Friends, not foes: Magnetoencephalography as a tool to uncover brain dynamics during transcranial alternating current stimulation.
Friends, not foes: Magnetoencephalography as a tool to uncover brain dynamics during transcranial alternating current stimulation.
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DOI：
10.1016/j.neuroimage.2015.06.026
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发表时间：
2015-09
期刊：
影响因子：
5.7
通讯作者：
Weisz N
中科院分区：
文献类型：
--
作者：
Neuling T;Ruhnau P;Fuscà M;Demarchi G;Herrmann CS;Weisz N
大脑振荡被认为对正常的认知功能至关重要，而改变与认知功能障碍有关。为了证明它们对行为的因果作用，娱乐方法特别旨在通过有节奏的刺激驱动内源性振荡。在此背景下，经颅电刺激，特别是经颅交流电刺激（tACS）重新受到关注。这可能是由于精确定义振荡刺激特性的可能性。此外，比较tacs前和tacs后脑电图（EEG）的测量结果显示出令人印象深刻的调节。然而，由于大量的刺激伪影，到目前为止，tACS期间仍然是一个黑盒子。通过将波束形成技术应用于脑磁图（MEG）数据，我们成功地恢复了弱和强tACS时脑振荡幅度的调制。此外，我们还证明了视觉和听觉刺激引起的反应也可以在tac期间恢复。本研究的主要贡献是提供了关键证据，证明在持续的tACS过程中，即使在刺激频率下，振荡脑活动的微妙调节也可以被重建。未来的tACS实验将能够提供直接的生理学见解，以进一步了解大脑振荡对认知和行为的贡献。
Brain oscillations are supposedly crucial for normal cognitive functioning and alterations are associated with cognitive dysfunctions. To demonstrate their causal role on behavior, entrainment approaches in particular aim at driving endogenous oscillations via rhythmic stimulation. Within this context, transcranial electrical stimulation, especially transcranial alternating current stimulation (tACS), has received renewed attention. This is likely due to the possibility of defining oscillatory stimulation properties precisely. Also, measurements comparing pre-tACS with post-tACS electroencephalography (EEG) have shown impressive modulations. However, the period during tACS has remained a blackbox until now, due to the enormous stimulation artifact. By means of application of beamforming to magnetoencephalography (MEG) data, we successfully recovered modulations of the amplitude of brain oscillations during weak and strong tACS. Additionally, we demonstrate that also evoked responses to visual and auditory stimuli can be recovered during tACS. The main contribution of the present study is to provide critical evidence that during ongoing tACS, subtle modulations of oscillatory brain activity can be reconstructed even at the stimulation frequency. Future tACS experiments will be able to deliver direct physiological insights in order to further the understanding of the contribution of brain oscillations to cognition and behavior.