TY - JOUR T1 - A practical procedure for real-time functional mapping of eloquent cortex using electrocorticographic signals in humans. JF - Epilepsy Behav Y1 - 2009 A1 - Peter Brunner A1 - A L Ritaccio A1 - Lynch, Timothy M A1 - Emrich, Joseph F A1 - Adam J Wilson A1 - Williams, Justin C A1 - Aarnoutse, Erik J A1 - Ramsey, Nick F A1 - Leuthardt, E C A1 - H Bischof A1 - Gerwin Schalk KW - Adult KW - Brain Mapping KW - Cerebral Cortex KW - Electric Stimulation KW - Electrodes, Implanted KW - Electroencephalography KW - Epilepsy KW - Female KW - Humans KW - Male KW - Middle Aged KW - Practice Guidelines as Topic KW - Signal Processing, Computer-Assisted KW - Young Adult AB -

Functional mapping of eloquent cortex is often necessary prior to invasive brain surgery, but current techniques that derive this mapping have important limitations. In this article, we demonstrate the first comprehensive evaluation of a rapid, robust, and practical mapping system that uses passive recordings of electrocorticographic signals. This mapping procedure is based on the BCI2000 and SIGFRIED technologies that we have been developing over the past several years. In our study, we evaluated 10 patients with epilepsy from four different institutions and compared the results of our procedure with the results derived using electrical cortical stimulation (ECS) mapping. The results show that our procedure derives a functional motor cortical map in only a few minutes. They also show a substantial concurrence with the results derived using ECS mapping. Specifically, compared with ECS maps, a next-neighbor evaluation showed no false negatives, and only 0.46 and 1.10% false positives for hand and tongue maps, respectively. In summary, we demonstrate the first comprehensive evaluation of a practical and robust mapping procedure that could become a new tool for planning of invasive brain surgeries.

VL - 15 UR - http://www.ncbi.nlm.nih.gov/pubmed/19366638 IS - 3 ER - TY - JOUR T1 - Two-dimensional movement control using electrocorticographic signals in humans. JF - J Neural Eng Y1 - 2008 A1 - Gerwin Schalk A1 - Miller, K.J. A1 - Nicholas R Anderson A1 - Adam J Wilson A1 - Smyth, Matt A1 - Ojemann, J G A1 - Moran, D A1 - Jonathan Wolpaw A1 - Leuthardt, E C KW - Adolescent KW - Adult KW - Brain Mapping KW - Data Interpretation, Statistical KW - Drug Resistance KW - Electrocardiography KW - Electrodes, Implanted KW - Electroencephalography KW - Epilepsy KW - Female KW - Humans KW - Male KW - Movement KW - User-Computer Interface AB -

We show here that a brain-computer interface (BCI) using electrocorticographic activity (ECoG) and imagined or overt motor tasks enables humans to control a computer 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 clinical practicality, and also indicate promising directions for further research.

VL - 5 UR - http://www.ncbi.nlm.nih.gov/pubmed/18310813 IS - 1 ER - TY - JOUR T1 - ECoG factors underlying multimodal control of a brain-computer interface. JF - IEEE Trans Neural Syst Rehabil Eng Y1 - 2006 A1 - Adam J Wilson A1 - Felton, Elizabeth A A1 - Garell, P Charles A1 - Gerwin Schalk A1 - Williams, Justin C KW - Adult KW - Brain Mapping KW - Cerebral Cortex KW - Communication Aids for Disabled KW - Computer Peripherals KW - Evoked Potentials KW - Female KW - Humans KW - Imagination KW - Male KW - Man-Machine Systems KW - Neuromuscular Diseases KW - Systems Integration KW - User-Computer Interface KW - Volition AB -

Most current brain-computer interface (BCI) systems for humans use electroencephalographic activity recorded from the scalp, and may be limited in many ways. Electrocorticography (ECoG) is believed to be a minimally-invasive alternative to electroencephalogram (EEG) for BCI systems, yielding superior signal characteristics that could allow rapid user training and faster communication rates. In addition, our preliminary results suggest that brain regions other than the sensorimotor cortex, such as auditory cortex, may be trained to control a BCI system using similar methods as those used to train motor regions of the brain. This could prove to be vital for users who have neurological disease, head trauma, or other conditions precluding the use of sensorimotor cortex for BCI control.

VL - 14 UR - http://www.ncbi.nlm.nih.gov/pubmed/16792305 IS - 2 ER -