Wischnewski Miles, Schutter Dennis J L G
Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, The Netherlands.
Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, The Netherlands.
Clin Neurophysiol. 2017 Nov;128(11):2227-2232. doi: 10.1016/j.clinph.2017.08.029. Epub 2017 Sep 21.
Phase synchronization is suggested to be among the mechanisms that can explain the effects of transcranial alternating current stimulation (tACS). However, little is known about the effects of tACS on event-related oscillatory activity. Therefore the objective was to investigate frequency-related effects of frontal tACS on event-related oscillatory power.
In a double blind randomized controlled cross-over design, twenty-four participants received 12min of delta (2.5Hz), theta tACS (5Hz) and sham tACS at an intensity of 1mA peak-to-peak. Event-related delta- and theta-related oscillatory activity was recorded to reward- and punishment-related feedback signals.
Delta tACS decreased feedback-related oscillatory power in the 1.5 and 3.5Hz frequency range. This effect was driven by power changes below the tACS frequency stimulation.
Exogenous field potentials can attenuate event-related oscillatory activity in a rhythm slightly below the stimulation frequency. Our findings suggest an interaction between tACS and event-related rhythmic activity that extends beyond phase synchronization.
These findings add novel insights into the mechanisms of tACS after-effects.
相位同步被认为是能够解释经颅交流电刺激（tACS）效应的机制之一。然而，关于tACS对事件相关振荡活动的影响却知之甚少。因此，本研究的目的是探究额叶tACS对事件相关振荡功率的频率相关影响。
采用双盲随机对照交叉设计，24名参与者接受了12分钟的δ波（2.5Hz）、θ波tACS（5Hz）以及峰峰值为1mA的伪tACS刺激。记录与奖励和惩罚相关反馈信号的事件相关δ波和θ波振荡活动。
δ波tACS降低了1.5至3.5Hz频率范围内与反馈相关的振荡功率。这种效应是由低于tACS频率刺激的功率变化所驱动的。
外源性场电位可在略低于刺激频率的节律中减弱事件相关振荡活动。我们的研究结果表明，tACS与事件相关节律活动之间的相互作用超出了相位同步的范畴。
这些发现为tACS后效应的机制提供了新的见解。
