Out-of-phase transcranial alternating current stimulation modulates prestimulus EEG theta and alpha power

Poster Session A - Saturday, April 13, 2024, 2:30 – 4:30 pm EDT, Sheraton Hall ABC

Dr. Byoung-Kyong Min¹ (min_bk@korea.ac.kr), Yukyung Kim¹, Je-Hyeop Lee¹, Je-Choon Park¹, Jeongwook Kwon¹, Sangbin Yun¹, Jaewon Yang¹, Dr. Jeehye Seo¹; ¹Korea University

Transcranial alternating current stimulation (tACS) is a non-invasive neuromodulation technique used to enhance human cognitive function. This study aimed to investigate the effects of individualized-theta tACS delivered in-phase and out-of-phase between the left dorsolateral prefrontal cortex (lDLPFC) and dorsal anterior cingulate cortex (dACC) during inhibitory control performance. Twenty-four healthy participants were recruited for this study. The participants engaged in a Stroop task with the treatment of phase-lagged theta tACS over individually optimized high-density electrode montages targeting the lDLPFC and dACC. The tACS was exposed for 9 minutes per session: one for the in-phase (0 degree) and the other for the out-of-phase (180 degree) between the lDLPFC and dACC. We compared the reaction times and the prestimulus EEG theta and alpha power between the in-phase and out-of-phase conditions. The out-of-phase stimulation during the incongruent condition resulted in significantly reduced reaction times and enhanced prestimulus fronto-central theta and alpha activity. These findings imply that out-of-phase theta tACS potently modulates top-down preparatory inhibition, supporting the feasibility of employing phase-lagged tACS to enhance inhibitory control performance.

Topic Area: EXECUTIVE PROCESSES: Monitoring & inhibitory control