Shpektor Anna, Nazarova Maria, Feurra Matteo
School of Psychology, Centre for Cognition and Decision Making, National Research University Higher School of Economics; Department of Experimental Psychology, University of Oxford.
Centre for Cognition and Decision Making, National Research University Higher School of Economics.
J Vis Exp. 2017 Sep 23(127):55839. doi: 10.3791/55839.
Transcranial Alternating Current Stimulation (tACS) is a neuromodulatory technique able to act through sinusoidal electrical waveforms in a specific frequency and in turn modulate ongoing cortical oscillatory activity. This neurotool allows the establishment of a causal link between endogenous oscillatory activity and behavior. Most of the tACS studies have shown online effects of tACS. However, little is known about the underlying action mechanisms of this technique because of the AC-induced artifacts on Electroencephalography (EEG) signals. Here we show a unique approach to investigate online physiological frequency-specific effects of tACS of the primary motor cortex (M1) by using single pulse Transcranial Magnetic Stimulation (TMS) to probe cortical excitability changes. In our setup, the TMS coil is placed over the tACS electrode while Motor Evoked Potentials (MEPs) are collected to test the effects of the ongoing M1-tACS. So far, this approach has mainly been used to study the visual and motor systems. However, the current tACS-TMS setup can pave the way for future investigations of cognitive functions. Therefore, we provide a step-by-step manual and video guidelines for the procedure.
经颅交流电刺激（tACS）是一种神经调节技术，能够通过特定频率的正弦电波形起作用，进而调节正在进行的皮层振荡活动。这种神经工具能够在内源性振荡活动与行为之间建立因果联系。大多数tACS研究都显示了tACS的即时效应。然而，由于脑电图（EEG）信号上的交流感应伪迹，对于该技术的潜在作用机制知之甚少。在此，我们展示了一种独特的方法，通过使用单脉冲经颅磁刺激（TMS）探测皮层兴奋性变化，来研究初级运动皮层（M1）的tACS的在线生理频率特异性效应。在我们的实验装置中，将TMS线圈放置在tACS电极上方，同时收集运动诱发电位（MEP）以测试正在进行的M1-tACS的效应。到目前为止，这种方法主要用于研究视觉和运动系统。然而，当前的tACS-TMS实验装置可为未来认知功能的研究铺平道路。因此，我们提供了该实验步骤的分步手册和视频指南。
