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Neural Plasticity
Volume 2018, Article ID 1237962, 14 pages
https://doi.org/10.1155/2018/1237962
Research Article

Anodal tDCS over Primary Motor Cortex Provides No Advantage to Learning Motor Sequences via Observation

1Social Brain in Action Laboratory, Wales Institute for Cognitive Neuroscience, School of Psychology, Bangor University, Wales, UK
2MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK
3Institute of Neuroscience and Psychology, School of Psychology, University of Glasgow, Glasgow, UK

Correspondence should be addressed to Richard Ramsey; ku.ca.rognab@yesmar.r and Emily S. Cross; ku.ca.wogsalg@ssorc.ylime

Received 27 October 2017; Accepted 28 December 2017; Published 29 March 2018

Academic Editor: Nicole Wenderoth

Copyright © 2018 Dace Apšvalka et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

When learning a new motor skill, we benefit from watching others. It has been suggested that observation of others’ actions can build a motor representation in the observer, and as such, physical and observational learning might share a similar neural basis. If physical and observational learning share a similar neural basis, then motor cortex stimulation during observational practice should similarly enhance learning by observation as it does through physical practice. Here, we used transcranial direct-current stimulation (tDCS) to address whether anodal stimulation to M1 during observational training facilitates skill acquisition. Participants learned keypress sequences across four consecutive days of observational practice while receiving active or sham stimulation over M1. The results demonstrated that active stimulation provided no advantage to skill learning over sham stimulation. Further, Bayesian analyses revealed evidence in favour of the null hypothesis across our dependent measures. Our findings therefore provide no support for the hypothesis that excitatory M1 stimulation can enhance observational learning in a similar manner to physical learning. More generally, the results add to a growing literature that suggests that the effects of tDCS tend to be small, inconsistent, and hard to replicate. Future tDCS research should consider these factors when designing experimental procedures.