Modulation of Somatosensory Alpha Rhythm by Transcranial Alternating Current Stimulation at Mu-Frequency

Frontiers in Human Neuroscience

Till Nierhaus¹  Bernhard Sehm²  Arno Villringer²  Christopher Gundlach⁴  Matthias M. Müller⁴ 

[1] Center for Cognitive Neuroscience Berlin, Freie UniversitätBerlin, Germany;Clinic for Cognitive Neurology, University of LeipzigLeipzig, Germany;Department for Neurology, Max Planck Institute for Human Cognitive and Brain SciencesLeipzig, Germany;Institute of Psychology, University of LeipzigLeipzig, Germany;MindBrainBody Institute, Berlin School of Mind and Brain, Charité Universitätsmedizin Berlin, Humboldt University of BerlinBerlin, Germany;

关键词: transcranial alternating current stimulation;    tACS;    mu-alpha;    brain oscillations;    electroencephalogram;    EEG;   

DOI  :  10.3389/fnhum.2017.00432

来源: DOAJ

【 摘 要 】

Introduction: Transcranial alternating current stimulation (tACS) is emerging as an interventional tool to modulate different functions of the brain, potentially by interacting with intrinsic ongoing neuronal oscillations. Functionally different intrinsic alpha oscillations are found throughout the cortex. Yet it remains unclear whether tACS is capable of specifically modulating the somatosensory mu-rhythm in amplitude.Objectives: We used tACS to modulate mu-alpha oscillations in amplitude. When compared to sham stimulation we expected a modulation of mu-alpha oscillations but not visual alpha oscillations by tACS.Methods: Individual mu-alpha frequencies were determined in 25 participants. Subsequently, blocks of tACS with individual mu-alpha frequency and sham stimulation were applied over primary somatosensory cortex (SI). Electroencephalogram (EEG) was recorded before and after either stimulation or sham. Modulations of mu-alpha and, for control, visual alpha amplitudes were then compared between tACS and sham.Results: Somatosensory mu-alpha oscillations decreased in amplitude after tACS was applied at participants’ individual mu-alpha frequency. No changes in amplitude were observed for sham stimulation. Furthermore, visual alpha oscillations were not affected by tACS or sham, respectively.Conclusion: Our results demonstrate the capability of tACS to specifically modulate the targeted somatosensory mu-rhythm when the tACS frequency is tuned to the individual endogenous rhythm and applied over somatosensory areas. Our results are in contrast to previously reported amplitude increases of visual alpha oscillations induced by tACS applied over visual cortex. Our results may point to a specific interaction between our stimulation protocol and the functional architecture of the somatosensory system.

【 授权许可】

Unknown