The Influence of Transcranial Direct Current Stimulation (tDCS) on the Perception of Actions Following Motor Skill Training

Abstract

Motor actions can be trained through physical and observational practice. The use of noninvasive brain stimulation during motor skill training has had facilitative effects on performance. The strengthening of new motor skill memories through consolidation requires at least four hours. This study examined the timescale relationship between motor and perceptual memory consolidation in response to tDCS over 6 and 24-hour intervals. Perceptual memories were evaluated through self-efficacy surveys and the trained 90° motor skill was evaluated through kinematic measures across three sessions (post-training, 6-hrs, and 24-hrs). Improvements in perceptual and motor memories occurred on different timescales, with motor faster than perceptual. Joint amplitudes significantly changed across sessions and seemed to contribute to higher self-efficacy ratings. Active tDCS produced two findings compared to Sham tDCS, (1) larger error/variability, and (2) smaller elbow amplitudes. Active tDCS did not influence the rate of motor or perceptual memory consolidation.