140. Effects of transcranial alternating current stimulation (tACS) on spontaneous motor tempo and sensorimotor synchronization: Preliminary data

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• 作者：F. Giovannelli ; I. Innocenti ; M. Feurra ; E. Santarnecchi ; A. Borgheresi ; E. Del Sordo ; A. Ragazzoni ; G. Zaccara ; M.P. Viggiano ; S. Rossi ; M. Cincotta
• 刊名：Clinical Neurophysiology
• 出版年：2013
• 出版时间：November, 2013
• 年：2013
• 卷：124
• 期：11
• 页码：e220
• 全文大小：35 K

文摘

We used transcranial alternating current stimulation (tACS) to modulate brain oscillations during spontaneous motor tempo and sensorimotor synchronization tasks to evaluate the effect of specific frequencies on motor performance. Six healthy subjects performed self-paced finger movements and auditory-paced finger tapping (synchronization-continuation task) with isochronous rhythmic sequences of 500 and 1500 ms interstimulus intervals (ISI). During each task, tACS was delivered to the left M1 (¡°reference¡± electrode on Pz) at an intensity of 1 mA in 5 randomized conditions: 5, 10, 20, 40 Hz, and sham. Baseline recordings (without tACS) were performed before and after each experimental session. In synchronization task with sequences of ISI 500 ms, 20 Hz tACS modified anticipatory mechanisms as revealed by a reduction of the negative mean asynchrony between the onset of the auditory cue and the motor response. However, this effect did not reach statistical significance due to the small sample. No effect emergent in the other conditions. We hypothesize that the reduction of the negative mean asynchrony may reflect a slowing of the motor output. These preliminary data are in line with previous studies in literature reporting specific effects of tACS at beta frequency on motor functions and cortical excitability.