The effect of dual-site theta-range transcranial alternating current stimulation over the frontoparietal network on bimanual coordination in young adults

Abstract

In this study, dual-site theta range transcranial alternating current stimulation (tACS) was used to (de)synchronize the right dorsolateral prefrontal cortex and the right posterior parietal cortex and study its effects on the performance of a new bimanual visuomotor task, and its effects on motor learning and retention of this task. Fifteen right-handed healthy volunteers had to perform a new bimanual visuomotor task. Concurrent with the execution of the task, participants received either frontoparietal in-phase or anti-phase dual-site tACS. Performance of the bimanual visuomotor task was the main outcome measure, expressed as “average trace deviation” and “average target deviation”. No significant differences were found between in-phase and anti-phase tACS for average trace deviation. For average target deviation, in-phase tACS yielded significantly better performance at the beginning, at the end and 15 minutes after stimulation as compared to anti-phase tACS. This indicated that frontoparietal synchronization is beneficial for the execution of the average target deviation part of a bimanual coordination task, relative to frontoparietal desynchronization. There were no significant differences found in motor learning or retention between in-phase and anti-phase tACS. We concluded that frontoparietal synchronization, using in-phase tACS, had a beneficial effect on the accuracy of bimanual coordination, but there was no effect on motor learning or retention.