Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.
Department of Neurophysiology and Pathophysiology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.
Curr Biol. 2014 Feb 3;24(3):333-9. doi: 10.1016/j.cub.2013.12.041. Epub 2014 Jan 23.
Novel methods for neuronal entrainment [1-4] provide the unique opportunity to modulate perceptually relevant brain oscillations [5, 6] in a frequency-specific manner and to study their functional impact on distinct cognitive functions. Recently, evidence has emerged that tACS (transcranial alternating current stimulation) can modulate cortical oscillations [7-9]. However, the study of electrophysiological effects has been hampered so far by the absence of concurrent electroencephalogram (EEG) recordings. Here, we applied 10 Hz tACS to the parieto-occipital cortex and utilized simultaneous EEG recordings to study neuronal entrainment during stimulation. We pioneer a novel approach for simultaneous tACS-EEG recordings and successfully separate stimulation artifacts from ongoing and event-related cortical activity. Our results reveal that 10 Hz tACS increases parieto-occipital alpha activity and synchronizes cortical oscillators with similar intrinsic frequencies to the entrainment frequency. Additionally, we demonstrate that tACS modulates target detection performance in a phase-dependent fashion highlighting the causal role of alpha oscillations for visual perception.
新型的神经元节律调制方法[1-4]为以特定频率调节与知觉相关的脑振荡[5,6]并研究其对不同认知功能的功能影响提供了独特的机会。最近，有证据表明 tACS（经颅交流电刺激）可以调节皮质振荡[7-9]。然而，由于缺乏同时进行的脑电图（EEG）记录，对电生理效应的研究一直受到阻碍。在这里，我们将 10 Hz 的 tACS 施加于顶枕叶皮层，并利用同时进行的 EEG 记录来研究刺激过程中的神经元节律同步。我们开创了一种同时进行 tACS-EEG 记录的新方法，并成功地将刺激伪迹与持续的和与事件相关的皮质活动分离开来。我们的结果表明，10 Hz 的 tACS 增加了顶枕叶的 alpha 活动，并使皮质振荡器与与同步频率具有相似固有频率的振荡器同步。此外，我们证明 tACS 以与相位相关的方式调节目标检测性能，突出了 alpha 振荡对视觉感知的因果作用。
