03030nas a2200361   4500008004100000022001400041245013300055210006900188260001700257300001200274490000700286520191700293653001002210653001102220653002702231653001102258653000902269653002302278653001002301653001602311653002802327653001402355653001602369100001802385700001602403700001802419700002202437700001902459700001902478700002402497700002302521856012402544       2024                        eng d  a1876-475400aDoes vibrotactile stimulation of the auricular vagus nerve enhance working memory? A behavioral and physiological investigation.0 aDoes vibrotactile stimulation of the auricular vagus nerve enhan  c2024 Mar-Apr  a460-4680 v173 a<p><b>BACKGROUND: </b>Working memory is essential to a wide range of cognitive functions and activities. Transcutaneous auricular vagus nerve stimulation (taVNS) is a promising method to improve working memory performance. However, the feasibility and scalability of electrical stimulation are constrained by several limitations, such as auricular discomfort and inconsistent electrical contact.</p><p><b>OBJECTIVE: </b>We aimed to develop a novel and practical method, vibrotactile taVNS, to improve working memory. Further, we investigated its effects on arousal, measured by skin conductance and pupil diameter.</p><p><b>METHOD: </b>This study included 20 healthy participants. Behavioral response, skin conductance, and eye tracking data were concurrently recorded while the participants performed N-back tasks under three conditions: vibrotactile taVNS delivered to the cymba concha, earlobe (sham control), and no stimulation (baseline control).</p><p><b>RESULTS: </b>In 4-back tasks, which demand maximal working memory capacity, active vibrotactile taVNS significantly improved the performance metric d compared to the baseline but not to the sham. Moreover, we found that the reduction rate of d with increasing task difficulty was significantly smaller during vibrotactile taVNS sessions than in both baseline and sham conditions. Arousal, measured as skin conductance and pupil diameter, declined over the course of the tasks. Vibrotactile taVNS rescued this arousal decline, leading to arousal levels corresponding to optimal working memory levels. Moreover, pupil diameter and skin conductance level were higher during high-cognitive-load tasks when vibrotactile taVNS was delivered to the concha compared to baseline and sham.</p><p><b>CONCLUSION: </b>Our findings suggest that vibrotactile taVNS modulates the arousal pathway and could be a potential intervention for enhancing working memory.</p>10aAdult10aFemale10aGalvanic Skin Response10aHumans10aMale10aMemory, Short-Term10aPupil10aVagus Nerve10aVagus Nerve Stimulation10aVibration10aYoung Adult1 aTan, Gansheng1 aAdams, Josh1 aDonovan, Kara1 aDemarest, Phillip1 aWillie, Jon, T1 aBrunner, Peter1 aGorlewicz, Jenna, L1 aLeuthardt, Eric, C  uhttps://www.neurotechcenter.org/publications/2024/does-vibrotactile-stimulation-auricular-vagus-nerve-enhance-working-001915nas a2200349   4500008004100000022001400041245004100055210004000096260001600136300000900152490000700161520102100168653001001189653001001199653002001209653002001229653001101249653001101260653000901271653001801280653001601298653001601314100001301330700001901343700001601362700002201378700002501400700001901425700001901444700001701463856008501480       2024                        eng d  a2041-172300aGraded decisions in the human brain.0 aGraded decisions in the human brain  c2024 May 21  a43080 v153 a<p>Decision-makers objectively commit to a definitive choice, yet at the subjective level, human decisions appear to be associated with a degree of uncertainty. Whether decisions are definitive (i.e., concluding in all-or-none choices), or whether the underlying representations are graded, remains unclear. To answer this question, we recorded intracranial neural signals directly from the brain while human subjects made perceptual decisions. The recordings revealed that broadband gamma activity reflecting each individual's decision-making process, ramped up gradually while being graded by the accumulated decision evidence. Crucially, this grading effect persisted throughout the decision process without ever reaching a definite bound at the time of choice. This effect was most prominent in the parietal cortex, a brain region traditionally implicated in decision-making. These results provide neural evidence for a graded decision process in humans and an analog framework for flexible choice behavior.</p>10aAdult10aBrain10aChoice Behavior10aDecision Making10aFemale10aHumans10aMale10aParietal Lobe10aUncertainty10aYoung Adult1 aXie, Tao1 aAdamek, Markus1 aCho, Hohyun1 aAdamo, Matthew, A1 aRitaccio, Anthony, L1 aWillie, Jon, T1 aBrunner, Peter1 aKubanek, Jan  uhttps://www.neurotechcenter.org/publications/2024/graded-decisions-human-brain-0