{"title":"Phase-specific alpha tACS over the dlPFC does not enhance cognitive reappraisal or autonomic responses: A sham-controlled crossover study.","authors":"Catarina Gomes Coelho, Jorge Leite, Gabriela Gonzaga, Paulo Machado, Sandra Carvalho","doi":"10.3934/Neuroscience.2026022","DOIUrl":null,"url":null,"abstract":"<p><strong>Background: </strong>Cognitive reappraisal (CR) relies on prefrontal top-down control over limbic systems, with the dorsolateral prefrontal cortex (dlPFC) playing a central regulatory role. Alpha-frequency transcranial alternating current stimulation (α-tACS) can modulate cortical oscillations; yet, its causal contribution to emotion regulation (ER) remains unclear.</p><p><strong>Objective: </strong>In this study, we investigated whether in-phase or anti-phase alpha-tACS influenced subjective and physiological responses during cognitive reappraisal of negative emotional stimuli.</p><p><strong>Methods: </strong>Forty-two healthy young adults completed three counterbalanced sessions (in-phase, anti-phase, sham) in a single-blind, sham-controlled crossover design. During α-tACS or sham, participants applied three CR strategies (positive, fictional, distancing) while viewing negative and neutral film clips. Valence, arousal, heart rate (HR), skin conductance (SC), respiratory rate (RR), and pre/post-session affect (PANAS) were recorded.</p><p><strong>Results: </strong>The Emotional Movie Database (EMDB) emotional stimuli elicited the expected subjective and autonomic responses, confirming that the task engaged emotional-reactivity processes. Participants also showed a typical habituation pattern in physiological measures across blocks. However, neither in-phase nor anti-phase alpha-tACS was associated with measurable changes in subjective emotional ratings or autonomic responses relative to sham under the experimental conditions.</p><p><strong>Conclusion: </strong>This study provides the first evaluation of phase-specific alpha-tACS during cognitive reappraisal using film-based stimuli. Under the experimental conditions, no measurable effects of in-phase or anti-phase stimulation on subjective or autonomic measures of ER were observed. Future studies incorporating individualized stimulation frequencies, multi-session protocols, closed-loop stimulation, and concurrent electrophysiological recordings may help clarify the conditions under which phase-specific tACS influences ER.</p>","PeriodicalId":7732,"journal":{"name":"AIMS Neuroscience","volume":"13 3","pages":"483-509"},"PeriodicalIF":4.3000,"publicationDate":"2026-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13658056/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"AIMS Neuroscience","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.3934/Neuroscience.2026022","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2026/1/1 0:00:00","PubModel":"eCollection","JCR":"Q2","JCRName":"NEUROSCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
Background: Cognitive reappraisal (CR) relies on prefrontal top-down control over limbic systems, with the dorsolateral prefrontal cortex (dlPFC) playing a central regulatory role. Alpha-frequency transcranial alternating current stimulation (α-tACS) can modulate cortical oscillations; yet, its causal contribution to emotion regulation (ER) remains unclear.
Objective: In this study, we investigated whether in-phase or anti-phase alpha-tACS influenced subjective and physiological responses during cognitive reappraisal of negative emotional stimuli.
Methods: Forty-two healthy young adults completed three counterbalanced sessions (in-phase, anti-phase, sham) in a single-blind, sham-controlled crossover design. During α-tACS or sham, participants applied three CR strategies (positive, fictional, distancing) while viewing negative and neutral film clips. Valence, arousal, heart rate (HR), skin conductance (SC), respiratory rate (RR), and pre/post-session affect (PANAS) were recorded.
Results: The Emotional Movie Database (EMDB) emotional stimuli elicited the expected subjective and autonomic responses, confirming that the task engaged emotional-reactivity processes. Participants also showed a typical habituation pattern in physiological measures across blocks. However, neither in-phase nor anti-phase alpha-tACS was associated with measurable changes in subjective emotional ratings or autonomic responses relative to sham under the experimental conditions.
Conclusion: This study provides the first evaluation of phase-specific alpha-tACS during cognitive reappraisal using film-based stimuli. Under the experimental conditions, no measurable effects of in-phase or anti-phase stimulation on subjective or autonomic measures of ER were observed. Future studies incorporating individualized stimulation frequencies, multi-session protocols, closed-loop stimulation, and concurrent electrophysiological recordings may help clarify the conditions under which phase-specific tACS influences ER.
期刊介绍:
AIMS Neuroscience is an international Open Access journal devoted to publishing peer-reviewed, high quality, original papers from all areas in the field of neuroscience. The primary focus is to provide a forum in which to expedite the speed with which theoretical neuroscience progresses toward generating testable hypotheses. In the presence of current and developing technology that offers unprecedented access to functions of the nervous system at all levels, the journal is designed to serve the role of providing the widest variety of the best theoretical views leading to suggested studies. Single blind peer review is provided for all articles and commentaries.