A Discussion of tACS Literature
Alpha power increase after transcranial alternating current stimulation at alpha frequency (α-tACS) reflects plastic changes rather than entrainment
Vossen, Alexandra, Joachim Gross, and Gregor Thut. 2015. 'Alpha power increase after transcranial alternating current stimulation at alpha frequency (α-tACS) reflects plastic changes rather than entrainment', Brain stimulation, 8: 499-508.
Summary: The mechanism of action for transcranial alternating current stimulation (tACS) is theorized to be via entrainment of neural activity. Vossen et al. set out to causally test the role of phase entrainment using a unique protocol of delivering intermittent periods of tACS that were either all phase aligned or randomly phase shifted (90-degree increments). The amplitude of alpha oscillations from tACS was increased for both in-phase and random-phase relative to sham, but the two conditions were not significantly different from each other. Thus, the authors conclude that the aftereffects of tACS are dependent on neural plasticity in the stimulated region and do not reflect a persistent entrainment effect.
Contributed by: Justin Riddle, PhD
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Every week, there are new and exciting scientific papers published on studies that investigated tACS. Reading and understanding these papers unfortunately requires both access to (sometimes quite expensive) scientific journals and in-depth "insider knowledge." Our goal is to share with you brief summaries of tACS studies that give you a big-picture idea of what the publications are about. There are too many studies to feature all of them but we will continuously update this page. If you have a specific study you would like to get featured, please contact us. The contributors are personnel from the Frohlich Lab and the Carolina Center for Neurostimulation.