speed-accuracy relationships.0 aEEGbased communication and control speedaccuracy relationships  c09/2003  a217–2310 v283 aPeople can learn to control mu (8-12 Hz) or beta (18-25 Hz) rhythm amplitude in the EEG recorded over sensorimotor cortex and use it to move a cursor to a target on a video screen. In our current EEG-based brain-computer interface (BCI) system, cursor movement is a linear function of mu or beta rhythm amplitude. In order to maximize the participant's control over the direction of cursor movement, the intercept in this equation is kept equal to the mean amplitude of recent performance. Selection of the optimal slope, or gain, which determines the magnitude of the individual cursor movements, is a more difficult problem. This study examined the relationship between gain and accuracy in a 1-dimensional EEG-based cursor movement task in which individuals select among 2 or more choices by holding the cursor at the desired choice for a fixed period of time (i.e., the dwell time). With 4 targets arranged in a vertical column on the screen, large gains favored the end targets whereas smaller gains favored the central targets. In addition, manipulating gain and dwell time within participants produces results that are in agreement with simulations based on a simple theoretical model of performance. Optimal performance occurs when correct selection of targets is uniform across position. Thus, it is desirable to remove any trend in the function relating accuracy to target position. We evaluated a controller that is designed to minimize the linear and quadratic trends in the accuracy with which participants hit the 4 targets. These results indicate that gain should be adjusted to the individual participants, and suggest that continual online gain adaptation could increase the speed and accuracy of EEG-based cursor control.10aVideo Recording1 aMcFarland, Dennis, J.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1296445301629nas a2200265   4500008004100000022001400041245010300055210006900158260001200227300001200239490000800251520078600259653003101045653002901076653002801105653002701133653002401160653002001184653001901204100001901223700002601242700002601268700002101294856004801315       2003                        eng d  a0304-394000aElectroencephalographic(EEG)-based communication: EEG control versus system performance in humans.0 aElectroencephalographicEEGbased communication EEG control versus  c07/2002  a89–920 v3453 aPeople can learn to control electroencephalographic (EEG) sensorimotor rhythm amplitude so as to move a cursor to select among choices on a computer screen. We explored the dependence of system performance on EEG control. Users moved the cursor to reach a target at one of four possible locations. EEG control was measured as the correlation (r(2)) between rhythm amplitude and target location. Performance was measured as accuracy (% of targets hit) and as information transfer rate (bits/trial). The relationship between EEG control and accuracy can be approximated by a linear function that is constant for all users. The results facilitate offline predictions of the effects on performance of using different EEG features or combinations of features to control cursor movement.10aaugmentative communication10abrain-computer interface10abrain-machine interface10aElectroencephalography10amu and beta rhythms10aneuroprosthesis10aRehabilitation1 aSheikh, Hesham1 aMcFarland, Dennis, J.1 aSarnacki, William, A.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1282117802517nas a2200241   4500008004100000022001400041245007400055210006900129260001200198300001600210490000800226520179400234653001302028653002902041653002502070653001902095653001902114100002302133700002602156700002402182700002102206856004802227       2003                        eng d  a1388-245700aEMG contamination of EEG: spectral and topographical characteristics.0 aEMG contamination of EEG spectral and topographical characterist  c09/2003  a1580–15930 v1143 aOBJECTIVE:
Electromyogram (EMG) contamination is often a problem in electroencephalogram (EEG) recording, particularly, for those applications such as EEG-based brain-computer interfaces that rely on automated measurements of EEG features. As an essential prelude to developing methods for recognizing and eliminating EMG contamination of EEG, this study defines the spectral and topographical characteristics of frontalis and temporalis muscle EMG over the entire scalp. It describes both average data and the range of individual differences.
METHODS:
In 25 healthy adults, signals from 64 scalp and 4 facial locations were recorded during relaxation and during defined (15, 30, or 70% of maximum) contractions of frontalis or temporalis muscles.
RESULTS:
In the average data, EMG had a broad frequency distribution from 0 to >200 Hz. Amplitude was greatest at 20-30 Hz frontally and 40-80 Hz temporally. Temporalis spectra also showed a smaller peak around 20 Hz. These spectral components attenuated and broadened centrally. Even with weak (15%) contraction, EMG was detectable (P<0.001) near the vertex at frequencies >12 Hz in the average data and >8 Hz in some individuals.
CONCLUSIONS:
Frontalis or temporalis muscle EMG recorded from the scalp has spectral and topographical features that vary substantially across individuals. EMG spectra often have peaks in the beta frequency range that resemble EEG beta peaks.
SIGNIFICANCE:
While EMG contamination is greatest at the periphery of the scalp near the active muscles, even weak contractions can produce EMG that obscures or mimics EEG alpha, mu, or beta rhythms over the entire scalp. Recognition and elimination of this contamination is likely to require recording from an appropriate set of peripheral scalp locations.10aartifact10abrain-computer interface10aelectroencephalogram10aelectromyogram10aRehabilitation1 aGoncharova, I., I.1 aMcFarland, Dennis, J.1 aVaughan, Theresa, M1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1294878703064nas a2200373   4500008004100000022001400041245009000055210006900145260001200214300001000226490000700236520200500243653002902248653001002277653001502287653001402302653001002316653001802326653002702344653003002371653001302401653001102414653001602425653002802441653001302469653002002482653002802502653002202530100002102552700002602573700002402599700001902623856004802642       2003                        eng d  a1534-432000aThe Wadsworth Center brain-computer interface (BCI) research and development program.0 aWadsworth Center braincomputer interface BCI research and develo  c06/2003  a204-70 v113 a<p><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">Brain-computer interface (BCI) research at the Wadsworth Center has focused primarily on using electroencephalogram (EEG) rhythms recorded from the scalp over sensorimotor cortex to&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">control</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;cursor movement in one or two dimensions. Recent and current studies seek to improve the speed and accuracy of this&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">control</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;by improving the selection of signal features and their translation into device commands, by incorporating additional signal features, and by optimizing the adaptive interaction between the user and system. In addition, to facilitate the evaluation, comparison, and combination of alternative BCI methods, we have developed a general-purpose BCI system called BCI-2000 and have made it available to other research&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">groups</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">. Finally, in collaboration with several other&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">groups</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">, we are developing simple BCI applications and are testing their practicality and long-term value for people with severe motor disabilities.</span></p>10aAcademic Medical Centers10aAdult10aAlgorithms10aArtifacts10aBrain10aBrain Mapping10aElectroencephalography10aEvoked Potentials, Visual10aFeedback10aHumans10aMiddle Aged10aNervous System Diseases10aResearch10aResearch Design10aUser-Computer Interface10aVisual Perception1 aWolpaw, Jonathan1 aMcFarland, Dennis, J.1 aVaughan, Theresa, M1 aSchalk, Gerwin  uhttp://www.ncbi.nlm.nih.gov/pubmed/1289927506596nas a2200265   4500008004100000022001400041245006100055210005900116260001200175300001100187490000800198520581800206653001906024653003606043653002106079653002706100653001106127653002806138100002106166700002106187700002606208700002406234700002406258856004806282       2002                        eng d  a1388-245700aBrain-computer interfaces for communication and control.0 aBraincomputer interfaces for communication and control  c06/2002  a767-910 v1133 a<p><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">For many years people have speculated that electroencephalographic activity or other electrophysiological measures of brain function might provide a new non-muscular channel for sending messages and commands to the external world - a brain-computer interface (BCI). Over the past 15 years, productive BCI research programs have arisen. Encouraged by new understanding of brain function, by the advent of powerful low-cost computer equipment, and by growing recognition of the needs and potentials of people with disabilities, these programs concentrate on developing new augmentative communication and&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">control</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">technology for those with severe neuromuscular disorders, such as amyotrophic lateral sclerosis, brainstem stroke, and spinal cord injury. The immediate goal is to provide these users, who may be completely paralyzed, or 'locked in', with basic communication capabilities so that they can express their wishes to caregivers or even operate word processing programs or neuroprostheses. Present-day BCIs determine the intent of the user from a variety of different electrophysiological signals. These signals include slow cortical potentials, P300 potentials, and mu or beta rhythms recorded from the scalp, and cortical neuronal activity recorded by implanted electrodes. They are translated in real-time into commands that operate a computer display or other device. Successful operation requires that the user encode commands in these signals and that the BCI derive the commands from the signals. Thus, the user and the BCI system need to adapt to each other both initially and continually so as to ensure stable performance. Current BCIs have maximum information transfer rates up to 10-25bits/min. This limited capacity can be valuable for people whose severe disabilities prevent them from using conventional augmentative communication methods. At the same time, many possible applications of BCI technology, such as neuroprosthesis&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">control</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">, may require higher information transfer rates. Future progress will depend on: recognition that BCI research and development is an interdisciplinary problem, involving neurobiology, psychology, engineering, mathematics, and computer science; identification of those signals, whether evoked potentials, spontaneous rhythms, or neuronal firing rates, that users are best able to&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">control</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;independent of activity in conventional motor output pathways; development of training methods for helping users to gain and maintain that&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">control</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">; delineation of the best algorithms for translating these signals into device commands; attention to the identification and elimination of artifacts such as electromyographic and electro-oculographic activity; adoption of precise and objective procedures for evaluating BCI performance; recognition of the need for long-term as well as short-term assessment of BCI performance; identification of appropriate BCI applications and appropriate matching of applications and users; and attention to factors that affect user acceptance of augmentative technology, including ease of use, cosmesis, and provision of those communication and&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">control</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;capacities that are most important to the user. Development of BCI technology will also benefit from greater emphasis on peer-reviewed research publications and avoidance of the hyperbolic and often misleading media attention that tends to generate unrealistic expectations in the public and skepticism in other researchers. With adequate recognition and effective engagement of all these issues, BCI systems could eventually provide an important new communication and&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">control</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;option for those with motor disabilities and might also give those without disabilities a supplementary&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">control</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;channel or a&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">control</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;channel useful in special circumstances.</span></p>10aBrain Diseases10aCommunication Aids for Disabled10aComputer Systems10aElectroencephalography10aHumans10aUser-Computer Interface1 aWolpaw, Jonathan1 aBirbaumer, Niels1 aMcFarland, Dennis, J.1 aPfurtscheller, Gert1 aVaughan, Theresa, M  uhttp://www.ncbi.nlm.nih.gov/pubmed/1204803802878nas a2200241   4500008004100000022001400041245009400055210006900149260001200218300001200230490000800242520217200250653001802422653001902440653001302459653001502472653002302487100002102510700002302531700001302554700002102567856004802588       2002                        eng d  a0014-481900aCorticospinal tract transection prevents operantly conditioned H-reflex increase in rats.0 aCorticospinal tract transection prevents operantly conditioned H  c05/2002  a88–940 v1443 aOperant conditioning of the H-reflex, the electrical analog of the spinal stretch reflex, in freely moving rats is a relatively simple model for studying long-term supraspinal control over spinal cord function. Motivated by food reward, rats can gradually increase (i.e., up-condition) or decrease (i.e., down-condition) the soleus H-reflex. Earlier work showed that corticospinal tract transection prevents acquisition and maintenance of H-reflex down-conditioning while transection of other major spinal cord tracts does not. This study explores the effects on acquisition of up-conditioning of the right soleus H-reflex of mid-thoracic transection of: the right lateral column (LC, five rats) (containing the rubrospinal, vestibulospinal, and reticulospinal tracts); the entire dorsal column (DC, six rats) [containing the main corticospinal tract (CST) and the dorsal ascending tract (DA)]; the CST alone (five rats); or the DA alone (seven rats). After initial (i.e., control) H-reflex amplitude was determined, the rat was exposed for 50 days to the up-conditioning mode in which reward was given when the H-reflex was above a criterion value. H-reflex amplitude at the end of up-conditioning was compared to initial H-reflex amplitude. An increase > or =20% was defined as successful up-conditioning. In intact rats, H-reflex amplitude at the end of up-conditioning averaged 164% (+/-10%, SE), and 81% were successful. In the present study, LC and DA rats were similar to intact rats in final H-reflex amplitude and percent successful. In contrast, results for DC and CST rats were significantly different from those of intact rats. In the six DC rats, final H-reflex amplitude averaged 105% (+/-3)% of control and none was successful; and in the five CST rats, final H-reflex amplitude averaged 94% (+/-3)% and none was successful. The results indicate that the main CST, located in the dorsal column, is essential for H-reflex up-conditioning as it is for down-conditioning, while the dorsal column ascending tract and the ipsilateral lateral column (containing the main rubrospinal, vestibulospinal, and reticulospinal tracts) do not appear to be essential.10adorsal column10alateral column10aLearning10aplasticity10aspinal cord injury1 aChen, Xiang Yang1 aCarp, Jonathan, S.1 aChen, Lu1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1197676201877nas a2200253   4500008004100000022001400041245007900055210006900134260001200203300001400215490000800229520115300237653002201390653002401412653001901436653001301455653000801468653002301476100002101499700001301520700002101533700002101554856004801575       2002                        eng d  a0006-899300aCorticospinal tract transection reduces H-reflex circadian rhythm in rats.0 aCorticospinal tract transection reduces Hreflex circadian rhythm  c06/2002  a101–1080 v9423 aIn freely moving rats and monkeys, H-reflex amplitude displays a marked circadian variation without change in background motoneuron tone. In rats, the H-reflex is largest around noon and smallest around midnight. The present study evaluated in rats the effects on this rhythm of calibrated contusions of mid-thoracic spinal cord and mid-thoracic transection of specific spinal cord pathways. In 33 control rats, rhythm amplitude averaged 29.0(+/-2.6 S.E.)% of H-reflex amplitude. Contusion injuries at T8-9 that destroyed 53-88% of the white matter significantly reduced the rhythm to 18.9(+/-2.4)% of H-reflex amplitude. Transection of the ipsilateral lateral column, which contains the rubrospinal, vestibulospinal, and reticulospinal tracts, or bilateral transection of the dorsal column ascending tract did not affect rhythm amplitude or phase. In contrast, bilateral transection of the main corticospinal tract significantly reduced the rhythm to 14.7(+/-6.6)%. These results indicate that the H-reflex circadian rhythm depends in part on descending influence from the brain and that this influence is conveyed by the main corticospinal tract.10acircadian rhythms10acorticospinal tract10adiurnal rhythm10aH-Reflex10arat10aspinal cord injury1 aChen, Xiang Yang1 aChen, Lu1 aWolpaw, Jonathan1 aJakeman, Lyn, B.  uhttp://www.ncbi.nlm.nih.gov/pubmed/1203185801479nas a2200157   4500008004100000022001400041245005300055210005100108260001200159300001400171490000600185520103600191653002501227100002101252856004801273       2002                        eng d  a1534-582300aMemory in neuroscience: rhetoric versus reality.0 aMemory in neuroscience rhetoric versus reality  c06/2002  a130–1630 v13 aThe central point of this article is that the concept of memory as information storage in the brain is inadequate for and irrelevant to understanding the nervous system. Beginning from the sensorimotor hypothesis that underlies neuroscience–that the entire function of the nervous system is to connect experience to appropriate behavior–the paper defines memories as sequences of events that connect remote experience to present behavior. Their essential components are (a) persistent events that bridge the time from remote experience to present behavior and (b) junctional events in which connections from remote experience and recent experience merge to produce behavior. The sequences comprising even the simplest memories are complex. This is both necessary–to preserve previously learned behaviors–and inevitable–due to secondary activity-driven plasticity. This complexity further highlights the inadequacy of the information storage concept and the importance of extreme simplicity in models used to study memory.10aPsychological Theory1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1771559002439nas a2200169   4500008004100000022001400041245007900055210006900134260001200203300001400215490000700229520191800236653002502154100002102179700002102200856004802221       2002                        eng d  a0022-307700aProbable corticospinal tract control of spinal cord plasticity in the rat.0 aProbable corticospinal tract control of spinal cord plasticity i  c02/2002  a645–6520 v873 aDescending activity from the brain shapes spinal cord reflex function throughout life, yet the mechanisms responsible for this spinal cord plasticity are poorly understood. Operant conditioning of the H-reflex, the electrical analogue of the spinal stretch reflex, is a simple model for investigating these mechanisms. An earlier study in the Sprague-Dawley rat showed that acquisition of an operantly conditioned decrease in the soleus H-reflex is not prevented by mid-thoracic transection of the ipsilateral lateral column (LC), which contains the rubrospinal, reticulospinal, and vestibulospinal tracts, and is prevented by transection of the dorsal column, which contains the main corticospinal tract (CST) and the dorsal column ascending tract (DA). The present study explored the effects of CST or DA transection on acquisition of an H-reflex decrease, and the effects of LC, CST, or DA transection on maintenance of an established decrease. CST transection prior to conditioning prevented acquisition of H-reflex decrease, while DA transection did not do so. CST transection after H-reflex decrease had been acquired led to gradual loss of the decrease over 10 days, and resulted in an H-reflex that was significantly larger than the original, naive H-reflex. In contrast, LC or DA transection after H-reflex decrease had been acquired did not affect maintenance of the decrease. These results, in combination with the earlier study, strongly imply that in the rat the corticospinal tract (CST) is essential for acquisition and maintenance of operantly conditioned decrease in the H-reflex and that other major spinal cord pathways are not essential. This previously unrecognized aspect of CST function gives insight into the processes underlying acquisition and maintenance of motor skills and could lead to novel methods for inducing, guiding, and assessing recovery of function after spinal cord injury.10aSpinal Cord Injuries1 aChen, Xiang Yang1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1182603302917nas a2200265   4500008004100000022001400041245009700055210006900152260001200221300001000233490000800243520213200251653002202383653001202405653002102417653001302438653001802451653002102469653000902490653004102499100001902540700002302559700002102582856004802603       2002                        eng d  a0165-027000aTemporal transformation of multiunit activity improves identification of single motor units.0 aTemporal transformation of multiunit activity improves identific  c02/2002  a87-980 v1143 a<p><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">This report describes a temporally based method for identifying repetitive firing of motor units. This&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">approach</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;is ideally suited to spike trains with negative serially correlated inter-spike intervals (ISIs). It can also be applied to spike trains in which ISIs exhibit little serial correlation if their coefficient of variation (COV) is sufficiently low. Using a novel application of the Hough transform, this method (i.e. the modified Hough transform (MHT)) maps motor unit action potential (MUAP) firing times into a feature space with ISI and offset (defined as the latency from an arbitrary starting time to the first MUAP in the train) as dimensions. Each MUAP firing time corresponds to a pattern in the feature space that represents all possible MUAP trains with a firing at that time. Trains with stable ISIs produce clusters in the feature space, whereas randomly firing trains do not. The MHT provides a direct estimate of mean firing rate and its variability for the entire data segment, even if several individual MUAPs are obscured by firings from other motor units. Addition of this method to a shape-based classification&nbsp;</span><span class="highlight" style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">approach</span><span style="font-family: arial, helvetica, clean, sans-serif; font-size: 13px; line-height: 17px;">&nbsp;markedly improved rejection of false positives using simulated data and identified spike trains in whole muscle electromyographic recordings from rats. The relative independence of the MHT from the need to correctly classify individual firings permits a global description of stable repetitive firing behavior that is complementary to shape-based approaches to MUAP classification.</span></p>10aAction Potentials10aAnimals10aElectromyography10aH-Reflex10aMotor Neurons10aMuscle, Skeletal10aRats10aSignal Processing, Computer-Assisted1 aSchalk, Gerwin1 aCarp, Jonathan, S.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1185004303278nas a2200229   4500008004100000022001400041245006900055210006700124260001200191300001400203490000700217520263700224653001302861653001702874653001302891653001102904653001902915653002302934100002102957700002202978856004803000       2001                        eng d  a0147-006X00aActivity-dependent spinal cord plasticity in health and disease.0 aActivitydependent spinal cord plasticity in health and disease  c03/2001  a807–8430 v243 aActivity-dependent plasticity occurs in the spinal cord throughout life. Driven by input from the periphery and the brain, this plasticity plays an important role in the acquisition and maintenance of motor skills and in the effects of spinal cord injury and other central nervous system disorders. The responses of the isolated spinal cord to sensory input display sensitization, long-term potentiation, and related phenomena that contribute to chronic pain syndromes; they can also be modified by both classical and operant conditioning protocols. In animals with transected spinal cords and in humans with spinal cord injuries, treadmill training gradually modifies the spinal cord so as to improve performance. These adaptations by the isolated spinal cord are specific to the training regimen and underlie new approaches to restoring function after spinal cord injury. Descending inputs from the brain that occur during normal development, as a result of supraspinal trauma, and during skill acquisition change the spinal cord. The early development of adult spinal cord reflex patterns is driven by descending activity; disorders that disrupt descending activity later in life gradually change spinal cord reflexes. Athletic training, such as that undertaken by ballet dancers, is associated with gradual alterations in spinal reflexes that appear to contribute to skill acquisition. Operant conditioning protocols in animals and humans can produce comparable reflex changes and are associated with functional and structural plasticity in the spinal cord, including changes in motoneuron firing threshold and axonal conduction velocity, and in synaptic terminals on motoneurons. The corticospinal tract has a key role in producing this plasticity. Behavioral changes produced by practice or injury reflect the combination of plasticity at multiple spinal cord and supraspinal sites. Plasticity at multiple sites is both necessary-to insure continued performance of previously acquired behaviors-and inevitable-due to the ubiquity of the capacity for activity-dependent plasticity in the central nervous system. Appropriate induction and guidance of activity-dependent plasticity in the spinal cord is an essential component of new therapeutic approaches aimed at maximizing function after spinal cord injury or restoring function to a newly regenerated spinal cord. Because plasticity in the spinal cord contributes to skill acquisition and because the spinal cord is relatively simple and accessible, this plasticity is a logical and practical starting point for studying the acquisition and maintenance of skilled behaviors.10abehavior10aconditioning10aLearning10aMemory10aRehabilitation10aspinal cord injury1 aWolpaw, Jonathan1 aTennissen, A., M.  uhttp://www.ncbi.nlm.nih.gov/pubmed/1152091901388nas a2200205   4500008004100000022001400041245005900055210005600114260001200170300001400182490000800196520081100204653002801015100001501043700001901058700001501077700002101092700002101113856004801134       2001                        eng d  a0033-290900aBrain-computer communication: unlocking the locked in.0 aBraincomputer communication unlocking the locked in  c05/2001  a358–3750 v1273 aWith the increasing efficiency of life-support systems and better intensive care, more patients survive severe injuries of the brain and spinal cord. Many of these patients experience locked-in syndrome: The active mind is locked in a paralyzed body. Consequently, communication is extremely restricted or impossible. A muscle-independent communication channel overcomes this problem and is realized through a brain-computer interface, a direct connection between brain and computer. The number of technically elaborated brain-computer interfaces is in contrast with the number of systems used in the daily life of locked-in patients. It is hypothesized that a profound knowledge and consideration of psychological principles are necessary to make brain-computer interfaces feasible for locked-in patients.10aUser-Computer Interface1 aKübler, A1 aKotchoubey, B.1 aKaiser, J.1 aWolpaw, Jonathan1 aBirbaumer, Niels  uhttp://www.ncbi.nlm.nih.gov/pubmed/1139330101678nas a2200277   4500008004100000022001400041245009700055210006900152260001200221300001000233490000800243520088300251653002201134653002101156653001301177653002501190653001601215653001501231653001801246653000801264100002301272700002101295700001501316700002101331856004801352       2001                        eng d  a0304-394000aEffects of chronic nerve cuff and intramuscular electrodes on rat triceps surae motor units.0 aEffects of chronic nerve cuff and intramuscular electrodes on ra  c10/2001  a1–40 v3123 aIn order to assess the long-term effects of implanted electrodes on motor unit properties, we studied triceps surae (TS) motor units in rats implanted for 3-10 months with a tibial nerve cuff electrode for H-reflex elicitation and intramuscular electrodes for recording TS electromyographic activity. Motor units with sag from implanted rats displayed greater tetanic force than those from unimplanted rats. Motor units without sag had shorter twitch contraction times. This disrupted the relationship between sag and contraction time that was always present in unimplanted rats. These differences were consistent with a small degree of muscle denervation and subsequent reinnervation. Further analyses ascribed this effect to the nerve cuff rather than to the intramuscular electrodes. Comparable changes in motor unit properties may occur in humans with implanted nerve cuffs.10achronic recording10acontraction time10aH-Reflex10aimplanted electrodes10amotor units10anerve cuff10areinnervation10asag1 aCarp, Jonathan, S.1 aChen, Xiang Yang1 aSheikh, H.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1157883102272nas a2200241   4500008004100000022001400041245007000055210006800125260001200193300001400205490000800219520158400227653001301811653002001824653002501844653001501869653001801884100002301902700002101925700001501946700002101961856004801982       2001                        eng d  a0014-481900aMotor unit properties after operant conditioning of rat H-reflex.0 aMotor unit properties after operant conditioning of rat Hreflex  c10/2001  a382–3860 v1403 aOperant conditioning of the H-reflex produces plasticity at several sites in the spinal cord, including the motoneuron. This study assessed whether this spinal cord plasticity is accompanied by changes in motor unit contractile properties. Thirty-one adult male Sprague-Dawley rats implanted for chronic recording of triceps surae electromyographic activity and H-reflex elicitation were exposed for at least 40 days to HRup or HRdown training, in which reward occurred when the H-reflex was greater than (12 HRup rats) or less than (12 HRdown rats) a criterion value, or continued under the control mode in which the H-reflex was simply measured (7 HRcon rats). At the end of H-reflex data collection, rats were anesthetized and the contractile properties of 797 single triceps surae motor units activated by intraaxonal (or intramyelin) current injection were determined. Motor units were classified as S, FR, Fint, or FF on the basis of sag and fatigue properties. Maximum tetanic force and twitch contraction time were also measured. HRdown rats exhibited a significant increase in the fatigue index of fast-twitch motor units. This resulted in a significant decrease in the percentage of Fint motor units and a significant increase in that of FR motor units. HRup conditioning had no effect on fatigue index. Neither HRup nor HRdown conditioning affected maximum tetanic force or twitch contraction time. These data are consistent with the hypothesis that conditioning mode-specific change in motoneuron firing patterns causes activity-dependent change in muscle properties.10aH-Reflex10amotor unit type10aoperant conditioning10aplasticity10atriceps surae1 aCarp, Jonathan, S.1 aChen, Xiang Yang1 aSheikh, H.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1168131402242nas a2200241   4500008004100000022001400041245008800055210006900143260001200212300001400224490000800238520154300246653002401789653001301813653001501826653001501841653001601856100002301872700002101895700001501916700002101931856004801952       2001                        eng d  a0014-481900aOperant conditioning of rat H-reflex affects motoneuron axonal conduction velocity.0 aOperant conditioning of rat Hreflex affects motoneuron axonal co  c01/2001  a269–2730 v1363 aThis study assessed the effects of operant conditioning of the H-reflex on motoneuron axonal conduction velocity in the rat. After measurement of the control H-reflex size, rats were either exposed for at least 40 days to the HRup or HRdown conditioning mode, in which reward occurred only if the soleus H-reflex was greater than (HRup mode) or less than (HRdown mode) a criterion or continued under the control condition (HRcon mode) in which the H-reflex was simply measured. We then measured axonal conduction velocity of triceps surae motor units of HRup, HRdown, and HRcon rats by stimulating the axon in the ventral root and recording from the tibial nerve. Conduction velocity was 8% less in successful HRdown rats than in HRcon rats (P=0.02). Conduction velocity in HRup rats and unsuccessful HRdown rats was not significantly different from that in HRcon rats. Since recording bypassed the intra-spinal portion of the motoneuron, the change was clearly in the axon. This decrease was similar to the 6% decrease previously found in successful HRdown monkeys. Unsuccessful HRdown rats and monkeys did not show this decrease. This result suggests that the mechanism of HRdown conditioning is similar in rats and monkeys and provides further support for the hypothesis that HRdown conditioning decreases motoneuron excitability by producing a positive shift in firing threshold. While traditional theories of learning emphasize synaptic plasticity, neuronal plasticity may also contribute to operantly conditioned behavioral changes.10aconduction velocity10aH-Reflex10amotoneuron10aplasticity10aSpinal Cord1 aCarp, Jonathan, S.1 aChen, Xiang Yang1 aSheikh, H.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1120629002143nas a2200217   4500008004100000022001400041245008000055210006900135260001200204300001400216490000800230520152500238653001701763653001301780653001101793653001501804653001601819100002101835700002101856856004801877       2001                        eng d  a0014-481900aOperant conditioning of rat H-reflex: effects on mean latency and duration.0 aOperant conditioning of rat Hreflex effects on mean latency and   c01/2001  a274–2790 v1363 aWe are currently studying the mechanisms of operantly conditioned changes in the H-reflex in the rat. Primate data suggest that H-reflex decrease is due to a positive shift in motoneuron firing threshold and a small decrease in the monosynaptic excitatory postsynaptic potential (EPSP), and that increase might be due to change in group-I oligosynaptic (especially disynaptic) input. To further evaluate the possibility of conditioned change in oligosynaptic input, we compared the mean latency (i.e., the average latency of the entire H-reflex) and the duration of control (i.e., pre-conditioning) H-reflexes with those of H-reflexes after up-conditioning or down-conditioning. Up-conditioning was associated with small, statistically significant increases in H-reflex mean latency [+0.11+/-0.05 (+/-SE) ms] and duration (+0.32+/-0.16 ms). The mean latency of the H-reflex increase (i.e., the part added to the H-reflex by up-conditioning) was 0.28+/-0.14 (+/-SE) ms greater than that of the control H-reflex. Down-conditioning had no significant effect on mean latency or duration. While these results indicate that operant conditioning does not greatly change H-reflex mean latency or duration, the effects detected with up-conditioning are consistent with the hypothesis that decreased inhibition, or increased excitation, by homonymous and heteronymous group-I oligosynaptic input contributes to the H-reflex increase produced by up-conditioning. Several other mechanisms might also account for these small effects.10aconditioning10aH-Reflex10aMemory10aplasticity10aSpinal Cord1 aWolpaw, Jonathan1 aChen, Xiang Yang  uhttp://www.ncbi.nlm.nih.gov/pubmed/1120629102808nas a2200277   4500008004100000022001400041245011500055210006900170260001200239300001400251490000700265520196900272653002402241653001802265653003402283653001902317653000802336653002002344653002302364100002102387700002202408700001302430700001802443700002102461856004802482       2001                        eng d  a0897-715100aShort-Term and medium-term effects of spinal cord tract transections on soleus H-reflex in freely moving rats.0 aShortTerm and mediumterm effects of spinal cord tract transectio  c03/2001  a313–3270 v183 aSpinal cord function is normally influenced by descending activity from supraspinal structures. When injury removes or distorts this influence, function changes and spasticity and other disabling problems eventually appear. Understanding how descending activity affects spinal cord function could lead to new means for inducing, guiding, and assessing recovery after injury. In this study, we investigated the short-term and medium-term effects of spinal cord bilateral dorsal column (DC), unilateral (ipsilateral) lateral column (LC), bilateral dorsal column ascending tract (DA), or bilateral dorsal column corticospinal tract (CST) transection at vertebral level T8-T9 on the soleus H-reflex in freely moving rats. Data were collected continuously for 10-20 days before and for 20-155 days after bilateral DC (13 rats), DA (10 rats), CST (eight rats), or ipsilateral LC (seven rats) transection. Histological examination showed that transections were 98(+/- 3 SD)% complete for DC rats, 80(+/- 20)% complete for LC rats, 91(+/- 13 SD)% complete for DA rats, and 95(+/-13)% complete for CST rats. LC, CST, and DA transections produced an immediate (i.e., first-day) increase in H-reflex amplitude. LC transection also produced a small decrease in background activity in the first few posttransection days. Other than this small decrease, none of the transections produced evidence for the phenomenon of spinal shock. For all transections, all measures returned to or neared pretransection values within 2 weeks. DA and LC transections were associated with modest increase in H-reflex amplitude 1-3 months after transection. These medium-term effects must be taken into account when assessing transection effects on operant conditioning of the H-reflex. At the same time, the results are consistent with other evidence that, while H-reflex rate dependence and H-reflex operant conditioning are sensitive measures of spinal cord injury, the H-reflex itself is not.10acorticospinal tract10adorsal column10adorsal column ascending tract10alateral column10arat10asoleus activity10aspinal cord injury1 aChen, Xiang Yang1 aFeng-Chen, K., C.1 aChen, Lu1 aStark, D., M.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1128455100491nas a2200157   4500008004100000022001400041245006900055210006700124260001200191300001600203490000700219653002100226100002100247700001700268856004800285       2001                        eng d  a0028-387800aTaking sides: corticospinal tract plasticity during development.0 aTaking sides corticospinal tract plasticity during development  c11/2001  a1530–15310 v5710aPyramidal Tracts1 aWolpaw, Jonathan1 aKaas, J., H.  uhttp://www.ncbi.nlm.nih.gov/pubmed/1170608401999nas a2200253   4500008004100000022001400041245005300055210005100108260001200159300001200171490000800183520136000191653001701551653001301568653001101581653001501592653000801607653001101615653001601626100002101642700001301663700002101676856004801697       2001                        eng d  a0304-394000aTime course of H-reflex conditioning in the rat.0 aTime course of Hreflex conditioning in the rat  c04/2001  a85–880 v3023 aThis study sought to define the course of operantly conditioned change in the rat soleus H-reflex and to determine whether, like H-reflex conditioning and spinal stretch reflex conditioning in the monkey, it develops in distinct phases. Data from 33 rats in which the right soleus H-reflex was trained up (i.e. HRup mode) and 38 in which it was trained down (i.e. HRdown mode) were averaged to define the courses of H-reflex increase and decrease. In HRup rats, the H-reflex showed a large phase I increase within the first 2 days followed by gradual phase II increase that continued for weeks. In HRdown rats, the H-reflex appeared to show a small phase I decrease and then showed a gradual phase II decrease over weeks. In combination with other recent work, the data suggest that H-reflex conditioning begins with a rapid mode-appropriate alteration in corticospinal tract influence over the spinal arc of the H-reflex, which causes phase I change, and that the continuation of this altered influence induces gradual spinal cord plasticity that is responsible for phase II change. The results further establish the similarity of H-reflex conditioning in primates and rats. Thus, they encourage efforts to produce a single coherent model of the phenomenon based on data from the two species and indicate the potential clinical relevance of the rat data.10aconditioning10aLearning10aMemory10aplasticity10arat10aReflex10aSpinal Cord1 aChen, Xiang Yang1 aChen, Lu1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1129039301157nas a2200181   4500008004100000022001400041245006300055210006100118260001200179300001400191490000600205520061700211653002800828100002100856700002600877700002400903856004800927       2000                        eng d  a1063-652800aBrain-computer interface research at the Wadsworth Center.0 aBraincomputer interface research at the Wadsworth Center  c06/2000  a222–2260 v83 aStudies at the Wadsworth Center over the past 14 years have shown that people with or without motor disabilities can learn to control the amplitude of mu or beta rhythms in electroencephalographic (EEG) activity recorded from the scalp over sensorimotor cortex and can use that control to move a cursor on a computer screen in one or two dimensions. This EEG-based brain-computer interface (BCI) could provide a new augmentative communication technology for those who are totally paralyzed or have other severe motor impairments. Present research focuses on improving the speed and accuracy of BCI communication.10aUser-Computer Interface1 aWolpaw, Jonathan1 aMcFarland, Dennis, J.1 aVaughan, Theresa, M  uhttp://www.ncbi.nlm.nih.gov/pubmed/1089619402866nas a2200289   4500008004100000022001400041245008600055210006900141260001200210300001400222490000600236520197100242653003102213653003502244653003302279100002102312700002102333700002202354700002602376700002002402700001902422700002102441700002102462700002102483700002402504856004802528       2000                        eng d  a1063-652800aBrain-computer interface technology: a review of the first international meeting.0 aBraincomputer interface technology a review of the first interna  c06/2000  a164–1730 v83 aOver the past decade, many laboratories have begun to explore brain-computer interface (BCI) technology as a radically new communication option for those with neuromuscular impairments that prevent them from using conventional augmentative communication methods. BCI's provide these users with communication channels that do not depend on peripheral nerves and muscles. This article summarizes the first international meeting devoted to BCI research and development. Current BCI's use electroencephalographic (EEG) activity recorded at the scalp or single-unit activity recorded from within cortex to control cursor movement, select letters or icons, or operate a neuroprosthesis. The central element in each BCI is a translation algorithm that converts electrophysiological input from the user into output that controls external devices. BCI operation depends on effective interaction between two adaptive controllers, the user who encodes his or her commands in the electrophysiological input provided to the BCI, and the BCI which recognizes the commands contained in the input and expresses them in device control. Current BCI's have maximum information transfer rates of 5-25 b/min. Achievement of greater speed and accuracy depends on improvements in signal processing, translation algorithms, and user training. These improvements depend on increased interdisciplinary cooperation between neuroscientists, engineers, computer programmers, psychologists, and rehabilitation specialists, and on adoption and widespread application of objective methods for evaluating alternative methods. The practical use of BCI technology depends on the development of appropriate applications, identification of appropriate user groups, and careful attention to the needs and desires of individual users. BCI research and development will also benefit from greater emphasis on peer-reviewed publications, and from adoption of standard venues for presentations and discussion.10aaugmentative communication10aBrain-computer interface (BCI)10aelectroencephalography (EEG)1 aWolpaw, Jonathan1 aBirbaumer, Niels1 aHeetderks, W., J.1 aMcFarland, Dennis, J.1 aPeckham, P., H.1 aSchalk, Gerwin1 aDonchin, Emanuel1 aQuatrano, L., A.1 aRobinson, C., J.1 aVaughan, Theresa, M  uhttp://www.ncbi.nlm.nih.gov/pubmed/1089617803091nas a2200373   4500008004100000022001400041245008600055210006900141260001200210300001100222490000600233520197800239653001502217653002002232653003602252653002102288653002702309653002202336653001102358653002702369653004102396653002802437100002102465700002102486700001902507700002602526700001702552700001902569700002102588700001802609700001802627700002402645856004802669       2000                        eng d  a1063-652800aBrain-computer interface technology: a review of the first international meeting.0 aBraincomputer interface technology a review of the first interna  c06/2000  a164-730 v83 a<p>Over the past decade, many laboratories have begun to explore brain-computer interface (BCI) technology as a radically new communication option for those with neuromuscular impairments that prevent them from using conventional augmentative communication methods. BCI's provide these users with communication channels that do not depend on peripheral nerves and muscles. This article summarizes the first international meeting devoted to BCI research and development. Current BCI's use electroencephalographic (EEG) activity recorded at the scalp or single-unit activity recorded from within cortex to control cursor movement, select letters or icons, or operate a neuroprosthesis. The central element in each BCI is a translation algorithm that converts electrophysiological input from the user into output that controls external devices. BCI operation depends on effective interaction between two adaptive controllers, the user who encodes his or her commands in the electrophysiological input provided to the BCI, and the BCI which recognizes the commands contained in the input and expresses them in device control. Current BCI's have maximum information transfer rates of 5-25 b/min. Achievement of greater speed and accuracy depends on improvements in signal processing, translation algorithms, and user training. These improvements depend on increased interdisciplinary cooperation between neuroscientists, engineers, computer programmers, psychologists, and rehabilitation specialists, and on adoption and widespread application of objective methods for evaluating alternative methods. The practical use of BCI technology depends on the development of appropriate applications, identification of appropriate user groups, and careful attention to the needs and desires of individual users. BCI research and development will also benefit from greater emphasis on peer-reviewed publications, and from adoption of standard venues for presentations and discussion.</p>10aAlgorithms10aCerebral Cortex10aCommunication Aids for Disabled10aDisabled Persons10aElectroencephalography10aEvoked Potentials10aHumans10aNeuromuscular Diseases10aSignal Processing, Computer-Assisted10aUser-Computer Interface1 aWolpaw, Jonathan1 aBirbaumer, Niels1 aHeetderks, W J1 aMcFarland, Dennis, J.1 aPeckham, P H1 aSchalk, Gerwin1 aDonchin, Emanuel1 aQuatrano, L A1 aRobinson, C J1 aVaughan, Theresa, M  uhttp://www.ncbi.nlm.nih.gov/pubmed/1089617801315nas a2200289   4500008004100000022001400041245006100055210005800116260001200174300001600186490000800202520045900210653003100669653002900700653002700729653002000756653002900776653002800805653001400833653001900847653002400866100001900890700002100909700002600930700002100956856004800977       2000                        eng d  a1388-245700aEEG-based communication: presence of an error potential.0 aEEGbased communication presence of an error potential  c12/2000  a2138–21440 v1113 aEEG-based communication could be a valuable new augmentative communication technology for those with severe motor disabilities. Like all communication methods, it faces the problem of errors in transmission. In the Wadsworth EEG-based brain-computer interface (BCI) system, subjects learn to use mu or beta rhythm amplitude to move a cursor to targets on a computer screen. While cursor movement is highly accurate in trained subjects, it is not perfect.10aaugmentative communication10abrain-computer interface10aElectroencephalography10aerror potential10aerror related negativity10aevent related potential10amu rhythm10aRehabilitation10asensorimotor cortex1 aSchalk, Gerwin1 aWolpaw, Jonathan1 aMcFarland, Dennis, J.1 aPfurtscheller, G  uhttp://www.ncbi.nlm.nih.gov/pubmed/1109076300530nas a2200169   4500008004100000022001400041245009500055210006900150260001200219300001000231490000700241653001100248653001200259100002000271700002100291856004800312       2000                        eng d  a0028-387800aEmerging concepts in the pathophysiology of recovery from neonatal brachial plexus injury.0 aEmerging concepts in the pathophysiology of recovery from neonat  c07/2000  a5–60 v5510aInfant10aNewborn1 aNoetzel, M., J.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1089189502265nas a2200241   4500008004100000022001400041245007900055210006900134260001200203300001400215490000700229520157600236653001601812653000801828653001201836653001401848653002401862100002601886700001801912700002401930700002101954856004801975       2000                        eng d  a0896-026700aMu and beta rhythm topographies during motor imagery and actual movements.0 aMu and beta rhythm topographies during motor imagery and actual   c03/2000  a177–1860 v123 aPeople can learn to control the 8-12 Hz mu rhythm and/or the 18-25 Hz beta rhythm in the EEG recorded over sensorimotor cortex and use it to control a cursor on a video screen. Subjects often report using motor imagery to control cursor movement, particularly early in training. We compared in untrained subjects the EEG topographies associated with actual hand movement to those associated with imagined hand movement. Sixty-four EEG channels were recorded while each of 33 adults moved left- or right-hand or imagined doing so. Frequency-specific differences between movement or imagery and rest, and between right- and left-hand movement or imagery, were evaluated by scalp topographies of voltage and r spectra, and principal component analysis. Both movement and imagery were associated with mu and beta rhythm desynchronization. The mu topographies showed bilateral foci of desynchronization over sensorimotor cortices, while the beta topographies showed peak desynchronization over the vertex. Both mu and beta rhythm left/right differences showed bilateral central foci that were stronger on the right side. The independence of mu and beta rhythms was demonstrated by differences for movement and imagery for the subjects as a group and by principal components analysis. The results indicated that the effects of imagery were not simply an attenuated version of the effects of movement. They supply evidence that motor imagery could play an important role in EEG-based communication, and suggest that mu and beta rhythms might provide independent control signals.10abeta rhythm10aEEG10aimagery10amu rhythm10asensorimotor cortex1 aMcFarland, Dennis, J.1 aMiner, L., A.1 aVaughan, Theresa, M1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1079168101892nas a2200229   4500008004100000022001400041245007400055210006900129260001200198300001400210490000800224520124700232653001801479653001101497653001401508100001801522700001501540700001701555700002101572700002101593856004801614       2000                        eng d  a0014-481900aWhat do reflex and voluntary mean? Modern views on an ancient debate.0 aWhat do reflex and voluntary mean Modern views on an ancient deb  c02/2000  a417–4320 v1303 aAre the words reflex and voluntary useful scientific concepts, or are they prescientific terms that should be discarded? Physiologists use these words routinely in their publications, in laboratory experiments and, indeed, like most lay people, in their daily lives. The tacit assumption is that we all know, more or less, what they mean. However, the issue has a rich history of philosophical and scientific debate; and, as this article demonstrates, present-day researchers still cannot reach a consensus on the meaning of the words and on whether it is possible to draw a scientific distinction between them. The five authors present five quite different analyses. In broad terms, they split into two camps: those who equate voluntary behaviours with consciousness and suppressibility and those who view all behaviours as sensorimotor interactions, the complexity of which determines whether they are reflexive or voluntary. According to the first view, most movements of daily life are neither purely reflex nor purely voluntary. They fall into the middle ground of automatic motor programs. According to the second view, as neuroscience advances the class of reflex behaviours will grow and the class of voluntary behaviours will shrink.10aConsciousness10aReflex10avoluntary1 aProchazka, A.1 aClarac, F.1 aLoeb, G., E.1 aRothwell, J., C.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1071778502520nas a2200253   4500008004100000022001400041245007700055210007100132260001200203300001400215490000700229520179900236653001302035653002502048653001502073653000802088653001802096653002302114100002102137700002102158700002002179700001902199856004802218       1999                        eng d  a0897-715100aOperant conditioning of H-reflex increase in spinal cord–injured rats.0 aOperant conditioning of Hreflex increase in spinal cord–injured   c02/1999  a175–1860 v163 aOperant conditioning of the spinal stretch reflex or its electrical analog, the H-reflex, is a new model for exploring the mechanisms of long-term supraspinal control over spinal cord function. Primates and rats can gradually increase (HRup conditioning mode) or decrease (HRdown conditioning mode) the H-reflex when reward is based on H-reflex amplitude. An earlier study indicated that HRdown conditioning of the soleus H-reflex in rats is impaired following contusion injury to thoracic spinal cord. The extent of impairment was correlated with the percent of white matter lost at the injury site. The present study investigated the effects of spinal cord injury on HRup conditioning. Soleus H-reflexes were elicited and recorded with chronically implanted electrodes from 14 rats that had been subjected to calibrated contusion injuries to the spinal cord at T8. At the lesion epicenter, 12-39% of the white matter remained. After control-mode data were collected, each rat was exposed to the HRup conditioning mode for 50 days. Final H-reflex amplitudes after HRup conditioning averaged 112% (+/-22% SD) of control. This value was significantly smaller than that for 13 normal rats exposed to HRup conditioning, in which final amplitude averaged 153% (+/-51%) SD of control. As previously reported for HRdown conditioning after spinal cord injury, success was inversely correlated with the severity of the injury as assessed by white matter preservation and by time to return of bladder function. HRup and HRdown conditioning are similarly sensitive to injury. These results further demonstrate that H-reflex conditioning is a sensitive measure of the long-term effects of injury on supraspinal control over spinal cord functions and could prove a valuable measure of therapeutic efficacy.10aH-Reflex10aoperant conditioning10aplasticity10arat10asoleus muscle10aspinal cord injury1 aChen, Xiang Yang1 aWolpaw, Jonathan1 aJakeman, L., B.1 aStokes, B., T.  uhttp://www.ncbi.nlm.nih.gov/pubmed/1009896203180nas a2200193   4500008004100000022001400041245007800055210006900133260001200202300001600214490000700230520258700237653002402824100002302848700002502871700002102896700002102917856004802938       1999                        eng d  a0022-307700aSag during unfused tetanic contractions in rat triceps surae motor units.0 aSag during unfused tetanic contractions in rat triceps surae mot  c06/1999  a2647–26610 v813 aContractile properties and conduction velocity were studied in 202 single motor units of intact rat triceps surae muscles activated by intra-axonal (or intra-myelin) current injection in L5 or L6 ventral root to assess the factors that determine the expression of sag (i.e., decline in force after initial increase during unfused tetanic stimulation). Sag was consistently detected in motor units with unpotentiated twitch contraction times <20 ms. However, the range of frequencies at which sag was expressed varied among motor units such that there was no single interstimulus interval (ISI), with or without adjusting for twitch contraction time, at which sag could be detected reliably. Further analysis indicated that using the absence of sag as a criterion for identifying slow-twitch motor units requires testing with tetani at several different ISIs. In motor units with sag, the shape of the force profile varied with tetanic frequency and contractile properties. Simple sag force profiles (single maximum reached late in the tetanus followed by monotonic decay) tended to occur at shorter ISIs and were observed more frequently in fatigue-resistant motor units with long half-relaxation times and small twitch amplitudes. Complex sag profiles reached an initial maximum early in the tetanus, tended to occur at longer ISIs, and were more common in fatigue-sensitive motor units with long half-relaxation times and large twitch amplitudes. The differences in frequency dependence and force maximum location suggested that these phenomena represented discrete entities. Successive stimuli elicited near-linear increments in force during tetani in motor units that never exhibited sag. In motor units with at least one tetanus displaying sag, tetanic stimulation elicited large initial force increments followed by rapidly decreasing force increments. That the latter force envelope pattern occurred in these units even in tetani without sag suggested that the factors responsible for sag were expressed in the absence of overt sag. The time-to-peak force (TTP) of the individual contractions during a tetanus decreased in tetani with sag. Differences in the pattern of TTP change during a tetanus were consistent with the differences in force maximum location between tetani exhibiting simple and complex sag. Tetani from motor units that never exhibited sag did not display a net decrease in TTP during successive contractions. These data were consistent with the initial force decrement of sag resulting from a transient reduction in the duration of the contractile state.10aRegression Analysis1 aCarp, Jonathan, S.1 aHerchenroder, P., A.1 aChen, Xiang Yang1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/1036838502346nas a2200181   4500008004100000022001400041245008500055210006900140260001200209300001600221490000700237520178000244653002802024100001802052700002602070700002102096856004702117       1998                        eng d  a0003-999300aAnswering questions with an electroencephalogram-based brain-computer interface.0 aAnswering questions with an electroencephalogrambased braincompu  c09/1998  a1029–10330 v793 aOBJECTIVE:
To demonstrate that humans can learn to control selected electroencephalographic components and use that control to answer simple questions.
METHODS:
Four adults (one with amyotrophic lateral sclerosis) learned to use electroencephalogram (EEG) mu rhythm (8 to 12Hz) or beta rhythm (18 to 25Hz) activity over sensorimotor cortex to control vertical cursor movement to targets at the top or bottom edge of a video screen. In subsequent sessions, the targets were replaced with the words YES and NO, and individuals used the cursor to answer spoken YES/NO questions from single- or multiple-topic question sets. They confirmed their answers through the response verification (RV) procedure, in which the word positions were switched and the question was answered again.
RESULTS:
For 5 consecutive sessions after initial question training, individuals were asked an average of 4.0 to 4.6 questions per minute; 64% to 87% of their answers were confirmed by the RV procedure and 93% to 99% of these answers were correct. Performances for single- and multiple-topic question sets did not differ significantly.
CONCLUSIONS:
The results indicate that (1) EEG-based cursor control can be used to answer simple questions with a high degree of accuracy, (2) attention to auditory queries and formulation of answers does not interfere with EEG-based cursor control, (3) question complexity (at least as represented by single versus multiple-topic question sets) does not noticeably affect performance, and (4) the RV procedure improves accuracy as expected. Several options for increasing the speed of communication appear promising. An EEG-based brain-computer interface could provide a new communication and control modality for people with severe motor disabilities.10aUser-Computer Interface1 aMiner, L., A.1 aMcFarland, Dennis, J.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/974967802088nas a2200265   4500008004100000022001400041245006600055210006300121260001200184300001400196490000800210520131500218653003101533653001701564653002701581653002101608653001401629653001901643653002401662100002401686700001801710700002601728700002101754856004701775       1998                        eng d  a0013-469400aEEG-based communication: analysis of concurrent EMG activity.0 aEEGbased communication analysis of concurrent EMG activity  c12/1998  a428–4330 v1073 aOBJECTIVE:
Recent studies indicate that people can learn to control the amplitude of mu or beta rhythms in the EEG recorded from the scalp over sensorimotor cortex and can use that control to move a cursor to targets on the computer screen. While subjects do not move during performance, it is possible that inapparent or unconscious muscle contractions contribute to the changes in the mu and beta rhythm activity responsible for cursor movement. We evaluated this possibility.
METHODS:
EMG was recorded from 10 distal limb muscle groups while five trained subjects used mu or beta rhythms to move a cursor to targets at the bottom or top edge of a computer screen.
RESULTS:
EMG activity was very low during performance, averaging 4.0+/-4.4% (SD) of maximum voluntary contraction. Most important, the correlation, measured as r2, between target position and EMG activity averaged only 0.01+/-0.02, much lower than the correlation between target position and the EEG activity that controlled cursor movement, which averaged 0.39+/-0.18.
CONCLUSIONS:
These results strongly support the conclusion that EEG-based cursor control does no depend on concurrent muscle activity. EEG-based communication and control might provide a new augmentative communication option for those with severe motor disabilities.10aaugmentative communication10aconditioning10aElectroencephalography10aElectromyography10amu rhythm10aRehabilitation10asensorimotor cortex1 aVaughan, Theresa, M1 aMiner, L., A.1 aMcFarland, Dennis, J.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/992208901613nas a2200181   4500008004100000022001400041245007000055210006600125260001200191300001100203490000600214520106600220653003201286100002601318700001901344700002101363856004701384       1998                        eng d  a1063-652800aEEG-based communication and control: short-term role of feedback.0 aEEGbased communication and control shortterm role of feedback  c03/1998  a7–110 v63 aWhen people learn to control the amplitudes of certain electroencephalogram (EEG) components (e.g., the 8-12 Hz mu-rhythm over sensorimotor cortex) and use them to move a cursor to a target on a video screen, feedback about performance is normally provided by cursor movement and by trial outcome (i.e., success or failure). We assessed the short-term effects of this feedback on EEG control. After subjects received initial training with feedback present, feedback was removed intermittently for periods of several minutes. Subjects still displayed EEG control when feedback was removed. Removal of cursor movement alone appeared to have effects comparable to removal of both cursor movement and trial outcome. These results show that, in the short-term at least, mu-rhythm control is not dependent on the sensory input provided by cursor movement. They also suggest that feedback can have inhibitory as well as facilitory effects on EEG control, and that these effects vary across subjects. This finding has implications for the design of training procedures.10aSensitivity and Specificity1 aMcFarland, Dennis, J.1 aMcCane, L., M.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/953551801936nas a2200205   4500008004100000022001400041245007300055210006900128260001200197300001400209490000600223520132600229653002201555653002201577100002101599700001601620700002601636700002101662856004701683       1998                        eng d  a1063-652800aEEG-based communication: improved accuracy by response verification.0 aEEGbased communication improved accuracy by response verificatio  c09/1998  a326–3330 v63 aHumans can learn to control the amplitude of electroencephalographic (EEG) activity in specific frequency bands over sensorimotor cortex and use it to move a cursor to a target on a computer screen. EEG-based communication could provide a new augmentative communication channel for individuals with motor disabilities. In the present system, each dimension of cursor movement is controlled by a linear equation. While the intercept in the equation is continually updated, it does not perfectly eliminate the impact of spontaneous variations in EEG amplitude. This imperfection reduces the accuracy of cursor movement. We evaluated a response verification (RV) procedure in which each outcome is determined by two opposite trials (e.g., one top-target trial and one bottom-target trial). Success, or failure, on both is required for a definitive outcome. The RV procedure reduces errors due to imperfection in intercept selection. Accuracy for opposite-trial pairs exceeds that predicted from the accuracies of individual trials, and greatly exceeds that for same-trial pairs. The RV procedure should be particularly valuable when the first trial has >2 possible targets, because the second trial need only confirm or deny the outcome of the first, and it should be applicable to nonlinear as well as to linear algorithms.10aComputer-Assisted10aSignal Processing1 aWolpaw, Jonathan1 aRamoser, H.1 aMcFarland, Dennis, J.1 aPfurtscheller, G  uhttp://www.ncbi.nlm.nih.gov/pubmed/974991001573nas a2200229   4500008004100000022001400041245004600055210004100101260001200142300001400154490000700168520098800175653001301163653001301176653001101189653002501200653001501225653001601240653001901256100002101275856004701296       1997                        eng d  a0166-223600aThe complex structure of a simple memory.0 acomplex structure of a simple memory  c12/1997  a588–5940 v203 aOperant conditioning of the vertebrate H-reflex, which appears to be closely related to learning that occurs in real life, is accompanied by plasticity at multiple sites. Change occurs in the firing threshold and conduction velocity of the motoneuron, in several different synaptic terminal populations on the motoneuron, and probably in interneurons as well. Change also occurs contralaterally. The corticospinal tract probably has an essential role in producing this plasticity. While certain of these changes, such as that in the firing threshold, are likely to contribute to the rewarded behavior (primary plasticity), others might preserve previously learned behaviors (compensatory plasticity), or are simply activity-driven products of change elsewhere (reactive plasticity). As these data and those from other simple vertebrate and invertebrate models indicate, a complex pattern of plasticity appears to be the necessary and inevitable outcome of even the simplest learning.10aH-Reflex10aLearning10aMemory10aoperant conditioning10aplasticity10aSpinal Cord10astretch reflex1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/941667303032nas a2200169   4500008004100000022001400041245010100055210006900156260001200225300001600237490000700253520249700260653001602757100002102773700002102794856004702815       1997                        eng d  a0022-307700aDorsal column but not lateral column transection prevents down-conditioning of H reflex in rats.0 aDorsal column but not lateral column transection prevents downco  c09/1997  a1730–17340 v783 aOperant conditioning of the H reflex, the electrical analogue of the spinal stretch reflex, in freely moving rats is a relatively simple model for studying long-term supraspinal control over spinal cord function. Motivated by food reward, rats can gradually increase or decrease the soleus H reflex. This study is the first effort to determine which spinal cord pathways convey the descending influence from supraspinal structures that changes the H reflex. In anesthetized Sprague-Dawley rats, the entire dorsal column (DC), which includes the main corticospinal tract, or the right lateral column (LC) was transected by electrocautery. Animals recovered quickly and the minimal transient effects of transection on the right soleus H reflex disappeared within 16 days. Beginning at least 18 days after transection, 12 rats were exposed to the HRdown-conditioning mode, in which reward was given when the H reflex of the right soleus muscle was below a criterion value. In seven LC rats exposed to the HRdown mode, the H reflex fell to 71 +/- 8% (mean +/- SE) of its initial value. In six of the seven, conditioning was successful (i.e., decrease to < or = 80%). These results were comparable with those previously obtained from normal rats. In contrast, in five DC rats exposed to the HRdown mode, the H reflex at the end of exposure was 106 +/- 12% of its initial value. In none of these rats was HRdown-conditioning successful. DC rats differed significantly from normal and LC rats in both final H reflex values and number successful. In five DC and three LC rats that continued under control conditions over 30-78 days, the H reflex at the end of the period was 98 +/- 4% and 100 +/- 8%, respectively, of its initial value, indicating that DC or LC transection itself did not lead to gradual increase or decrease in the H reflex. The results indicate that the DC, containing the main corticospinal tract, is essential for HRdown-conditioning, whereas the ipsilateral LC, containing the main rubrospinal, vestibulospinal, and reticulospinal tracts, is not essential. Combined with the known muscular specificity of conditioning, these results suggest that the main corticospinal tract is essential for HRdown-conditioning. The DC ascending tract might also be necessary. The respective roles of the DC descending and ascending tracts, and transection effects on HRup-conditioning and on the maintenance of both HRup- and HRdown-conditioning after they have occurred, remain to be defined.10aSpinal Cord1 aChen, Xiang Yang1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/931045802392nas a2200181   4500008004100000022001400041245008200055210006900137260001200206300001400218490000700232520184100239653002502080100001602105700002102121700002102142856004702163       1997                        eng d  a0013-558500aEEG-based communication: evaluation of alternative signal prediction methods.0 aEEGbased communication evaluation of alternative signal predicti  c09/1997  a226–2330 v423 aIndividuals can learn to control the amplitude of EEG activity in specific frequency bands over sensorimotor cortex and use it to move a cursor to a target on a computer screen. For one-dimensional (i.e., vertical) cursor movement, a linear equation translates the EEG activity into cursor movement. To translate an individual's EEG control into cursor control as effectively as possible, the intercept in this equation, which determines whether upward or downward movement occurs, should be set so that top and bottom targets are equally accessible. The present study compares alternative methods for using an individual's previous performance to select the intercept for subsequent trials. In offline analyses, five different intercept selection methods were applied to EEG data collected while trained subjects were moving the cursor to targets at the top or bottom edge of the screen. In the first two methods-moving average, and weighted sum-a single intercept was selected for the entire 1-2 sec period of each trial. In the other three methods-blocked moving average, blocked weighted sum, and blocked recursive sum (a variation of the weighted sum)-an intercept was selected for each 200-ms segment of the trial. The results from these methods were compared in regard to their balance between upward and downward movements and their consistency of performance across trials. For all subjects combined, the five methods performed similarly. However, performance across subjects was more consistent for the moving average, blocked moving average, and blocked recursive sum methods than for the weighted sum and blocked weighted sum methods. Due to its consistent performance and its computational simplicity, the moving average method, using the five most recent pairs of top and bottom trials, appears to be the method of choice.10aSomatosensory Cortex1 aRamoser, H.1 aWolpaw, Jonathan1 aPfurtscheller, G  uhttp://www.ncbi.nlm.nih.gov/pubmed/934288702193nas a2200265   4500008004100000022001400041245005800055210005600113260001200169300001400181490000800195520144100203653002801644653002701672653001401699653002501713653001501738653001901753653002401772100002601796700001901822700001801841700002101859856004701880       1997                        eng d  a0013-469400aSpatial filter selection for EEG-based communication.0 aSpatial filter selection for EEGbased communication  c09/1997  a386–3940 v1033 aIndividuals can learn to control the amplitude of mu-rhythm activity in the EEG recorded over sensorimotor cortex and use it to move a cursor to a target on a video screen. The speed and accuracy of cursor movement depend on the consistency of the control signal and on the signal-to-noise ratio achieved by the spatial and temporal filtering methods that extract the activity prior to its translation into cursor movement. The present study compared alternative spatial filtering methods. Sixty-four channel EEG data collected while well-trained subjects were moving the cursor to targets at the top or bottom edge of a video screen were analyzed offline by four different spatial filters, namely a standard ear-reference, a common average reference (CAR), a small Laplacian (3 cm to set of surrounding electrodes) and a large Laplacian (6 cm to set of surrounding electrodes). The CAR and large Laplacian methods proved best able to distinguish between top and bottom targets. They were significantly superior to the ear-reference method. The difference in performance between the large Laplacian and small Laplacian methods presumably indicated that the former was better matched to the topographical extent of the EEG control signal. The results as a whole demonstrate the importance of proper spatial filter selection for maximizing the signal-to-noise ratio and thereby improving the speed and accuracy of EEG-based communication.10aassistive communication10aElectroencephalography10amu rhythm10aoperant conditioning10aprosthesis10aRehabilitation10asensorimotor cortex1 aMcFarland, Dennis, J.1 aMcCane, L., M.1 aDavid, S., V.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/930528702490nas a2200265   4500008004100000022001400041245004000055210003800095260001200133300001400145490000700159520177200166653002801938653002701966653001401993653002502007653001502032653001902047653002402066100002102090700001902111700002102130700002602151856004702177       1997                        eng d  a0736-025800aTiming of EEG-based cursor control.0 aTiming of EEGbased cursor control  c11/1997  a529–5380 v143 aRecent studies show that humans can learn to control the amplitude of electroencephalography (EEG) activity in specific frequency bands over sensorimotor cortex and use it to move a cursor to a target on a computer screen. EEG-based communication could be a valuable new communication and control option for those with severe motor disabilities. Realization of this potential requires detailed knowledge of the characteristic features of EEG control. This study examined the course of EEG control after presentation of a target. At the beginning of each trial, a target appeared at the top or bottom edge of the subject's video screen and 1 sec later a cursor began to move vertically as a function of EEG amplitude in a specific frequency band. In well-trained subjects, this amplitude was high at the time the target appeared and then either remained high (i.e., for a top target) or fell rapidly (i.e., for a bottom target). Target-specific EEG amplitude control began 0.5 sec after the target appeared and appeared to wax and wane with a period of approximately 1 sec until the cursor reached the target (i.e., a hit) or the opposite edge of the screen (i.e., a miss). Accuracy was 90% or greater for each subject. Top-target errors usually occurred later in the trial because of failure to reach and/or maintain sufficiently high amplitude, whereas bottom-target errors usually occurred immediately because of failure to reduce an initially high amplitude quickly enough. The results suggest modifications that could improve performance. These include lengthening the intertrial period, shortening the delay between target appearance and cursor movement, and including time within the trial as a variable in the equation that translates EEG into cursor movement.10aassistive communication10aElectroencephalography10amu rhythm10aoperant conditioning10aprosthesis10aRehabilitation10asensorimotor cortex1 aWolpaw, Jonathan1 aFlotzinger, D.1 aPfurtscheller, G1 aMcFarland, Dennis, J.  uhttp://www.ncbi.nlm.nih.gov/pubmed/945806001454nas a2200181   4500008004100000022001400041245005300055210005000108260001200158300001400170490000600184520094700190653002201137100002401159700002101183700002101204856004701225       1996                        eng d  a1063-652800aEEG-based communication: prospects and problems.0 aEEGbased communication prospects and problems  c12/1996  a425–4300 v43 aCurrent rehabilitation engineering combines new prosthetic methods with recent developments in personal computers to provide alternative communication and control channels to individuals with motor impairments. Despite these advances, all commercially available systems still require some measure of voluntary motor control. Thus, these systems are not useful for individuals who are totally paralyzed. Electroencephalographic (EEG) activity may provide the basis for a system that would completely bypass normal motor output. EEG-based communication technology might provide assistive devices for individuals who have little or no reliable motor function. This paper reviews the prospects for and problems of EEG-based communication. It summarizes current approaches to development of this new technology, describes the major problems that must be resolved, and focuses on issues critical for its use by those with severe motor disabilities.10aVisual Perception1 aVaughan, Theresa, M1 aWolpaw, Jonathan1 aDonchin, Emanuel  uhttp://www.ncbi.nlm.nih.gov/pubmed/897396902569nas a2200169   4500008004100000022001400041245008800055210006900143260001200212300001600224490000700240520204900247653001302296100002202309700002102331856004702352       1996                        eng d  a0027-842400aOperant conditioning of H-reflex changes synaptic terminals on primate motoneurons.0 aOperant conditioning of Hreflex changes synaptic terminals on pr  c08/1996  a9206–92110 v933 aOperant conditioning of the primate triceps surae H-reflex, the electrical analog of the spinal stretch reflex, creates a memory trace that includes changes in the spinal cord. To define the morphological correlates of this plasticity, we analyzed the synaptic terminal coverage of triceps surae motoneurons from animals in which the triceps surae H-reflex in one leg had been increased (HRup mode) or decreased (HRdown mode) by conditioning and compared them to each other and to motoneurons from unconditioned animals. Motoneurons were labeled by intramuscular injection of cholera toxin-horseradish peroxidase. A total of 5055 terminals on the cell bodies and proximal dendrites of 114 motoneurons from 14 animals were studied by electron microscopy. Significant differences were found between HRup and HRdown animals and between HRup and naive (i.e., unconditioned) animals. F terminals (i.e., putative inhibitory terminals) were smaller and their active zone coverage on the cell body was lower on motoneurons from the conditioned side of HRup animals than on motoneurons from the conditioned side of HRdown animals. C terminals (i.e., terminals associated with postsynaptic cisterns and rough endoplasmic reticulum) were smaller and the number of C terminals in each C complex (i.e., a group of contiguous C terminals) was larger on motoneurons from the conditioned side of HRup animals than on motoneurons either from the conditioned side of HRdown animals or from naive animals. Because the treatment of HRup and HRdown animals differed only in the reward contingency, the results imply that the two contingencies had different effects on motoneuron synaptic terminals. In combination with other recent data, they show that H-reflex conditioning produces a complex pattern of spinal cord plasticity that includes changes in motoneuron physiological properties as well as in synaptic terminals. Further delineation of this pattern should reveal the contribution of the structural changes described here to the learned change in behavior.10aSynapses1 aFeng-Chen, K., C.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/879917902267nas a2200253   4500008004100000022001400041245006600055210006300121260001200184300001400196490000700210520156600217653001301783653002501796653001501821653000801836653001801844653002301862100002101885700002101906700002001927700001901947856004701966       1996                        eng d  a0897-715100aOperant conditioning of H-reflex in spinal cord-injured rats.0 aOperant conditioning of Hreflex in spinal cordinjured rats  c12/1996  a755–7660 v133 aOperant conditioning of the spinal stretch reflex or its electrical analog, the H-reflex, is a new model for exploring the mechanisms of supraspinal control over spinal cord function. Both rats and primates can gradually increase (HRup conditioning mode) or decrease (HRdown conditioning mode) soleus H-reflex magnitude when exposed to an operant conditioning task. This study used H-reflex operant conditioning to assess and modify spinal cord function after injury. Soleus H-reflexes were elicited and recorded with chronically implanted electrodes from rats that had been subjected to calibrated contusion injuries to the spinal cord at T8. From 18 to 140 days after injury, background EMG, M response amplitude, and initial H-reflex amplitude were not significantly different from those of normal rats. HRdown conditioning was successful in some, but not all, spinal cord-injured rats. The H-reflex decrease achieved by conditioning was inversely correlated with the severity of the injury as assessed histologically or by time to return of bladder function. It was not correlated with the length of time between injury and the beginning of conditioning. The results confirm the importance of descending control from supraspinal structures in mediating operantly conditioned change in H-reflex amplitude. In conjunction with recent human studies, they suggest that H-reflex conditioning could provide a sensitive new means for assessing spinal cord function after injury, and might also provide a method for initiating and guiding functional rehabilitation.10aH-Reflex10aoperant conditioning10aplasticity10arat10asoleus muscle10aspinal cord injury1 aChen, Xiang Yang1 aWolpaw, Jonathan1 aJakeman, L., B.1 aStokes, B., T.  uhttp://www.ncbi.nlm.nih.gov/pubmed/900206101790nas a2200229   4500008004100000022001400041245005800055210005600113260001200169300001200181490000800193520117500201653001301376653002501389653001501414653000801429653001801437653001601455100002101471700002101492856004701513       1996                        eng d  a0014-481900aReversal of H-reflex operant conditioning in the rat.0 aReversal of Hreflex operant conditioning in the rat  c11/1996  a58–620 v1123 aIn response to an operant conditioning task, rats can gradually increase or decrease soleus H-reflex amplitude without change in background electromyographic activity or M response amplitude. Both increase (under the HRup mode) and decrease (under the HRdown mode) develop over weeks. The present study investigated reversal of conditioned H-reflex change. Following collection of control data, rats were exposed to one mode (HRup or HRdown) for 50 days, and then exposed to the opposite mode for up to 72 days. Rats responded to each mode exposure with gradual, mode-appropriate change in H-reflex amplitude. This finding is consistent with other evidence that H-reflex conditioning depends on spinal cord plasticity. The effects of exposure to the HRup (or HRdown) mode were not affected by whether exposure followed previous exposure to the HRdown (or HRup) mode. In accord with recent studies suggesting that HRup and HRdown conditioning have different spinal mechanisms, these results suggest that reversal of H-reflex change is due primarily to the superimposition of additional plasticity rather than to decay of the plasticity responsible for the initial change.10aH-Reflex10aoperant conditioning10aplasticity10arat10asoleus muscle10aSpinal Cord1 aChen, Xiang Yang1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/895140702345nas a2200229   4500008004100000022001400041245005800055210005700113260001200170300001400182490000600196520170800202653002201910100002001932700002201952700002001974700001801994700002002012700002102032700001502053856004702068       1996                        eng d  a1063-652800aTherapeutic neural effects of electrical stimulation.0 aTherapeutic neural effects of electrical stimulation  c12/1996  a218–2300 v43 aThe use of a functional neuromuscular stimulation (FNS) device can have therapeutic effects that persist when the device is not in use. Clinicians have reported changes in both voluntary and electrically assisted neuromuscular function and improvements in the condition of soft tissue. Motor recovery has been observed in people with incomplete spinal cord injury, stroke, or traumatic brain injury after the use of motor prostheses. Improvement in voluntary dorsiflexion and overall gait pattern has been reported both in the short term (several hours) and permanently. Electrical stimulation of skin over flexor muscles in the upper limb produced substantial reductions for up to 1 h in the severity of spasticity in brain-injured subjects, as measured by the change in torque generation during ramp-and-hold muscle stretch. There was typically an aggravation of the severity of spasticity when surface stimulation reached intensities sufficient to also excite muscle. Animals were trained to alter the size of the H-reflex to obtain a reward. The plasticity that underlies this operantly conditioned H-reflex change includes changes in the spinal cord itself. Comparable changes appear to occur with acquisition of certain motor skills. Current studies are exploring such changes in humans and animals with spinal cord injuries with the goal of using conditioning methods to assess function after injury and to promote and guide recovery of function. A better understanding of the mechanisms of neural plasticity, achieved through human and animal studies, may help us to design and implement FNS systems that have the potential to produce beneficial changes in the subject's central nervous systems.10aTreatment Outcome1 aDaly, Janis, J.1 aMarsolais, E., B.1 aMendell, L., M.1 aRymer, W., Z.1 aStefanovska, A.1 aWolpaw, Jonathan1 aKantor, C.  uhttp://www.ncbi.nlm.nih.gov/pubmed/897394801530nas a2200205   4500008004100000022001400041245011100055210006900166260000900235300001400244490000700258520087900265653002801144100002101172700001901193700001801212700002101230700002601251856004701277       1995                        eng d  a0047-655200aEEG-based brain computer interface (BCI). Search for optimal electrode positions and frequency components.0 aEEGbased brain computer interface BCI Search for optimal electro  c1996  a111–1210 v213 aSeveral laboratories around the world have recently started to investigate EEG-based brain computer interface (BCI) systems in order to create a new communication channel for subjects with severe motor impairments. The present paper describes an initial evaluation of 64-channel EEG data recorded while subjects used one EEG channel over the left sensorimotor area to control on-line vertical cursor movement. Targets were given at the top or bottom of a computer screen. Data from 3 subjects in the early stages of training were analyzed by calculating band power time courses and maps for top and bottom targets separately. In addition, the Distinction Sensitive Learning Vector Quantizer (DSLVQ) was applied to single-trial EEG data. It was found that for each subject there exist optimal electrode positions and frequency components for on-line EEG-based cursor control.10aUser-Computer Interface1 aPfurtscheller, G1 aFlotzinger, D.1 aPregenzer, M.1 aWolpaw, Jonathan1 aMcFarland, Dennis, J.  uhttp://www.ncbi.nlm.nih.gov/pubmed/877670802073nas a2200169   4500008004100000022001400041245008400055210006900139260001200208300001600220490000700236520155800243653001101801100002301812700002101835856004701856       1995                        eng d  a0022-307700aMotoneuron properties after operantly conditioned increase in primate H-reflex.0 aMotoneuron properties after operantly conditioned increase in pr  c04/1995  a1365–13730 v733 a1. Monkeys can increase (HRup conditioning mode) or decrease (HRdown conditioning mode) the triceps surae (TS) H-reflex in response to an operant conditioning task. This conditioning modifies the spinal cord. To define this spinal cord plasticity and its role in the behavioral change (H-reflex increase or decrease), we have recorded intracellularly from TS motoneurons in conditioned animals. The present report describes data from HRup animals and compares them with data from previously studied naive (NV; i.e., unconditioned) animals. 2. Thirteen monkeys (Macaca nemestrina, male, 3.8-7.1 kg) were exposed to the HRup conditioning mode, in which reward occurred when H-reflex size in one leg (i.e., the trained leg) was above a criterion value. Conditioning was successful (i.e., increase of > or = 20%) in 12 of the 13 animals. At the end of conditioning, H-reflex size in the trained leg averaged 188% of its initial value, whereas size in the control leg averaged 134% of its initial value. 3. Intracellular recordings were obtained from 136 TS motoneurons on trained (UT + motoneurons) and control (UC + motoneurons) sides of the successful animals. Measurements included axonal conduction velocity, input resistance, time constant, electrotonic length, rheobase, firing threshold to current injection, afterhyperpolarization duration and amplitude, and composite homonymous and heteronymous excitatory postsynaptic potential (EPSP) size and shape. Results were compared with intracellular data from NV animals.(ABSTRACT TRUNCATED AT 250 WORDS)10aReward1 aCarp, Jonathan, S.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/754394202025nas a2200169   4500008004100000022001400041245006000055210005800115260001200173300001400185490000700199520154400206653001601750100002101766700002101787856004701808       1995                        eng d  a0022-307700aOperant conditioning of H-reflex in freely moving rats.0 aOperant conditioning of Hreflex in freely moving rats  c01/1995  a411–4150 v733 a1. Primates can increase or decrease the spinal stretch reflex and its electrical analogue, the H-reflex (HR), in response to an operant conditioning task. This conditioning changes the spinal cord itself and thereby provides an experimental model for defining the processes and substrates of a learned change in behavior. Because the phenomenon has been demonstrated only in primates, its generality and theoretical implications remain unclear, and its experimental use is restricted by the difficulties of primate research. In response to these issues, the present study explored operant conditioning of the H-reflex in the rat. 2. Seventeen Sprague-Dawley rats implanted with chronic electromyographic (EMG) recording electrodes in one soleus muscle and nerve cuff stimulating electrodes on the posterior tibial nerve were rewarded (either with medial forebrain bundle stimulation or food) for increasing (HRup conditioning mode) or decreasing (HRdown conditioning mode) soleus H-reflex amplitude without change in background EMG or M response (direct muscle response) amplitude. 3. H-reflex amplitude changed appropriately over 3-4 wk. Under the HRup mode, it rose to an average of 158 +/- 54% (mean +/- SD) of initial value, whereas under the HRdown mode it fell to an average of 67 +/- 11% of initial value. Background EMG and M response amplitude did not change. 4. Operant conditioning of the H-reflex in the rat appears similar in rate and final magnitude of change to that observed in the monkey.(ABSTRACT TRUNCATED AT 250 WORDS)10aSpinal Cord1 aChen, Xiang Yang1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/771458401900nas a2200181   4500008004100000022001400041245008300055210006900138260001200207300001400219490000700233520134800240653002001588100001901608700002301627700002101650856004701671       1995                        eng d  a0022-307700aOperantly conditioned motoneuron plasticity: possible role of sodium channels.0 aOperantly conditioned motoneuron plasticity possible role of sod  c02/1995  a867–8710 v733 a1. Learning is traditionally thought to depend on synaptic plasticity. However, recent work shows that operantly conditioned decrease in the primate H reflex is associated with an increase in the depolarization needed to fire the spinal motoneuron (VDEP) and a decrease in its conduction velocity (CV). Furthermore, the increase in VDEP appears to be largely responsible for the H-reflex decrease. The conjunction of these changes in VDEP and CV suggests that an alteration in Na+ channel properties throughout the soma and axon could be responsible. 2. A mathematical model of the mammalian myelinated axon was used to test whether a positive shift in the voltage dependence of Na+ channel activation, a decrease in Na+ channel peak permeability, or changes in other fiber properties could have accounted for the experimental findings. 3. A positive shift of 2.2 mV in Na+ channel activation reproduced the experimentally observed changes in VDEP and CV, whereas a reduction in Na+ channel permeability or changes in other fiber properties did not. 4. These results are consistent with the hypothesis that operantly conditioned decrease in the primate H reflex is largely due to a positive shift in the voltage dependence of Na+ channel activation. Recent studies suggest that change in activation of protein kinase C may mediate this effect.10aSodium Channels1 aHalter, J., A.1 aCarp, Jonathan, S.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/776014101682nas a2200229   4500008004100000022001400041245010100055210006900156260001200225300001400237490000800251520101200259653002101271653001301292653001301305653001101318653002501329653000901354100002101363700002101384856004701405       1995                        eng d  a0304-394000aOperantly conditioned plasticity and circadian rhythm in rat H-reflex are independent phenomena.0 aOperantly conditioned plasticity and circadian rhythm in rat Hre  c08/1995  a109–1120 v1953 aRecent studies indicate that rats can increase or decrease H-reflex amplitude in response to an operant conditioning paradigm. In addition, rats also display a circadian rhythm in H-reflex amplitude. As part of the development of H-reflex conditioning in the rat as a new model for defining the plasticity underlying a simple form of learning, this study examined the relationship in the rat between operantly conditioned H-reflex change and the H-reflex circadian rhythm. When H-reflex amplitude increased or decreased in response to the operant conditioning program, its circadian rhythm showed no changes in phase and minimal change in amplitude. Furthermore, animals did not alter daily performance schedule so as to use the rhythm to increase reward probability. Thus, in the rat, H-reflex operant conditioning and the H-reflex circadian rhythm appear to be independent phenomena. The circadian rhythm should not be a significant complicating factor in studies of operantly conditioned H-reflex change.10acircadian rhythm10aH-Reflex10aLearning10aMemory10aoperant conditioning10aRats1 aChen, Xiang Yang1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/747826202070nas a2200241   4500008004100000022001400041245009400055210006900149260001200218300001600230490000700246520139200253653001701645653001301662653001101675653001801686653001501704653001201719653001601731653001301747100002101760856004701781       1994                        eng d  a0195-913100aAcquisition and maintenance of the simplest motor skill: investigation of CNS mechanisms.0 aAcquisition and maintenance of the simplest motor skill investig  c12/1994  a1475–14790 v263 aThe spinal stretch reflex (SSR), or tendon jerk, is the simplest behavior of the vertebrate nervous system. It is mediated primarily by a wholly spinal, two-neuron pathway. Recent studies from several laboratories have shown that primates, human and nonhuman, can gradually increase or decrease the size of the SSR when reward depends on such change. Evidence of this training remains in the spinal cord after all supraspinal influence is removed. Thus, the learning of this simple motor skill changes the spinal cord itself. Comparable spinal plasticity probably plays a role in the acquisition of many complex motor skills. Intracellular physiological and anatomical studies are seeking the location and nature of this spinal cord plasticity. Attention focuses on the most probable sites of change, the group Ia afferent synapse on the alpha motoneuron and the motoneuron itself. Results to date indicate that modifications are present at several places in the spinal cord. Current clinical studies are investigating the use of spinal cord adaptive plasticity as a basis for a new therapeutic approach to spasticity and other forms of abnormal spinal reflex function that result from spinal cord injury, stroke, or other neurological disorders. In the future, understanding of spinal reflex plasticity may lead to development of improved training methods for a variety of motor skills.10aconditioning10aLearning10aMemory10aMotor control10aplasticity10aprimate10aSpinal Cord10atraining1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/786988201137nas a2200217   4500008004100000022001400041245003800055210003600093260001200129300001400141490000800155520059500163653002100758653001900779653001300798653000800811653001100819100002100830700002100851856004700872       1994                        eng d  a0006-899300aCircadian rhythm in rat H-reflex.0 aCircadian rhythm in rat Hreflex  c06/1994  a167–1700 v6483 aWe measured soleus H-reflex in the Sprague-Dawley rat as a function of time of day. H-reflex amplitude displayed a marked diurnal variation, even though background EMG and M-response amplitude were stable through the day. The H-reflex was largest in the late morning and smallest around midnight. Thus, its rhythm was opposite in phase to the circadian rhythm found in the primate H-reflex. This rhythm is a potentially confounding factor in studies of motor function. Furthermore, its existence implies that the CNS activity underlying a specific motor performance varies with time of day.10acircadian rhythm10aelectromyogram10aH-Reflex10arat10asoleus1 aChen, Xiang Yang1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/792252000588nas a2200157   4500008004100000022001400041245017200055210006900227260001200296300001200308490000700320653001100327100002100338700002400359856004700383       1994                        eng d  a0013-469400aThe influence of stimulus intensity, contralateral masking and handedness on the temporal N1 and the T complex components of the auditory N1 wave, by John F. Connolly.0 ainfluence of stimulus intensity contralateral masking and handed  c07/1994  a71–760 v9110aHumans1 aWolpaw, Jonathan1 aCacace, Anthony, T.  uhttp://www.ncbi.nlm.nih.gov/pubmed/751784703057nas a2200169   4500008004100000022001400041245008900055210006900144260001200213300001400225490000700239520252400246653002602770100002302796700002102819856004702840       1994                        eng d  a0022-307700aMotoneuron plasticity underlying operantly conditioned decrease in primate H-reflex.0 aMotoneuron plasticity underlying operantly conditioned decrease   c07/1994  a431–4420 v723 a1. Monkeys can gradually increase or decrease the size of the triceps surae H-reflex in response to an operant conditioning task. This conditioning modifies the spinal cord. To determine the location and nature of the spinal cord plasticity and define its role in the behavioral change (i.e., H-reflex increase or decrease) we have recorded intracellularly from triceps surae motoneurons in conditioned animals and compared the results with data from naive (i.e., unconditioned) animals. 2. Eleven monkeys (Macaca nemestrina, male) were exposed to the HRdown conditioning mode, in which reward occurred when H-reflex size in one leg (i.e., the trained leg) was below a criterion value. In six animals (5.1-8.2 kg) H-reflex size in the trained leg fell to 24-58% of its initial value, whereas in the other five animals (4.0-5.5 kg) it remained at 92-114% of its initial value. This outcome, which was in accord with recent data indicating that success in HRdown conditioning is age dependent, allowed comparison of intracellular data from successful HRdown animals with data from unsuccessful animals as well as with data from naive (i.e., unconditioned) animals. 3. Intracellular recordings were obtained from 221 triceps surae motoneurons on trained and control sides of successful and unsuccessful HRdown animals. Measurements included axonal conduction velocity, input resistance, time constant, electrotonic length, rheobase, firing threshold, afterhyperpolarization duration and amplitude, and composite homonymous and heteronymous excitatory postsynaptic potentials to peripheral nerve stimulation. Results were compared with data from 109 triceps surae motoneurons in naive animals. 4. Motoneurons from the trained side of successful HRdown animals had a significantly more positive average firing threshold (-52 vs. -55 mV) and a significantly lower average conduction velocity (67 vs. 71 m/s) than those from naive animals. In contrast, motoneurons from the trained side of unsuccessful HRdown animals were not significantly different from naive motoneurons. 5. These data are consistent with the hypothesis that operantly conditioned decrease in H-reflex size is due to a positive shift in motoneuron firing threshold and a consequent increase in the depolarization needed to reach that threshold. 6. The more positive firing threshold, if present in the axon as well as in the soma, could also account for the decreased conduction velocity observed in motoneurons from the trained side of successful animals.10aSynaptic Transmission1 aCarp, Jonathan, S.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/796502501539nas a2200241   4500008004100000022001400041245005700055210005400112260001200166300001400178490000700192520085200199653002801051653002701079653001401106653002501120653001501145653001901160653002401179100002101203700002601224856004701250       1994                        eng d  a0013-469400aMultichannel EEG-based brain-computer communication.0 aMultichannel EEGbased braincomputer communication  c06/1994  a444–4490 v903 aIndividuals who are paralyzed or have other severe movement disorders often need alternative means for communicating with and controlling their environments. In this study, human subjects learned to use two channels of bipolar EEG activity to control 2-dimensional movement of a cursor on a computer screen. Amplitudes of 8-12 Hz activity in the EEG recorded from the scalp across right and left central sulci were determined by fast Fourier transform and combined to control vertical and horizontal cursor movements simultaneously. This independent control of two separate EEG channels cannot be attributed to a non-specific change in brain activity and appeared to be specific to the mu rhythm frequency range. With further development, multichannel EEG-based communication may prove of significant value to those with severe motor disabilities.10aassistive communication10aElectroencephalography10amu rhythm10aoperant conditioning10aprosthesis10aRehabilitation10asensorimotor cortex1 aWolpaw, Jonathan1 aMcFarland, Dennis, J.  uhttp://www.ncbi.nlm.nih.gov/pubmed/751578701909nas a2200181   4500008004100000022001400041245006900055210006600124260001200190300001400202490000800216520138400224653001701608100002101625700002101646700001301667856004701680       1994                        eng d  a0304-394000aOperant conditioning of primate H-reflex: phases of development.0 aOperant conditioning of primate Hreflex phases of development  c04/1994  a203–2070 v1703 aThis study sought to determine whether operantly conditioned change in the primate triceps surae (TS) H-reflex develops in distinct phases. Data from 20 animals in which the TS H-reflex in one leg was trained up (i.e., HRup mode) and 18 in which it was trained down (i.e., HRdown mode) were averaged to define H-reflex behavior in trained and control legs. In HRup animals, the trained-leg H-reflex showed a large phase I increase in the first two days followed by gradual phase II increase that continued for weeks. The control-leg H-reflex appeared to show much smaller phase I and phase II increases. In HRdown animals, the trained-leg H-reflex decreased gradually over weeks, while the control-leg H-reflex appeared to increase within 2 days and did not change from then on. The initial rapid increase in the HRdown control leg suggested that two early events occurred in the HRdown trained leg: a nonspecific increase like that in the control leg and an operantly conditioned mode-specific decrease. These two effects may have obscured each other, so that H-reflex size in the HRdown trained leg did not drop rapidly in the first few days. These results improve understanding of adaptive H-reflex change as an operantly conditioned phenomenon, and provide encouragement and direction for efforts to reproduce and study the phenomenon in reduced or anesthetized preparations.10aTime Factors1 aWolpaw, Jonathan1 aManiccia, D., M.1 aElia, T.  uhttp://www.ncbi.nlm.nih.gov/pubmed/805818803248nas a2200169   4500008004100000022001400041245006900055210006800124260001200192300001400204490000800218520275000226653001602976100001802992700002103010856004703031       1994                        eng d  a0021-996700aSynaptic terminal coverage of primate triceps surae motoneurons.0 aSynaptic terminal coverage of primate triceps surae motoneurons  c07/1994  a345–3580 v3453 aThis study examined the synaptic terminal coverage of primate triceps surae (TS) motoneurons at the electron microscopic level. In three male pigtail macaques, motoneurons were labeled by retrograde transport of cholera toxin-horseradish peroxidase that was injected into TS muscles bilaterally and visualized with tetramethylbenzidine stabilized with diaminobenzidine. Somatic, proximal dendritic, and distal dendritic synaptic terminals were classified by standard criteria and measured. Overall and type-specific synaptic terminal coverages and frequencies were determined. Labeled cells were located in caudal L5 to rostral S1 ventral horn and ranged from 40 to 74 microns in diameter (average, 54 microns). The range and unimodal distribution of diameters, the label used, and the presence of C terminals on almost all cells indicated that the 15 cell bodies and associated proximal dendrites analyzed here probably belonged to alpha-motoneurons. Synaptic terminals covered 39% of the cell body membrane, 60% of the proximal dendritic membrane, and 40% of the distal dendritic membrane. At each of these three sites, F terminals (flattened or pleomorphic vesicles, usually symmetric active zones, average contact length 1.6 microns) were most common, averaging 52%, 56%, and 58% of total coverage and 56%, 57%, and 58% of total number of cell bodies, proximal dendrites, and distal dendrites respectively. S terminals (round vesicles, usually asymmetric active zones, average contact length 1.3 microns) averaged 24%, 29%, and 33% of coverage and 33%, 35%, and 36% of number at these three sites, respectively. Thus, S terminals were slightly more prominent relative to F terminals on distal dendrites than on cell bodies. C terminals (spherical vesicles, subsynaptic cisterns associated with rough endoplasmic reticulum, average contact length 3.5 microns) constituted 24% and 11% of total terminal coverage on cell bodies and proximal dendrites, respectively, and averaged 11% and 6% of terminal number at these two locations. M terminals (spherical vesicles, postsynaptic Taxi bodies, some with presynaptic terminals, average contact length 2.7 microns) were absent on cell bodies and averaged 3% and 7% of total coverage and 2% and 5% of terminals on proximal and distal dendrites, respectively. Except for M terminals, which tended to be smaller distally, terminal contact length was not correlated with location. Total and type-specific coverages and frequencies were not correlated with cell body diameter. Primate TS motoneurons are similar to cat TS motoneurons in synaptic terminal morphology, frequency, and distribution. However, primate terminals appear to be smaller, so that the fraction of membrane covered by them is lower.10aSpinal Cord1 aStarr, K., A.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/792990603311nas a2200229   4500008004100000022001400041245009200055210006900147260001200216300001400228490000800242520262900250653002202879653001402901653002702915653002102942653001302963653001602976100002102992700002103013856004703034       1994                        eng d  a0021-996700aTriceps surae motoneuron morphology in the rat: a quantitative light microscopic study.0 aTriceps surae motoneuron morphology in the rat a quantitative li  c05/1994  a143–1570 v3433 aThe rat is now the model of choice for many studies of motor function. However, little quantitative information on the structure of rat motoneurons is available. In conjunction with efforts to define the physiologic and anatomic substrates of operantly conditioned plasticity in the spinal cord, 13 physiologically identified triceps surae motoneurons in the rat lumbar spinal cord were labeled intracellularly with horseradish peroxidase and completely reconstructed and measured with a computer-based neuron-tracing system. Somata were all located in the ventral horn of lumbar segments 4-5, had an average diameter of 35 microns, and had 6-12 dendrites. Dendrites ramified throughout the ventral horn and also penetrated the white matter. Their spread was greater in the rostrocaudal and dorsoventral directions (1.53 +/- 0.24 mm and 1.35 +/- 0.23 mm, respectively) than in the mediolateral direction (0.85 +/- 0.14 mm). Regardless of soma location, dendritic fields usually extended throughout the ipsilateral coronal cross-section of the ventral horn. As a result, the ventral or lateral extent of the field was correlated strongly with the soma's distance from the ventral or lateral border, respectively, of the ventral horn. Furthermore, although soma locations in the coronal plane varied widely, the centers of the dendritic fields tended to cluster near the center of the ventral horn. Dendrites constituted 96.2-98.4% (mean +/- SD = 97.3 +/- 0.7%) of the total neuronal surface area. Each of the 104 dendrites studied had an average of 13 branch points and 27 segments. First-order segment diameters ranged from 1.4 to 11.7 microns (mean +/- SD = 5.3 +/- 2.1 microns). Total dendritic length, surface area, volume, number of dendritic segments, and maximum segment order were correlated strongly with diameter of the first-order segment. Proceeding distally between branch points, the mean decrease in dendritic diameter (i.e., tapering) +/- the standard deviation was 22 +/- 8% of the proximal diameter. The average ratio +/- the standard deviation of the sum of the average diameters of each daughter segment raised to the 1.5 power to the average diameter of the parent segment raised to the 1.5 power (i.e., Rall's ratio; Rall, 1959) was 0.87 +/- 0.08. In comparison with cat alpha-motoneurons, rat motoneurons had smaller soma diameters, fewer dendrites, smaller total surface areas, and shorter total dendritic lengths. However, the number of terminations per dendrite was similar in the two species, so that rat motoneurons had more terminations per unit dendritic length.(ABSTRACT TRUNCATED AT 400 WORDS)10acomputer assisted10adendrites10ahorseradish peroxidase10aimage processing10aSoftware10aSpinal Cord1 aChen, Xiang Yang1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/802743200429nas a2200157   4500008004100000022001400041245004000055210003900095260000900134300001400143490000700157653001600164100002100180700002300201856004700224       1993                        eng d  a0091-395200aAdaptive plasticity in spinal cord.0 aAdaptive plasticity in spinal cord  c1993  a163–1740 v5910aSpinal Cord1 aWolpaw, Jonathan1 aCarp, Jonathan, S.  uhttp://www.ncbi.nlm.nih.gov/pubmed/842010300741nas a2200253   4500008004100000022001400041245007200055210006900127260001200196300001200208490000700220653002300227100001500250700001800265700002100283700002100304700002000325700001500345700002200360700001600382700001900398700002300417856004700440       1993                        eng d  a0028-762800aEthical and social issues in organ procurement for transplantation.0 aEthical and social issues in organ procurement for transplantati  c01/1993  a30–340 v9310aVoluntary Programs1 aRosner, F.1 aHenry, J., B.1 aWolpaw, Jonathan1 aSordillo, P., P.1 aSechzer, P., H.1 aRogatz, P.1 aRisemberg, H., M.1 aOna, F., V.1 aNumann, P., J.1 aLowenstein, R., E.  uhttp://www.ncbi.nlm.nih.gov/pubmed/842995002325nas a2200229   4500008004100000022001400041245009300055210006900148260001200217300001200229490000700241520165100248653001301899653001101912653002501923653001501948653001601963100002101979700002502000700002302025856004702048       1993                        eng d  a0014-481900aOperant conditioning of the primate H-reflex: factors affecting the magnitude of change.0 aOperant conditioning of the primate Hreflex factors affecting th  c12/1993  a31–390 v973 aPrimates can gradually increase or decrease H-reflex amplitude in one leg when reward depends on that amplitude. The magnitude of change varies greatly from animal to animal. This study sought to define the factors that control this magnitude. It evaluated the influence of animal age, muscle size (absolute and relative), background electromyographic activity (EMG) level, M response amplitude, initial H-reflex amplitude, performance intensity, and behavior of the contralateral leg. Fifty-four animals (Macaca nemestrina) underwent operant conditioning of the triceps surae H-reflex in one leg (the trained leg). Twenty-eight were rewarded for larger H-reflexes (HRup animals), and 26 were rewarded for smaller H-reflexes (HRdown animals). In the HRup animals, H-reflex amplitude in the trained leg rose to an average final value of 177% of its initial amplitude. Magnitude of increase varied widely across animals. Nine animals rose to 120-140%, 11 to 160-240%, three to 300% or more, and five remained within 20% of initial amplitude. In the HRdown animals, H-reflex amplitude in the trained leg decreased to an average of 69% of initial amplitude. Magnitude of decrease varied widely. Five animals decreased to 20-40%, seven to 40-60%, six to 60-80%, and eight remained within 20% of initial amplitude. Animal age, as assessed by weight, markedly affected HRdown conditioning, but not HRup conditioning. Heavy HRdown animals (> or = 6 kg) were more successful than light HRdown animals (< 6 kg). Thirteen of 14 heavy animals and only five of 12 light animals decreased to less than 80% of initial amplitude.(ABSTRACT TRUNCATED AT 250 WORDS)10aH-Reflex10amonkey10aoperant conditioning10aplasticity10aSpinal Cord1 aWolpaw, Jonathan1 aHerchenroder, P., A.1 aCarp, Jonathan, S.  uhttp://www.ncbi.nlm.nih.gov/pubmed/813183001213nas a2200313   4500008004100000022001400041245005000055210004500105300001400150490000700164520043400171653001300605653001000618653001700628653002100645653001300666653001100679653001500690653001100705653001200716653001100728653001600739653001600755653002200771653001500793100002100808700002300829856004700852       1993                        eng d  a0065-140000aThe volitional nature of the simplest reflex.0 avolitional nature of the simplest reflex  a103–1110 v533 aRecent studies suggest that none of the behaviors of the vertebrate CNS are fixed responses incapable of change. Even the simplest reflex of all, the two-neuron, monosynaptic spinal stretch reflex (SSR), undergoes adaptive change under appropriate circumstances. Operantly conditioned SSR change occurs gradually over days and weeks and is associated with a complex pattern of CNS plasticity at both spinal and supraspinal sites.10abehavior10aBrain10aconditioning10ahuman physiology10aLearning10aMemory10amotoneuron10anature10aprimate10aReflex10aSpinal Cord10aspinal site10asupra spinal site10avertebrate1 aWolpaw, Jonathan1 aCarp, Jonathan, S.  uhttp://www.ncbi.nlm.nih.gov/pubmed/831723801216nas a2200229   4500008004100000022001400041245006700055210006600122260001200188300001400200490000700214520057800221653001600799653001500815653001500830653002100845653000800866100002100874700002300895700002100918856004700939       1992                        eng d  a0014-481900aConstancy of motor axon conduction time during growth in rats.0 aConstancy of motor axon conduction time during growth in rats  c08/1992  a343–3450 v903 aAxon conduction distance, conduction velocity, and conduction time were measured for individual triceps surae motoneurons in Sprague-Dawley rats weighing 230-630 g (i.e., age range 6-16 weeks). Both conduction distance (nerve length) and velocity were closely correlated with weight (r = 0.95 and r = 0.82, respectively). In contrast, conduction time did not change as weight increased nearly threefold. This striking constancy is probably due to a corresponding increase in axon diameter. It could contribute to maintenance of stable motor performance during rapid growth.10adevelopment10amotoneuron10amotor axon10anerve conduction10arat1 aChen, Xiang Yang1 aCarp, Jonathan, S.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/139714800735nas a2200253   4500008004100000022001400041245006600055210006400121260001200185300001400197490000700211653002300218100001500241700002100256700002100277700002300298700002000321700001800341700002000359700002000379700001800399700001700417856004700434       1992                        eng d  a0028-762800aEthical considerations concerning the HIV-positive physician.0 aEthical considerations concerning the HIVpositive physician  c04/1992  a151–1550 v9210aVoluntary Programs1 aRosner, F.1 aSordillo, P., P.1 aWolpaw, Jonathan1 aFarnsworth, P., B.1 aBennett, A., J.1 aBuscaglia, A.1 aCassell, E., J.1 aHalpern, A., L.1 aHenry, J., B.1 aKark, P., R.  uhttp://www.ncbi.nlm.nih.gov/pubmed/159414702018nas a2200265   4500008004100000022001400041245006200055210005600117260001200173300001400185490000700199520128900206653001801495653002101513653000801534653001401542653002501556653001501581653002401596100002101620700002601641700001701667700002101684856004701705       1991                        eng d  a0013-469400aAn EEG-based brain-computer interface for cursor control.0 aEEGbased braincomputer interface for cursor control  c03/1991  a252–2590 v783 aThis study began development of a new communication and control modality for individuals with severe motor deficits. We trained normal subjects to use the 8-12 Hz mu rhythm recorded from the scalp over the central sulcus of one hemisphere to move a cursor from the center of a video screen to a target located at the top or bottom edge. Mu rhythm amplitude was assessed by on-line frequency analysis and translated into cursor movement: larger amplitudes moved the cursor up and smaller amplitudes moved it down. Over several weeks, subjects learned to change mu rhythm amplitude quickly and accurately, so that the cursor typically reached the target in 3 sec. The parameters that translated mu rhythm amplitudes into cursor movements were derived from evaluation of the distributions of amplitudes in response to top and bottom targets. The use of these distributions was a distinctive feature of this study and the key factor in its success. Refinements in training procedures and in the distribution-based method used to translate mu rhythm amplitudes into cursor movements should further improve this 1-dimensional control. Achievement of 2-dimensional control is under study. The mu rhythm may provide a significant new communication and control option for disabled individuals.10aCommunication10acomputer control10aEEG10amu rhythm10aoperant conditioning10aprosthesis10asensorimotor rhythm1 aWolpaw, Jonathan1 aMcFarland, Dennis, J.1 aNeat, G., W.1 aForneris, C., A.  uhttp://www.ncbi.nlm.nih.gov/pubmed/170779801079nas a2200181   4500008004100000022001400041245005300055210005200108260001200160300001400172490000800186520058000194653001600774100002100790700001600811700002300827856004700850       1991                        eng d  a0077-892300aOperantly conditioned plasticity in spinal cord.0 aOperantly conditioned plasticity in spinal cord  c08/1991  a338–3480 v6273 aRecent work has shown that the monosynaptic pathway of the SSR can be operantly conditioned, and that a significant part of the plasticity responsible for the behavioral change resides in the spinal cord. The most likely sites of this activity-driven plasticity are the synapse of the Ia afferent neuron on the motoneuron and/or the motoneuron itself. Because the SSR pathway is the simplest and most accessible stimulus-response pathway in the vertebrate CNS, it may provide a valuable experimental model for elucidating activity-driven CNS changes responsible for learning.10aSpinal Cord1 aWolpaw, Jonathan1 aLee, C., L.1 aCarp, Jonathan, S.  uhttp://www.ncbi.nlm.nih.gov/pubmed/188314300697nas a2200253   4500008004100000022001400041245004800055210004300103260001200146300001400158490000700172653002700179100001500206700002100221700002000242700002200262700001600284700001900300700001300319700002300332700002000355700002100375856004700396       1990                        eng d  a0028-762800aThe allocation of scarce medical resources.0 aallocation of scarce medical resources  c11/1990  a552–5580 v9010aVulnerable Populations1 aRosner, F.1 aSordillo, P., P.1 aSechzer, P., H.1 aRisemberg, H., M.1 aOna, F., V.1 aNumann, P., J.1 aLoeb, L.1 aFarnsworth, P., B.1 aBennett, A., J.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/228750002290nas a2200217   4500008004100000022001400041245008500055210006900140260001200209300001100221490000700232520161000239653001201849653005301861653002401914653002201938100002401960700002001984700002102004856004702025       1990                        eng d  a0013-469400aHuman middle-latency auditory evoked potentials: vertex and temporal components.0 aHuman middlelatency auditory evoked potentials vertex and tempor  c02/1990  a6–180 v773 aWe recorded middle-latency (20-70 msec) auditory evoked potentials (MLAEPs) to monaural and binaural clicks in 30 normal adults (ages 20-49 years) at 32 scalp locations all referred to a balanced non-cephalic reference. Our goal was to define the MLAEP components that were present at comparable latencies and comparable locations across the subject population. Group and individual data were evaluated both as topographic maps and as MLAEPs at selected electrode locations. Three major components occurred between 20 and 70 msec, two well-known peaks centered at the vertex, and one previously undefined peak focused over the posterior temporal area. Pa is a 29 msec positive peak centered at the vertex and present with both monaural and binaural stimulation. Pb is a 53 msec positive peak also centered at the vertex but seen consistently only with binaural and right ear stimulation. TP41 is a 41 msec positive peak focused over both temporal areas. TP41 has not been identified in previous MLAEP studies that concentrated on central scalp locations and/or used active reference electrode sites such as ears or mastoids. Available topographic, intracranial, pharmacologic, and lesion studies indicate that Pa, Pb and TP41 are of neural origin. Whether Pa and/or Pb are produced in Heschl's gyrus, primary auditory cortex, remains unclear. TP41 is probably produced by auditory cortex on the posterior lateral surface of the temporal lobe. It should prove of considerable value in experimental and clinical evaluation of higher level auditory function in particular and of cortical function in general.10a(human)10amiddle-latency auditory evoked potential (MLAEP)10atemporal components10avertex components1 aCacace, Anthony, T.1 aSatya-Murti, S.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/168878601104nas a2200169   4500008004100000022001400041245003400055210003300089260001200122300001400134490000700148520067200155653001600827100002100843700002300864856004700887       1990                        eng d  a0166-223600aMemory traces in spinal cord.0 aMemory traces in spinal cord  c04/1990  a137–1420 v133 aThe complexity and inaccessibility of the vertebrate CNS impede the localization and description of memory traces and the definition of the processes that create them. Recent work has shown that the spinal stretch reflex (SSR), which is produced by a monosynaptic two-neuron pathway, can be operantly conditioned, and that memory traces responsible for this behavioral change reside in the spinal cord. The probable locations are the terminal of the Ia affernt neuron on the motoneuron and/or the motoneuron itself. Because it modifies a simple well-defined and accessible pathway, SSR conditioning may be a valuable experimental model for studying vertebrate memory.10aSpinal Cord1 aWolpaw, Jonathan1 aCarp, Jonathan, S.  uhttp://www.ncbi.nlm.nih.gov/pubmed/169217001398nas a2200241   4500008004100000022001400041245006300055210006100118260001200179300001400191490000700205520074600212653001700958653001300975653001100988653001500999653001201014653001801026653001901044100002101063700002501084856004701109       1990                        eng d  a0165-027000aOperant conditioning of H-reflex in freely moving monkeys.0 aOperant conditioning of Hreflex in freely moving monkeys  c02/1990  a145–1520 v313 aThe H-reflex, the electrical analog of the stretch reflex or tendon jerk, is the simplest behavior of the primate CNS. It is subserved by a wholly spinal two-neuron reflex arc. Recent studies show that this reflex can be increased or decreased by operant conditioning, and that such conditioning causes plastic changes in the spinal cord itself. Thus, H-reflex conditioning provides a powerful new model for investigating primate memory traces. The key feature of this model, the conditioning task, originally required animal restraint. This report describes a new tether-based design that allows H-reflex measurement and conditioning without restraint. This design integrates the conditioning task into the life of the freely moving animal.10aconditioning10aH-Reflex10aMemory10aplasticity10aprimate10aspinal reflex10astretch reflex1 aWolpaw, Jonathan1 aHerchenroder, P., A.  uhttp://www.ncbi.nlm.nih.gov/pubmed/231981502188nas a2200181   4500008004100000022001400041245009900055210006900154260001200223300001400235490000700249520162000256653002801876100001901904700002101923700001501944856004701959       1989                        eng d  a0197-846200aChronic exposure of primates to 60-Hz electric and magnetic fields: II. Neurochemical effects.0 aChronic exposure of primates to 60Hz electric and magnetic field  c01/1989  a289–3010 v103 aWe exposed Macaca nemestrina (pig-tailed macaques) to electric (E) and magnetic (B) fields ranging in intensity from 3 kV/m and 0.1 G to 30 kV/m and 0.9 G for three 21-day (d) periods. Experimental animals were exposed to sham E and B fields for two 21-d periods, one prior to and one following actual exposure to E and B fields, resulting in a total of five 21-d periods. Control animals were exposed to sham E and B fields for the entire 105-d interval. At the end of each 21-d period cerebrospinal fluid (CSF) was obtained by lumbar puncture and analyzed for concentrations of homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA), metabolites of dopamine and serotonin neurotransmitters, respectively, by high-performance liquid chromatography with electrochemical detection (HPLC-ECD). Results are based on an examination of six experimental and four control animals. Exposure to E and B fields at all strengths was associated with a significant decline in CSF concentrations of both HVA and 5-HIAA when statistical comparisons were made against values obtained at the end of the preexposure interval. However, HVA returned to preexposure levels during the postexposure period, while 5-HIAA did not. No significant change in the concentrations of HVA or 5-HIAA was noted in the control animals. These results strongly suggest that exposure of the nonhuman primate to E and B fields can significantly affect specific biochemical estimates of nervous system function. These effects may involve alterations either in neuronal activity or in the activity of enzymes that catabolize the neurotransmitters.10aNeurotransmitter Agents1 aSeegal, R., F.1 aWolpaw, Jonathan1 aDowman, R.  uhttp://www.ncbi.nlm.nih.gov/pubmed/247375501807nas a2200229   4500008004100000022001400041245014300055210006900198260001200267300001400279490000700293520108100300653001701381653002701398653001901425653001901444653001201463100002101475700001901496700001501515856004701530       1989                        eng d  a0197-846200aChronic exposure of primates to 60-Hz electric and magnetic fields: I. Exposure system and measurements of general health and performance.0 aChronic exposure of primates to 60Hz electric and magnetic field  c01/1989  a277–2880 v103 aWe exposed pigtailed macaques (Macaca nemestrina) to electric (E) and magnetic (B) fields at strengths of 3 kV/m and 0.1 G, 10 kV/m and 0.3 G, and 30 kV/m and 0.9 G for three 21 day segments. These three exposure segments were preceded and followed by 21 day sham exposure segments. Additional animals received only sham exposure for five 21 day segments. Detailed description of the exposure chamber and field generation apparatus is given. We evaluated measures of animal well-being, including weight, blood chemistry, blood cell counts, and performance on a simple motor task, and performed postmortem examinations. Reliable and consistent results were obtained throughout data collection. None of the measures evaluated was significantly affected by E- and B-field exposures. Data obtained during actual exposure segments were not distinguishable from those obtained during the initial and final sham exposure segments, nor were they different from data obtained from the sham-exposed animals. Thus, field exposure had no apparent effects on general health or performance.10a60-Hz fields10acentral nervous system10aelectric field10amagnetic field10aprimate1 aWolpaw, Jonathan1 aSeegal, R., F.1 aDowman, R.  uhttp://www.ncbi.nlm.nih.gov/pubmed/275170202268nas a2200265   4500008004100000022001400041245010300055210006900158260001200227300001400239490000700253520148500260653003601745653001301781653002301794653002101817653001301838653001801851653001101869100001501880700002101895700001901916700002001935856004701955       1989                        eng d  a0197-846200aChronic exposure of primates to 60-Hz electric and magnetic fields: III. Neurophysiologic effects.0 aChronic exposure of primates to 60Hz electric and magnetic field  c01/1989  a303–3170 v103 aThe neurophysiologic effects of combined 60-Hz electric (E) and magnetic (B) fields, of magnitudes comparable to those produced by high-voltage powerlines, were investigated in 10 monkeys (Macaca nemestrina). Six animals (experimental group) were each exposed to three different levels of E and B fields: 3 kV/m and 0.1 G, 10 kV/m and 0.3 G, and 30 kV/m and 0.9 G. Field exposures were preceded and followed by sham exposures, during which factors of field generation were present (e.g., heat, vibration, noise, etc.) without E and B fields. Each of the five segments (i.e., the three exposure segments and the initial and final sham exposure segments) lasted 3 weeks. Animals were exposed for 18 h/day (fields on at 1600 h, off at 1000 h). Four other animals (external control group) were given sham exposure for the entire 15-week period. Auditory, visual, and somatosensory evoked potentials were recorded twice a week, during the daily 6-h field-off period. E- and B-field exposure had no effect on the early or mid-latency evoked potential components, suggesting that exposure at these levels has no effect on peripheral or central sensory afferent pathways. However, there was a statistically significant decrease in the amplitudes of late components of the somatosensory evoked potential during the 10kV/m and 0.3 G, and 30 kV/m and 0.9 G exposure levels. This result is possibly related to the opiate antagonist effect of electromagnetic field exposure reported by others.10a60-Hz electromagnetic radiation10aauditory10abrainstem auditory10aevoked potential10aprimates10asomatosensory10avisual1 aDowman, R.1 aWolpaw, Jonathan1 aSeegal, R., F.1 aSatya-Murti, S.  uhttp://www.ncbi.nlm.nih.gov/pubmed/275170301922nas a2200169   4500008004100000022001400041245010600055210006900161260001200230300001200242490000700254520139200261653001601653100001501669700002101684856004701705       1989                        eng d  a0013-469400aDiurnal rhythms in primate spinal reflexes and accompanying cortical somatosensory evoked potentials.0 aDiurnal rhythms in primate spinal reflexes and accompanying cort  c01/1989  a69–800 v723 aWe recorded spinal reflexes and cortical somatosensory evoked potentials (SEPs), elicited by stretching the biceps or the triceps muscle or by electrically stimulating the posterior tibial nerve, from monkeys throughout the day. Amplitudes of the spinal stretch reflex (SSR) and of its electrically evoked analogue, the H-reflex, varied diurnally: both were greatest midway through the lights-off period and smallest during the lights-on period. Stretch-evoked and electrically evoked SEP amplitudes also varied diurnally, but were out of phase with the spinal reflex rhythms. The H-reflex is elicited by direct stimulation of the nerve and thus, unlike the SSR, bypasses the muscle spindle. The H-reflex diurnal rhythm and the phase difference between the spinal reflex and SEP diurnal rhythms indicate that these rhythms are mediated at least in part by central mechanisms. Furthermore, both the spinal reflex and SEP diurnal rhythms appeared to be entrained by the light-dark cycle, which suggests that they may be coupled to the same oscillator. Besides their theoretical importance, these rhythms have important implications for experimental and clinical studies of spinal reflexes and SEPs. These rhythms are especially pertinent to the interpretation of long-term monitoring studies, as are often carried out in the Intensive Care Unit and during lengthy neurosurgical procedures.10aSpinal Cord1 aDowman, R.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/246447703194nas a2200169   4500008004100000022001400041245008700055210006900142260001200211300001400223490000700237520268000244653001602924100002102940700001602961856004702977       1989                        eng d  a0022-307700aMemory traces in primate spinal cord produced by operant conditioning of H-reflex.0 aMemory traces in primate spinal cord produced by operant conditi  c03/1989  a563–5720 v613 a1. Study of memory traces in higher animals requires experimental models possessing well-localized and technically accessible memory traces–plasticity responsible for behavioral change, not dependent on control from elsewhere, and open to detailed investigation. Our purpose has been to develop such a model based on the wholly spinal, largely monosynaptic path of the spinal stretch reflex. Previous studies described operant conditioning of this reflex and of its electrical analog, the H-reflex. In this study, we sought to determine whether conditioning causes changes in the spinal cord that affect the reflex and are not dependent on continued supraspinal influence, and thus qualify as memory traces. 2. Sixteen monkeys underwent chronic conditioning of the triceps surae H-reflex. Eight were rewarded for increasing H-reflex amplitude (HR increases mode), and eight were rewarded for decreasing it (HR decreases mode). In each animal, the other leg was an internal control. Over several months of conditioning, H-reflex amplitude in the conditioned leg rose in HR increases animals and fell in HR decreases animals. H-reflex amplitude in the control leg changed little. 3. After HR increases or HR decreases conditioning, each animal was deeply anesthetized and surgically prepared. The reflex response to supramaximal dorsal root stimulation was measured from the triceps surae nerve as percent of response to supramaximal ventral root stimulation, which was the maximum possible response. Data from both legs were collected before and for up to 3 days after thoracic (T9-10) cord transection. The animal remained deeply anesthetized throughout and was killed by overdose. 4. The reflex asymmetries produced by conditioning were still present several days after transection removed supraspinal influence: reflexes of HR increases animals were significantly larger in HR increases legs than in control legs and reflexes of HR decreases animals were significantly smaller in HR decreases legs than in control legs. 5. Reflex amplitude was much greater in the control legs of anesthetized HR decreases animals than in the control legs of anesthetized HR increases animals. 6. Chronic conditioning had at least two effects on the spinal cord. The first effect, task-appropriate reflex asymmetry, was evident both in the awake behaving animal and in the anesthetized transected animal. The second effect, larger control leg reflexes in HR decreases than in HR increases animals, was evident only in the anesthetized animal. By removing supraspinal control, anesthesia and transection revealed a previously hidden effect of conditioning.(ABSTRACT TRUNCATED AT 400 WORDS)10aSpinal Cord1 aWolpaw, Jonathan1 aLee, C., L.  uhttp://www.ncbi.nlm.nih.gov/pubmed/270910001769nas a2200253   4500008004100000022001400041245010600055210006900161260001200230300001400242490000800256520104100264653001701305653001301322653001101335653001501346653001701361653001201378653001801390100002101408700002301429700001601452856004701468       1989                        eng d  a0304-394000aMemory traces in spinal cord produced by H-reflex conditioning: effects of post-tetanic potentiation.0 aMemory traces in spinal cord produced by Hreflex conditioning ef  c08/1989  a113–1190 v1033 aOperant conditioning of the wholly spinal, largely monosynaptic triceps surae H-reflex in monkeys causes changes in lumbosacral spinal cord that persist after removal of supraspinal influence. We evaluated the interaction between post-tetanic potentiation and these memory traces. Animals in which the triceps surae H-reflex in one leg had been increased or decreased by conditioning were deeply anesthetized, and monosynaptic reflexes to L6-S1 dorsal root stimulation were recorded before and after tetanization from both legs for 3 days after thoracic cord transection. Animals remained anesthetized throughout and were sacrificed by overdose. Reflex asymmetries consistent with the effect of H-reflex conditioning were present after transection and persisted through the 3 days of study. Tetanization affected conditioned leg and control leg reflexes similarly. This finding suggests that, while post-tetanic potentiation and probably H-reflex conditioning alter Ia synaptic transmission, the two phenomena have different mechanisms.10aconditioning10aLearning10aMemory10amotoneuron10apotentiation10aprimate10aspinal reflex1 aWolpaw, Jonathan1 aCarp, Jonathan, S.1 aLee, C., L.  uhttp://www.ncbi.nlm.nih.gov/pubmed/277985201794nas a2200253   4500008004100000022001400041245008600055210006900141260001200210300001200222490000700234520107100241653001301312653001101325653002401336653002501360653001501385653001601400653001801416100002101434700001601455700002201471856004701493       1989                        eng d  a0014-481900aOperant conditioning of primate triceps surae H-reflex produces reflex asymmetry.0 aOperant conditioning of primate triceps surae Hreflex produces r  c03/1989  a35–390 v753 aMonkeys are able to increase or decrease triceps surae H-reflex when reward depends on reflex amplitude. Operantly conditioned change occurs over weeks and produces persistent alterations in the lumbosacral spinal cord which should be technically accessible substrates of primate memory. Previous work monitored and conditioned triceps surae H-reflex in one leg. To determine whether H-reflex conditioning in one leg affects the control leg, the present study monitored H-reflexes in both legs while the reflex in one leg underwent HR increases or HR decreases conditioning. Under the HR increases mode, H-reflex increase was much greater in the HR increases leg than in the control leg. Under the HR decreases mode, H-reflex decrease was confined to the HR decreases leg. By showing that conditioning of one leg's H-reflex produces H-reflex asymmetry, the data further define the phenomenon and indicate that the other leg can serve as an internal control for physiologic and anatomic studies exploring the sites and mechanisms of the spinal cord memory substrates.10aLearning10aMemory10amonosynaptic reflex10aoperant conditioning10aplasticity10aSpinal Cord10aspinal reflex1 aWolpaw, Jonathan1 aLee, C., L.1 aCalaitges, J., G.  uhttp://www.ncbi.nlm.nih.gov/pubmed/270735402050nas a2200181   4500008004100000022001400041245012100055210006900176260001200245300001400257490000800271520148300279653001101762653001201773100001501785700002101800856004701821       1988                        eng d  a0014-488600aJendrassik maneuver facilitates soleus H-reflex without change in average soleus motoneuron pool membrane potential.0 aJendrassik maneuver facilitates soleus Hreflex without change in  c08/1988  a288–3020 v1013 aFacilitation of spinal reflex amplitude by remote muscle contraction, otherwise known as the Jendrassik maneuver (JM), was first shown over 100 years ago, yet the mechanism by which this facilitation operates remains undetermined. Earlier work has eliminated participation of the muscle spindle in JM-induced spinal reflex facilitation, leaving changes in postsynaptic (e.g., change in average soleus motoneuron membrane potential) and presynaptic (e.g., inhibition of presynaptic inhibition) mechanisms as viable candidates. We recorded background EMG in the soleus muscle during JM-induced soleus H-reflex facilitation in humans. The JM in this experiment consisted of wrist muscle contraction. Soleus background EMG was maintained by the subject at either a zero level (e.g., relaxed) or a specified moderate level prior to and during the JM. The JM increased H-reflex amplitude by comparable amounts in both situations, but had no effect on soleus background EMG. Given the well-known relationship between the average motoneuron pool membrane potential and background EMG, we conclude that JM facilitation of the soleus H-reflex is not caused by an increase in background excitatory input to the soleus motoneuron pool. Remaining candidates for mediation of JM induced H-reflex facilitation include change in stimulus-evoked afferent input at some point proximal to the muscle spindle, such as reduction in presynaptic inhibition, or a change in motoneuron input resistance.10aReflex10aStretch1 aDowman, R.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/339664601400nas a2200253   4500008004100000022001400041245007800055210006900133260001200202300001400214490000700228520067600235653002200911653001300933653001300946653001100959653002500970653001500995653003501010653001801045100002101063700001501084856004701099       1988                        eng d  a0013-469400aOperant conditioning of primate spinal reflexes: effect on cortical SEPs.0 aOperant conditioning of primate spinal reflexes effect on cortic  c04/1988  a398–4010 v693 aPrevious studies have demonstrated operant conditioning of the primate spinal stretch reflex (SSR) and of its electrical analog, the H-reflex. We studied the evoked potential recorded over primary somatosensory cortex (SEP) which accompanies the H-reflex to determine whether the initial cortical response changes in the course of conditioned H-reflex change. When H-reflex amplitude changed, SEP amplitude also changed, but only half as much as the H-reflex. The results indicate that, while operant conditioning of the H-reflex has its largest effect on the spinal pathway of the reflex, it also has some effect on supraspinal pathways of the initial cortical response.10acortical response10aH-Reflex10aLearning10aMemory10aoperant conditioning10aplasticity10asomatosensory evoked potential10aspinal reflex1 aWolpaw, Jonathan1 aDowman, R.  uhttp://www.ncbi.nlm.nih.gov/pubmed/245073901324nas a2200229   4500008004100000022001400041245010900055210006900164260001200233300001400245490000700259520060500266653001100871653004700882653000800929653002500937653002200962100001600984700002601000700002101026856004701047       1988                        eng d  a0304-394000aRetrograde transport of the lectin Phaseolus vulgaris leucoagglutinin (PHA-L) by rat spinal motoneurons.0 aRetrograde transport of the lectin Phaseolus vulgaris leucoagglu  c03/1988  a133–1380 v863 aThe lectin Phaseolus vulgaris leucoagglutinin (PHA-L) has been used primarily as an anterograde transport tracer in the CNS. We present evidence of PHA-L retrograde transport by rat spinal motoneurons after injection into the triceps brachii. Labelled motoneurons were localized in specific and well-defined neuron pools in the ventral horn. Primary afferent labelling was not seen in the spinal gray matter. Dorsal rhizotomy did not eliminate or decrease motoneuron labelling. The retrograde transport rate was about 8 mm/day. PHA-L can clearly undergo retrograde, as well as anterograde, transport.10alectin10aphaseolus vulgaris leucoagglutinin (PHA-L)10arat10aretrograde transport10aspinal motoneuron1 aLee, C., L.1 aMcFarland, Dennis, J.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/245300201345nas a2200229   4500008004100000022001400041245011800055210006900173260001200242300001400254490000700268520062900275653001900904653001200923653002500935653003500960653001800995653001901013100002101032700001501053856004701068       1988                        eng d  a0013-469400aSpinal stretch reflex and cortical evoked potential amplitudes versus muscle stretch amplitude in the monkey arm.0 aSpinal stretch reflex and cortical evoked potential amplitudes v  c04/1988  a394–3970 v693 aWhile investigating operant conditioning of the primate spinal stretch reflex (SSR), we studied SSR amplitude and cortical somatosensory evoked potential (SEP) amplitude as stretch amplitude changed in the monkey arm. Initial muscle length and background EMG activity remained constant. With change in stretch amplitude (and proportional change in stretch velocity and acceleration), changes in SSR and SEP amplitudes were respectively 0.75 and 0.66 as great. The lesser change in SSR amplitude may reflect saturation of Ia afferents, while that in SEP amplitude may also reflect participation of other peripheral receptors.10amuscle stretch10aprimate10aSomatosensory Cortex10asomatosensory evoked potential10aspinal reflex10astretch reflex1 aWolpaw, Jonathan1 aDowman, R.  uhttp://www.ncbi.nlm.nih.gov/pubmed/245073801766nas a2200181   4500008004100000022001400041245007000055210006800125260001200193300001400205490000700219520123300226653001801459100002401477700001501501700002101516856004701537       1988                        eng d  a0378-595500aT complex hemispheric asymmetries: effects of stimulus intensity.0 aT complex hemispheric asymmetries effects of stimulus intensity  c08/1988  a225–2320 v343 aThe T complex component of the human auditory evoked potential (AEP) is thought to be produced in auditory cortex, on the posterior lateral surface of the temporal lobe. Recorded over temporal scalp, it consists of an 80-90 ms positive peak, Ta, and a 120-140 negative peak, Tb. As part of an effort to develop the clinical usefulness of the T complex in assessing auditory cortical function, we studied the effects of change in monaural stimulus intensity (20-80 dB SL) on T complex latency, amplitude, and hemispheric differences in normal adults. Ta and Tb peak latencies decreased as stimulus intensity increased. These latency changes were not dependent on ear or hemisphere. Right hemisphere Ta latency was shorter with contralateral than with ipsilateral stimulation; while left hemisphere Ta latency was not dependent on the ear stimulated. Tb latency was shorter over the left hemisphere, and over the contralateral hemisphere. Ta-b amplitude increased as stimulus intensity increased. This amplitude change was not dependent on ear or hemisphere. Ta-b amplitudes were larger over the right hemisphere and over the contralateral hemisphere. Hemispheric asymmetries were not significantly affected by stimulus intensity.10aReaction Time1 aCacace, Anthony, T.1 aDowman, R.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/317036501361nas a2200229   4500008004100000022001400041245010600055210006900161260001200230300001400242490000700256520067400263653002400937653001200961653001600973653002300989653001801012653001701030100002101047700001601068856004701084       1987                        eng d  a0014-481900aMotoneuron response to dorsal root stimulation in anesthetized monkeys after spinal cord transection.0 aMotoneuron response to dorsal root stimulation in anesthetized m  c10/1987  a428–4330 v683 aIn preparation for studying the spinal cord alterations produced by operant conditioning of spinal reflexes, we studied peripheral nerve responses to supramaximal dorsal root stimulation in the lumbosacral cord of deeply anesthetized monkeys before and after thoracic cord transection. Except for variable depression in the first few minutes, reflex responses were not reduced or otherwise significantly affected by transection in the hour immediately following the lesion or for at least 50 h. The results suggest that reduction in muscle spindle sensitivity and/or in polysynaptic motoneuron excitation contributes to stretch reflex depression after cord transection.10amonosynaptic reflex10aprimate10aSpinal Cord10aspinal cord injury10aspinal reflex10aspinal shock1 aWolpaw, Jonathan1 aLee, C., L.  uhttp://www.ncbi.nlm.nih.gov/pubmed/348023303121nas a2200157   4500008004100000022001400041245006700055210006400122260001200186300001400198490000700212520266000219653001602879100002102895856004702916       1987                        eng d  a0022-307700aOperant conditioning of primate spinal reflexes: the H-reflex.0 aOperant conditioning of primate spinal reflexes the Hreflex  c02/1987  a443–4590 v573 aThe study of primate memory substrates, the CNS alterations which preserve conditioned responses, requires an experimental model that fulfills two criteria. First, the essential alterations must be in a technically accessible location. Second, they must persist without input from other CNS regions. The spinal cord is the most technically accessible and readily isolated portion of the primate CNS. Recent work has demonstrated that the spinal stretch reflex (SSR), the initial, wholly segmental response to muscle stretch, can be operantly conditioned and suggests that this conditioning may produce persistent spinal alteration. The present study attempted similar operant conditioning of the H-reflex, the electrical analog of the SSR. The primary goals were to demonstrate that spinal reflex conditioning can occur even if the muscle spindle is removed from the reflex arc and to demonstrate conditioning in the lumbosacral cord, which is far preferable to the cervical cord for future studies of neuronal and synaptic mechanisms. Nine monkeys prepared with chronic fine-wire triceps surae (gastrocnemius and soleus) electromyographic (EMG) electrodes were taught by computer to maintain a given level of background EMG activity. At random times, a voltage pulse just above M response (direct muscle response) threshold was delivered to the posterior tibial nerve via a chronically implanted silicon nerve cuff and elicited the triceps surae H-reflex. Under the control mode, reward always followed. Under the HR increases or HR decreases mode, reward followed only if the absolute value of triceps surae EMG from 12 to 22 ms after the pulse (the H-reflex interval) was above (HR increases) or below (HR decreases) a set value. Monkeys completed 3,000-6,000 trials/day over study periods of 2-3 mo. Background EMG and M response amplitude remained stable throughout data collection. H-reflex amplitude remained stable under the control mode. Under the HR increases mode (5 animals) or HR decreases mode (4 animals), H-reflex amplitude (EMG amplitude in the H-reflex interval minus background EMG amplitude) changed appropriately over at least 6 wk. Change appeared to occur in two phases: an abrupt change within the first day, followed by slower change, which continued indefinitely. Change occurred in all three triceps surae muscles (medial and lateral gastrocnemii and soleus). Under the HR increases mode, H-reflex amplitude rose to an average of 213% of control, whereas under the HR decreases mode it fell to an average of 68% of control. The results demonstrate that the H-reflex can be operantly conditioned.(ABSTRACT TRUNCATED AT 400 WORDS)10aSpinal Cord1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/355968702150nas a2200193   4500008004100000022001400041245007100055210006900126260001200195300001400207490000700221520158500228653001601813100002101829700002001850700001901870700002001889856004701909       1986                        eng d  a0022-307700aAdaptive plasticity in primate spinal stretch reflex: persistence.0 aAdaptive plasticity in primate spinal stretch reflex persistence  c02/1986  a272–2790 v553 aMonkeys can gradually change the amplitude of the wholly segmental, largely monosynaptic, spinal stretch reflex (SSR) when confronted by a task requiring such change (15-19). Change develops over months and may reverse and redevelop at similarly slow rates. We investigated the persistence of SSR amplitude change over nonperformance periods of up to 38 days. Eight animals with chronic EMG electrodes learned to maintain elbow angle and a given level of biceps background EMG against constant extension torque. At random times, a brief additional extension torque pulse elicited the biceps SSR. In the control mode, reward always followed. Under the SSR increase or SSR decrease mode, reward occurred only if the absolute value of biceps EMG in the SSR interval was above or below a set value. Animals completed 3,000-6,000 trials/day over data-collection periods of 2-17 mo. Animals worked first under the control mode for up to 60 days and then under the SSR increase or SSR decrease mode for up to 274 days. Mode was switched once or twice more (SSR increase to SSR decrease or vice versa) over subsequent months. Animals responded to each SSR increase or SSR decrease mode exposure with gradual mode-appropriate change in SSR amplitude. Mode exposures were interrupted by gaps in performance of 10-38 days. Gaps produced transient 10- to 15% decreases in SSR amplitude under the control mode. This nonspecific decrease disappeared over the first week of postgap performance. Under the control mode, gaps had no other effects on SSR amplitude.(ABSTRACT TRUNCATED AT 250 WORDS)10aSpinal Cord1 aWolpaw, Jonathan1 aO'Keefe, J., A.1 aNoonan, P., A.1 aSanders, M., G.  uhttp://www.ncbi.nlm.nih.gov/pubmed/395069101726nas a2200217   4500008004100000022001400041245009000055210006900145260001200214300001400226490000600240520110600246653001301352653001101365653001501376653001201391653001801403653001901421100002101440856004701461       1985                        eng d  a0272-434000aAdaptive plasticity in the spinal stretch reflex: an accessible substrate of memory?.0 aAdaptive plasticity in the spinal stretch reflex an accessible s  c06/1985  a147–1650 v53 aThe study of the substrates of memory in higher vertebrates is one of the major problems of neurobiology. A simple and technically accessible experimental model is needed. Recent studies have demonstrated long-term adaptive plasticity, a form of memory, in the spinal stretch reflex (SSR). The SSR is due largely to a two-neuron monosynaptic arc, the simplest, best-defined, and most accessible pathway in the primate central nervous system (CNS). Monkeys can slowly change SSR amplitude without a change in initial muscle length or alpha motoneuron tone, when reward is made contingent on amplitude. Change occurs over weeks and months and persists for long periods. It is relatively specific to the agonist muscle and affects movement. The salient features of SSR adaptive plasticity, combined with clinical and laboratory evidence indicating spinal cord capacity for intrinsic change, suggest that SSR change eventually involves persistent segmental alteration. If this is the case, SSR plasticity should be a powerful model for studying the neuronal and synaptic substrates of memory in a primate.10aLearning10aMemory10aplasticity10aprimate10aspinal reflex10astretch reflex1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/316161601147nas a2200253   4500008004100000022001400041245010300055210006900158260001200227300001400239490000700253520041700260653001300677653001100690653001500701653001200716653001800728653001900746100002100765700002000786700002000806700002000826856004700846       1985                        eng d  a0304-394000aReduced day-to-day variation accompanies adaptive plasticity in the primate spinal stretch reflex.0 aReduced daytoday variation accompanies adaptive plasticity in th  c03/1985  a165–1710 v543 aMonkeys can change the amplitude of the spinal stretch reflex (SSR), or M1, when reward is made contingent on amplitude. The present study demonstrates that reduced SSR day-to-day variation accompanies such adaptive SSR change. This finding supports the assumption that initial, phase I, SSR change results from contingency-appropriate stabilization of tonic activity in relevant descending spinal cord pathways.10aLearning10aMemory10aplasticity10aprimate10aspinal reflex10astretch reflex1 aWolpaw, Jonathan1 aO'Keefe, J., A.1 aKieffer, V., A.1 aSanders, M., G.  uhttp://www.ncbi.nlm.nih.gov/pubmed/399105702097nas a2200241   4500008004100000022001400041245010700055210006900162260001200231300001400243490000800257520138500265653002401650653001901674653001301693653001101706653001201717653001901729100002101748700001901769700002001788856004701808       1984                        eng d  a0006-899300aAdaptive plasticity and diurnal rhythm in the primate spinal stretch reflex are independent phenomena.0 aAdaptive plasticity and diurnal rhythm in the primate spinal str  c05/1984  a385–3910 v3003 aRecent studies have revealed two phenomena producing considerable variation in amplitude of the initial, purely segmental, largely monosynaptic, response to sudden muscle stretch, the spinal stretch reflex (SSR), without change in background EMG activity or initial muscle length. The first is small and short-term, a modest diurnal rhythm in SSR amplitude. The second is large and long-term, marked adaptive change in SSR amplitude which occurs gradually over weeks and months when animals are rewarded for such change. This second phenomenon may involve persistent segmental alteration, and, if so, could constitute a technically accessible substrate of memory. The present study compared the two phenomena and sought evidence of interaction between them. The diurnal rhythm persisted, without change in phase and with only minimal change in amplitude, despite the occurrence of marked adaptive change. Animals did not utilize the rhythm to increase reward percentage by altering daily performance schedules. These results suggest that the mechanisms of the diurnal rhythm and of adaptive plasticity in SSR amplitude are separate and independent. The diurnal rhythm's effect on movement was not altered by adaptive change in SSR amplitude. This effect was comparable to adaptive change's effect on movement when both were expressed as change in movement/change in SSR amplitude.10aadaptive plasticity10adiurnal rhythm10aLearning10aMemory10aprimate10astretch reflex1 aWolpaw, Jonathan1 aNoonan, P., A.1 aO'Keefe, J., A.  uhttp://www.ncbi.nlm.nih.gov/pubmed/653963402101nas a2200169   4500008004100000022001400041245009600055210006900151260001200220300001600232490000600248520157200254653001701826100002101843700002001864856004701884       1984                        eng d  a0270-647400aAdaptive plasticity in the primate spinal stretch reflex: evidence for a two-phase process.0 aAdaptive plasticity in the primate spinal stretch reflex evidenc  c11/1984  a2718–27240 v43 aMonkeys can slowly increase or decrease the amplitude of the purely spinal, largely monosynaptic portion of the response to sudden muscle stretch, the spinal stretch reflex (SSR), when confronted by a task requiring such change (Wolpaw, J.R., V.A. Kieffer, R.F. Seegal, D.J. Braitman, and M.G. Sanders (1983) Brain Res. 267: 196-200; Wolpaw, J.R., D.J. Braitman, and R.F. Seegal (1983) J. Neurophysiol. 50: 1296-1311). Change occurs without alteration in initial muscle length or in background activity of agonist, antagonist, or synergist muscles. This study uses composite curves to describe in detail the development of SSR amplitude change. It reveals important, previously unexpected features of this development. SSR increase or decrease appears to occur in two distinct phases. Phase I, a nearly immediate 8% change, occurs within the first 6 hr. Phase II, a 2%/day change, continues for at least 2 months. Although phase II is much slower than phase I, its final magnitude is far greater. Phase I indicates a nearly immediate change in suprasegmental influence of the segmental arc of the SSR. Because stretch onset time is unpredictable and the SSR occurs before any other possible response, this change in descending activity must be tonic; it must be present continually, day after day, for the 5 to 7 hr/day the animal spends at the task. Phase I produces a rapid and significant increase in reward probability. Thus, it may be readily interpreted as an example of operant conditioning, provoked by the reward contingency.(ABSTRACT TRUNCATED AT 250 WORDS)10aTime Factors1 aWolpaw, Jonathan1 aO'Keefe, J., A.  uhttp://www.ncbi.nlm.nih.gov/pubmed/650220001987nas a2200205   4500008004100000022001400041245008200055210006900137260001200206300001200218490000600230520135500236653003701591100002401628700002201652700001901674700002001693700002101713856004701734       1984                        eng d  a0196-070900aPsychoacoustic and electrophysiologic effects of partial eighth nerve damage.0 aPsychoacoustic and electrophysiologic effects of partial eighth   c02/1984  a43–480 v53 aThe authors present psychoacoustic and electrophysiologic data concerning a patient with partial damage to the auditory nerve, presumably from a dilated arterial vessel. The lesion was described and documented during neurosurgery for vestibular nerve decompression. Pure tone thresholds, psychoacoustical tuning curves, speech reception ability for spondaic words, maximum word recognition performance for monosyllabic NU-6 word lists, and performance on the synthetic sentence identification test in the ipsilateral and contralateral competing message modalities were normal. Findings consistent with eighth nerve dysfunction, absent contralateral acoustic reflexes, absent or unrecognizable early evoked potentials occurring in the first 10 msec, brainstem auditory evoked potentials (BAEPs), and slight rollover of the performance intensity function for monosyllabic words were obtained on the involved side. In spite of the grossly abnormal BAEPs, two late, presumably cortical, auditory evoked potential components, which occur in the 60 to 250-msec range–vertex potential and T complex–were present and normal. The findings indicate that the perceptual processes needed for speech reception and recognition and for the appearance of later, presumably cortical-evoked potentials can be preserved despite partial damage to the auditory nerve.10aVestibulocochlear Nerve Diseases1 aCacace, Anthony, T.1 aGoldstein, J., C.1 aParnes, S., M.1 aSatya-Murti, S.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/653419301682nas a2200181   4500008004100000022001400041245010400055210006900159260001200228300001600240490000700256520111400263653001601377100002101393700001901414700002001433856004701453       1983                        eng d  a0022-307700aAdaptive plasticity in primate spinal stretch reflex: behavior of synergist and antagonist muscles.0 aAdaptive plasticity in primate spinal stretch reflex behavior of  c12/1983  a1312–13190 v503 aMonkeys can gradually change the amplitude of the biceps spinal stretch reflex (SSR) without change in initial muscle length or biceps background electromyographic activity (EMG) (17). We investigated the concurrent behavior of synergist (brachialis and brachioradialis) and antagonist (triceps) muscles. Synergist background EMG remained stable while marked change occurred in biceps SSR amplitude. Triceps background EMG was minimal under all conditions. Thus biceps SSR amplitude change was not due to change in the background activity of closely related muscles. When biceps SSR amplitude changed, synergist SSR amplitude changed similarly but to a lesser extent. Brachialis change averaged 72% of biceps change, while brachioradialis change averaged 33%. By indicating that SSR amplitude change is relatively specific to the agonist muscle, this finding eliminates a number of nonspecific mechanisms as possible origins of SSR amplitude change. Thus it supports the potential value of the SSR as a system for studying the neuronal and synaptic bases of memory in the primate central nervous system (CNS).10aSpinal Cord1 aWolpaw, Jonathan1 aSeegal, R., F.1 aO'Keefe, J., A.  uhttp://www.ncbi.nlm.nih.gov/pubmed/666332802956nas a2200181   4500008004100000022001400041245007900055210006900134260001200203300001600215490000700231520241200238653001602650100002102666700002102687700001902708856004702727       1983                        eng d  a0022-307700aAdaptive plasticity in primate spinal stretch reflex: initial development.0 aAdaptive plasticity in primate spinal stretch reflex initial dev  c12/1983  a1296–13110 v503 aDescription of the neuronal and synaptic bases of memory in the vertebrate central nervous system (CNS) requires a CNS stimulus-response pathway that is defined and accessible, has the capacity for adaptive change, and clearly contains the responsible substrates. This study was an attempt to determine whether the spinal stretch reflex (SSR), the initial, purely spinal, portion of the muscle stretch response, which satisfies the first requirement, also satisfies the second, capacity for adaptive change. Monkeys prepared with chronic fine-wire biceps electromyographic (EMG) electrodes were trained to maintain elbow position and a given level of biceps background EMG activity against constant extension torque. At random times, a brief additional extension torque pulse extended the elbow and elicited the biceps SSR. Under the control mode, reward always followed. Under the SSR increases or SSR decreases mode, reward followed only if the absolute value of biceps EMG from 14 to 24 ms after stretch onset (the SSR interval) was above or below a set value. Animals performed 3,000-6,000 trials/day over data-collection periods of up to 15 mo. Background EMG and the initial 30 ms of pulse-induced extension remained stable throughout data collection. Under the SSR increases or SSR decreases mode, SSR amplitude (EMG amplitude in the SSR interval minus background EMG amplitude) changed appropriately. Change was evident in 5-10 days and progressed over at least 4 wk. The SSR increased (SSR increases) to 140-190% control amplitude or decreased (SSR decreases) to 22-79%. SSR change did not regress over 12-day gaps in task performance. A second pair of biceps electrodes, monitored simultaneously, supplied comparable data, indicating that SSR amplitude change occurred throughout the muscle. Beyond 40 ms after pulse onset, elbow extension was inversely correlated with SSR amplitude. The delay between the SSR and its apparent effect on movement is consistent with expected motor-unit contraction time. The data demonstrate that the SSR is capable of adaptive change. At present the most likely site(s) of the mechanism of SSR amplitude change are the Ia synapse and/or the muscle spindle. Available related evidence suggests persistent segmental change may in fact come to mediate SSR amplitude change. If so, such segmental change would constitute a technically accessible fragment of a memory.10aSpinal Cord1 aWolpaw, Jonathan1 aBraitman, D., J.1 aSeegal, R., F.  uhttp://www.ncbi.nlm.nih.gov/pubmed/666332701504nas a2200217   4500008004100000022001400041245009100055210006900146260001200215300001400227490000800241520088100249653001301130653001101143653001501154653001201169653001801181653001901199100002101218856004701239       1983                        eng d  a0006-899300aAdaptive plasticity in the primate spinal stretch reflex: reversal and re-development.0 aAdaptive plasticity in the primate spinal stretch reflex reversa  c11/1983  a299–3040 v2783 aMonkeys can gradually increase or decrease the amplitude of the segmentally mediated spinal stretch reflex (SSR) without change in initial muscle length or background EMG activity. Both increase (under the SSR increases mode) and decrease (under the SSR decreases mode) occur slowly, progressing steadily over weeks. The present study investigated reversal and re-development of SSR amplitude change. Over a period of months, following collection of control data, monkeys were exposed to one mode, then to the other, and then to the first mode again. Development, reversal, and re-development of change all took place over weeks, following very similar courses. These data are consistent with the hypothesis that persistent segmental alteration underlies SSR amplitude change. Such persistent segmental alteration would constitute a technically accessible substrate of memory.10aLearning10aMemory10aplasticity10aprimate10aspinal reflex10astretch reflex1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/664032001114nas a2200265   4500008004100000022001400041245005400055210005300109260001200162300001400174490000800188520041600196653001300612653001100625653001500636653001200651653001800663653001900681100002100700700002000721700001900741700002100760700002000781856004700801       1983                        eng d  a0006-899300aAdaptive plasticity in the spinal stretch reflex.0 aAdaptive plasticity in the spinal stretch reflex  c05/1983  a196–2000 v2673 aMonkeys can change the amplitude of the spinal stretch reflex without change in initial alpha motor neuron tone, as measured by EMG, or in initial muscle length. Change is apparent in 5-10 days, continues to develop over weeks, and persists during inactive periods. Spinal stretch reflex change may be a valuable system for studying the neuronal and synaptic bases of an adaptive change in primate CNS function.10aLearning10aMemory10aplasticity10aprimate10aspinal reflex10astretch reflex1 aWolpaw, Jonathan1 aKieffer, V., A.1 aSeegal, R., F.1 aBraitman, D., J.1 aSanders, M., G.  uhttp://www.ncbi.nlm.nih.gov/pubmed/686094801136nas a2200193   4500008004100000022001400041245007700055210006900132260001200201300001400213490000700227520056400234653001100798100002000809700002100829700002400850700002100874856004700895       1983                        eng d  a0013-469400aLate auditory evoked potentials can occur without brain stem potentials.0 aLate auditory evoked potentials can occur without brain stem pot  c10/1983  a304–3080 v563 aThe sequence of early, middle and late auditory evoked potentials is well known. However, it is unknown whether the late (60-250 msec) potentials can occur independently of the early, brain stem potentials. Therefore, in 6 subjects with markedly abnormal or absent brain stem potentials, we recorded two of the late potentials: the vertex potential and the T-complex. The latter is a putative product of auditory cortex. Both of these potentials were clearly evident in all patients in spite of the absence of or marked abnormalities in brain stem potentials.10aHumans1 aSatya-Murti, S.1 aWolpaw, Jonathan1 aCacace, Anthony, T.1 aSchaffer, C., A.  uhttp://www.ncbi.nlm.nih.gov/pubmed/619394301683nas a2200169   4500008004100000022001400041245007100055210006900126260001200195300001600207490000700223520119200230653001101422653001201433100002101445856004701466       1982                        eng d  a0014-944600aChange in short-latency response to limb displacement in primates.0 aChange in shortlatency response to limb displacement in primates  c04/1982  a2156–21590 v413 aWhen a muscle is stretched in an awake, behaving primate the earliest electromyographic (EMG) responses of the muscle consists of several reflex components. The earliest, M1, is mediated entirely at the segmental level and is largely monosynaptic. The next M2, is at least in part the result of an oligosynaptic transcortical loop to control the M1 response remains to be established. If primates can learn to control M1 amplitude, the M1 loop, which is the simplest and most accessible stimulus-response pathway in the primate central nervous system, may serve as a model for the study of mechanisms of memory. Preliminary evidence presented here strongly suggests that primates can control M1 gain without change in prestimulus EMG activity. The mechanisms of such change remain to be determined. Possibilities include change in gamma motor neuron tone, in Ia synaptic function, and in alpha motor neuron recruitment. The usefulness of learned M1 change as a model for memory will depend to a large extent on the nature of the responsible mechanism and on demonstration that the change can eventually become resident at the segmental level, without need for continued descending input.10aReflex10aStretch1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/707578901145nas a2200229   4500008004100000022001400041245004900055210004800104260001200152300001400164490000800178520053400186653002100720653001900741653001900760653001200779653001800791653001900809100002100828700001900849856004700868       1982                        eng d  a0006-899300aDiurnal rhythm in the spinal stretch reflex.0 aDiurnal rhythm in the spinal stretch reflex  c07/1982  a365–3690 v2443 aWe studied primate spinal stretch reflex (SSR) amplitude as a function of time of day. SSR amplitude was greatest around midnight and smallest around noon. The diurnal rhythm was not simply a function of number of trials, or of the lighting cycle. This rhythm offers an opportunity to study the neuronal and synaptic mechanisms producing a diurnal change in CNS function. Its existence indicates that the CNS response to a given limb disturbance, and thus the CNS activity underlying a given performance, varies with time of day.10acircadian rhythm10adiurnal rhythm10amuscle stretch10aprimate10aspinal reflex10astretch reflex1 aWolpaw, Jonathan1 aSeegal, R., F.  uhttp://www.ncbi.nlm.nih.gov/pubmed/688945202362nas a2200169   4500008004100000022001400041245010400055210006900159260001200228300001200240490000700252520183600259653001202095100002102107700001702128856004702145       1982                        eng d  a0013-469400aScalp distribution of human auditory evoked potentials. I. Evaluation of reference electrode sites.0 aScalp distribution of human auditory evoked potentials I Evaluat  c07/1982  a15–240 v543 aIn an attempt to settle the long-standing controversy about the relative activity of nose, sternovertebral (SV), and other commonly used AEP reference sites, we recorded AEPs from a coronal chain of electrodes from the vertex to the tragus, extending down the neck, and from the nose, ear, mastoid process, knee and ankle. All electrodes were referred to a sternovertebral reference balanced to minimize EKG. Voltage gradients and wave forms corresponding to other references were derived by computer. Stimuli were presented at fixed durations after the R wave of the EKG and averages with no stimulus were subtracted from averages with click stimuli to minimize synchronized EKG activity in non-cephalic derivations.

Because the activity at a given electrode site cannot be determined in absolute terms, alternative reference sites must be compard by examining the relative location of each site in the total potential field. An indifferent electrode site defined in this manner is one at which the spatial and temporal voltage gradients are minimal over the duration of the activity of interest. AEP voltage gradients in this experiment were steepest in the temporal region, became extremely shallow at locations on the upper neck, and showed no detectable gradients below that point attributable to AEP activity. A gradient of this form was obtained in all subjects, in spite of significant intersubject differences in the magnitude of potentials in nose-SV derivations. Commonly used reference sites on the head such as the nose, ear and mastoid process, were shown to lie in regions of the AEP field characterized by significant voltage gradients over time and spatial location in most subjects. The balanced sternovertebral reference of Stephenson and Gibbs (1951) appears to be the best general choice for AEP recordings.10aSternum1 aWolpaw, Jonathan1 aWood, C., C.  uhttp://www.ncbi.nlm.nih.gov/pubmed/617751401880nas a2200169   4500008004100000022001400041245013300055210006900188260001200257300001200269490000700281520131900288653001801607100001701625700002101642856004701663       1982                        eng d  a0013-469400aScalp distribution of human auditory evoked potentials. II. Evidence for overlapping sources and involvement of auditory cortex.0 aScalp distribution of human auditory evoked potentials II Eviden  c07/1982  a25–380 v543 aThe scalp distributions of human auditory evoked potentials (AEPs) between 20 and 250 msec were investigated using non-cephalic reference recordings. AEPs to binaural click stimuli were recorded simultaneously from 20 scalp locations over the right hemisphere in 11 subjects. Computer-generated isovoltage topographic maps at high temporal resolution were used to assess the stability of AEP scalp distributions over time and relate them to major peaks in the AEP wave forms. For potentials between 20 and 60 msec, the results demonstrate a stable scalp distribution of dipolar form that is consistent with sources in primary auditory cortex on the superior temporal plant near the temporoparietal junction. For potentials between 60 and 250 msec, the results demonstrate changes in AEP morphology across electrode locations and changes in scalp distribution over time that lead to two major conclusions. First, AEPs in this latency period are generated by multiple sources which partially overlap in time. Second, one or more regions of auditory cortex contribute significantly to AEPs in this period. Additional data are needed to determine the relative contribution of auditory cortex sources on the superior temporal plane and the lateral temporal surface and to identify AEP sources outside the temporal lobe.10aTemporal Lobe1 aWood, C., C.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/617751502202nas a2200157   4500008004100000022001400041245009700055210006900152260001200221300001600233490000700249520171000256653001001966100002101976856004701997       1980                        eng d  a0022-307700aAmplitude of responses to perturbation in primate sensorimotor cortex as a function of task.0 aAmplitude of responses to perturbation in primate sensorimotor c  c12/1980  a1139–11470 v443 a1. Monkeys learned to maintain hand position against a range of background forces. Short-latency responses to passive wrist extension or flexion were recorded from units in areas 4, 3, 1, and 2. Response amplitude was studied as a function of background force direction (extension or flexion). 2. For 40% of the precentral and postcentral responses, response amplitude depended on constant force direction. For these dependent responses, amplitude with background force in one direction averaged 2.8 times amplitude with background force in the opposite direction. 3. Units for which background activity varied with constant force direction were designated task related. Dependent responses from area 4 task-related units were usually larger when background activity was greater and when background force direction matched the direction of the passive movement. 4. Dependent responses from area 4 task-related units occurred significantly later than nondependent responses from the same units. 5. Since most area 4 task-related activity was explicable as a result of peripheral input via the same oligosynaptic path mediating area 4 responses to passive movements (32), the present findings imply that area 4-task-related activity may result in large part from centrally mediated change in the access of short-latency peripheral input to area 4 units. 6. The dependence of responses from non-task-related area 4 units and from non-task-related and task-related postcentral units showed no dominant correlation with background activity or with background force direction. Their dependence appeared to require no explanation other than a change in peripheral input with change in background force direction.10aWrist1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/745232502972nas a2200157   4500008004100000022001400041245010900055210006900164260001200233300001600245490000700261520244400268653003402712100002102746856004702767       1980                        eng d  a0022-307700aCorrelations between task-related activity and responses to perturbation in primate sensorimotor cortex.0 aCorrelations between taskrelated activity and responses to pertu  c12/1980  a1122–11380 v443 a1. Monkeys were trained to maintain hand position against a range of constant forces. Short-latency responses to passive wrist extension or flexion, as well as short-latency responses to stretch of a single wrist muscle, were recorded from units in areas 4, 3, 1, and 2. These responses were compared to unit activity during active holding and during active movement. 2. Units related to active holding and to active movement were most common in areas 4 and 2. Three-quarters of these units displayed a specific correlation between their passive and active behaviors. Thus, a unit excited by passive extension was excited during active holding against extension force and excited during an active flexion movement. This behavior is similar to the expected concurrent behavior of muscle stretch receptors. By demonstrating that a significant number of task-related units give qualitatively similar responses to passive extension and passive flexion, the results appear to explain the disagreement among previous studies (5, 9, 36) in regard to area 4 behavior during active and passive movements. 3. Area 4 units responded similarly to passive wrist extension and electromagnetic stretch of a single flexor muscle occurring in the absence of wrist extension, indicating that muscle stretch was important in determining area 4 unit responses to passive movements. 4. The similarity of area 4 behavior to area 2 behavior in active and passive situations, along with the observation that area 2 responses to passive movements occurred several milliseconds earlier than those of area 4, emphasizes the importance of area 2 in motor performance and is consistent with significant area 2 mediation of area 4 responses. 5. Results support the hypothesis of an oligosynaptic transcortical pathway (22, 32, 34), beginning in large part with muscle stretch receptors. Furthermore, the correlation noted between short-latency responses to passive movement and task-related activity suggests that this transcortical pathway not only mediates responses to passive movement but may be responsible, to a significant degree, for task-related activity during undisturbed performance. Thus, active position maintenance and active movement were probably accomplished, at least in part, by increasing and decreasing the influence of this pathway on specific area 4 neurons and thereby producing the patterns of area 4 activity responsible for task performance.10aTask Performance and Analysis1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/645027501552nas a2200253   4500008004100000022001400041245007000055210006900125260001200194300001400206490000700220520079000227653002601017653003601043653001801079653002301097653002401120653002701144100002001171700001501191700002401206700002101230856004701251       1980                        eng d  a0140-011800aElectromagnetic method for in situ stretch of individual muscles.0 aElectromagnetic method for in situ stretch of individual muscles  c03/1980  a145–1520 v183 aA technique for stretching individual muscles in intact behaving animals via chronic intramuscular implantation of a permeable slug and use of an external electromagnet to apply force to the slug has been developed for use in the study of the role of sensory input due to muscle stretch in the control of skilled motor activity. This paper is an analysis of the force exerted on a permeable slug by a solenoid, and a discussion of practical aspects of design and control. The force exerted on a slug inside a coil is a function of slug length, cross-sectional area, and magnetisation properties and of coil size, geometry, and current. The force inside the coil may be increased by surrounding the coil with a permeable sleeve and thereby increasing the field strength inside the coil.10aElectromagnetic force10aElectromagnetic muscle strength10aMotor control10aMuscle stimulation10aSensorimotor system10aStimulation with force1 aColburn, T., R.1 aVaughn, W.1 aChristensen, J., L.1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/677147300912nas a2200157   4500008004100000022001400041245010200055210006900157260001200226300001400238490000800252520040800260653001900668100002100687856004600708       1979                        eng d  a0036-807500aElectromagnetic muscle stretch strongly excites sensorimotor cortex neurons in behaving primates.0 aElectromagnetic muscle stretch strongly excites sensorimotor cor  c02/1979  a465–4670 v2033 aResponses of single units in primary motor and sensory cortex of behaving primates to electromagnetic stretch of the muscle flexor carpi ulnaris are comparable in latency and intensity to responses to wrist extension. Thus, muscle stretch appears to be a major factor in cortical response to limb displacement during performance and probably has an important role in motor control at the cortical level.10aProprioception1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/10438500488nas a2200145   4500008004100000022001400041245010700055210006900162260001200231300001400243490000800257653001000265100002100275856004600296       1979                        eng d  a0006-899300aGyral impressions in the skull as a guide to cortical topography in chronic transdural unit recording.0 aGyral impressions in the skull as a guide to cortical topography  c01/1979  a505–5080 v16010aSkull1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/10578101222nas a2200157   4500008004100000022001400041245011400055210006900169260001200238300001400250490000700264520070900271653001800980100002100998856004501019       1979                        eng d  a0013-469400aSingle unit activity vs. amplitude of the epidural evoked potential in primary auditory cortex of awake cats.0 aSingle unit activity vs amplitude of the epidural evoked potenti  c09/1979  a372–3760 v473 aThe study investigated, in primary auditory cortex (AI) of awake cats, the relationship over a range of stimuli between the amplitude and latency of the initial positive deflection (P1) of the primary evoked potential and the intensity of concurrent underlying evoked single unit activity. Epidural evoked potentials and extracellular responses of 155 single units to monaural 100 musec clicks ranging from 45 to 110 dB were recorded. At low stimulus levels, considerable unit response could occur with a very small P1. At middle stimulus levels, unit response was directly proportional to P1 amplitude. At higher stimulus levels, P1 amplitude continued to increase while unit response began to saturate.10aReaction Time1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/9060702319nas a2200205   4500008004100000022001400041245010200055210006900157260001200226300001300238490000700251520166900258653003101927653002901958653002701987653001402014100002102028700001802049856004602067       1978                        eng d  a0013-958000aAcute and chronic antiepileptic drug effect on the T complex interhemispheric latency difference.0 aAcute and chronic antiepileptic drug effect on the T complex int  c02/1978  a99–1070 v193 aAntiepileptic drugs may significantly affect brain function in the absence of overt toxicity or excessive serum drug levels. A clinically practical monitor of such effects would be of considerable value in clinical research and practice.

Auditory evoked responses were recorded from patients before and after initiation of antiepileptic drug therapy and from patients on therapy for at least 1 year. T complexes were isolated (Wolpaw and Penry, 1975), and Ta peak ipsilateral versus contralateral latency differences were determined.

In 13 patients beginning phenobarbital, more than half the postdrug determinations were significantly increased over the patients' predrug control values in the first 30 days and thereafter, and grossly abnormal values were frequent. In 10 patients beginning phenytoin, latency differences were similarly increased, although grossly abnormal values were less common. In 2 patients beginning clonazepam, 14 of 15 postdrug determinations were significantly increased, and five were grossly abnormal. In no patients were serum drug levels above the therapeutic ranges. In 40 patients chronically treated with phenobarbital or primidone, phenytoin, or a combination of phenytoin and phenobarbital or primidone, abnormal latency differences were obtained in 33, 36, and 29% of the determinations, respectively.

The Ta peak ipsilateral versus contralateral latency difference is an internally controlled correlate of higher level specific sensory function which is sensitive to acute and chronic therapy with phenobarbital, phenytoin, or clonazepam in therapeutic dosages. With further investigation, it may be of clinical use.10aAntiepileptic drug effects10aAuditory evoked response10aHemispheric difference10aT complex1 aWolpaw, Jonathan1 aPenry, J., K.  uhttp://www.ncbi.nlm.nih.gov/pubmed/62427201639nas a2200169   4500008004100000022001400041245007900055210006900134260001200203300001400215490000700229520113600236653001301372100002101385700001801406856004501424       1978                        eng d  a0013-469400aEffects of ethanol, caffeine, and placebo on the auditory evoked response.0 aEffects of ethanol caffeine and placebo on the auditory evoked r  c05/1978  a568–5740 v443 aA previous paper (Wolpaw and Penry 1975) described separation of the 75-250 msec portion of the AER into N1P2, a product of large areas of cortex, and the T complex, probably a product of secondary auditory cortex. With monaural stimulation, the T complex is larger and earlier on the side contralateral to stimulation and on the right side. Thirty-one normal adults received 3 oz. of ethanol, 300 mg of caffeine, or placebo. Monaural AERs were recorded before intake in all cases, 1 and 4 h after ethanol and 80 min after caffeine or placebo. Blood levels of ethanol and caffeine were measured. Placebo produced mild (20%) decreases in N1P2 amplitude. Caffeine did not decrease N1P2 amplitude. It did produce a statistically significant 2% decrease in Ta peak latency. Ethanol reduced N1P2 amplitude markedly at 1 h and mildly at 4 h. Placebo did not affect hemispheric differences. Caffeine significantly increased the Ta peak ipsilateral vs. contralateral latency difference in 3 of 7 individuals. Ethanol significantly increased it in 3 of 6 subjects at 1 h and in 7 of 10 at 4 h, primarily by increasing ipsilateral latencies.10aPlacebos1 aWolpaw, Jonathan1 aPenry, J., K.  uhttp://www.ncbi.nlm.nih.gov/pubmed/7776300491nas a2200157   4500008004100000022001400041245007200055210006900127260001200196300001400208490000800222653001600230100002100246700002000267856004600287       1978                        eng d  a0006-899300aElectromagnetic stretch of individual muscles in behaving primates.0 aElectromagnetic stretch of individual muscles in behaving primat  c02/1978  a193–1960 v14110aWakefulness1 aWolpaw, Jonathan1 aColburn, T., R.  uhttp://www.ncbi.nlm.nih.gov/pubmed/41482301828nas a2200169   4500008004100000022001400041245006100055210006000116260001200176300001300188490000700201520134800208653001801556100002101574700001801595856004501613       1977                        eng d  a0013-469400aHemispheric differences in the auditory evoked response.0 aHemispheric differences in the auditory evoked response  c07/1977  a99–1020 v433 aThe separation of the 80-250 msec portion of the AER to click stimulation into N1P2, produced by large areas of cortex, and the T complex, probably produced by secondary auditory cortex, was recently described (Wolpaw and Penry 1975). The present study investigated the ipsilateral vs. contralateral and right vs. left hemispheric differences in N1P2 and T complex latencies and amplitudes. One msec clicks at 60 dB above threshold were presented at 4.7 sec intervals monaurally to 32 normal adults and binaurally to 13 of the 32. AERs were recorded from vertex and temporal referred to a balanced non-cephalic reference electrode. For monaural stimulation, N1P2 and T complex amplitudes were significantly greater and T complex latency was significantly less over the contralateral and right hemispheres. The ipsilateral vs. contralateral and right vs. left hemispheric amplitude differences were significanlty greater for the T complex than for N1P2. Binaural results, which provided in additional measure of right vs. left hemispheric differences, were in agreement with the monaural findings. The results are consistent with neurophysiologic and behavioral findings in regard to ipsilateral vs. contralateral and right vs. left hemispheric differences and support the hypothesis that the T complex is produced by secondary auditory cortex.10aReaction Time1 aWolpaw, Jonathan1 aPenry, J., K.  uhttp://www.ncbi.nlm.nih.gov/pubmed/6887802233nas a2200169   4500008004100000022001400041245005800055210005500113260001200168300001400180490000700194520176100201653001701962100002101979700001802000856004502018       1975                        eng d  a0013-469400aA temporal component of the auditory evoked response.0 atemporal component of the auditory evoked response  c12/1975  a609–6200 v393 aWe studied the 75-225 msec portion of the auditory evoked response (AER) in 32 normal adults at vertex (Cz) and temporal (T3 and T4) placements referred to a balanced, noncephalic reference electrode using a monaural 1 msec click stimulus delivered every 4.7 sec at 60 dB above threshold. The tape-recorded EEG was filtered at 1-25 c/sec, and 128 individual responses were summed, sampling every 0.5 msec for 250 msec post-stimulation. The Cz AERs showed the classic vertex response, a negative peak, N1, at 100 msec, followed by a positive peak, P2, at 160-200 msec. The T3 and T4 AERs were similar to the Cz AERs from 0 to 80 msec and from 200 to 250 msec. They differed significantly from the Cz AERs from 80 to 200 msec. The difference is best explained by the hypothesis that the Cz AERs consisted of N1P2, while the T3 and T4 AERs consisted of N1P2 plus an additional superimposed component, which we called the T complex, comprising a positive peak, Ta, at 105-110 msec, and a negative peak, Tb, at 150-160 msec. By computer, the corresponding Cz and T3 or T4 AERs were normalized to equalize their amplitudes, and the former was subtracted from the latter, thus isolating the T complex. The Ta peak was found to occur 1.5 +/- 1.6 msec earlier at the electrode contralateral to stimulation, and 2.2 +/- 4.0 msec earlier at the T4 (right) electrode. Both differences were statistically significant. The T complex amplitude was greater at the electrode contralateral to stimulation and at the T4 electrode. These findings appear to resolve current controversies concerning the form of the temporal AER. While N1P2 is apparently a product of widespread areas of cortex, we conclude that the T complex is probably a product of secondary auditory cortex.10aTime Factors1 aWolpaw, Jonathan1 aPenry, J., K.  uhttp://www.ncbi.nlm.nih.gov/pubmed/5313900885nas a2200181   4500008004100000022001400041245006800055210006700123260001200190300001400202490000800216520035200224653002000576100002100596700002000617700001900637856004700656       1973                        eng d  a0098-748400aTongue necrosis attributed to ergotamine in temporal arteritis.0 aTongue necrosis attributed to ergotamine in temporal arteritis  c07/1973  a514–5150 v2253 aOn two occasions, a woman with temporal arteritis developed tongue cyanosis and numbness shortly after the administration of ergotamine tartrate. Partial necrosis of the tongue resulted. Presumably, the lingual artery compromise, frequently present in temporal arteritis, was made symptomatic by the vasoconstrictive action of ergotamine tartrate.10aTongue Diseases1 aWolpaw, Jonathan1 aBrottem, J., L.1 aMartin, H., L.  uhttp://www.ncbi.nlm.nih.gov/pubmed/474034000392nas a2200145   4500008004100000022001400041245003700055210003600092260001200128300000800140490000600148653002400154100002100178856004700199       1971                        eng d  a0140-673600aAetiology of retrograde amnesia.0 aAetiology of retrograde amnesia  c10/1971  a9760 v210aWounds and Injuries1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/410792401048nas a2200157   4500008004100000022001400041245004100055210003600096260001200132300001400144490000600158520063400164653002400798100002100822856004700843       1971                        eng d  a0140-673600aThe aetiology of retrograde amnesia.0 aaetiology of retrograde amnesia  c08/1971  a356–3580 v23 aTo date, hypotheses of the ætiology of retrograde amnesia have focused on anatomical effects of traumatic lesions and on the presumed existence of short-term memory. The invariable association of retrograde amnesia with post-traumatic amnesia has been ignored as a clue to the origin of retrograde amnesia. It is suggested here that post-traumatic amnesia, by depriving preceding memories of a large proportion of their associated memories, leads to retrograde amnesia. The hypothesis accounts for the occurrence of retrograde amnesia in so many different situations and allows for the existence of very long retrograde amnesia.10aWounds and Injuries1 aWolpaw, Jonathan  uhttp://www.ncbi.nlm.nih.gov/pubmed/4105052