A meta-analysis of the effects of transcranial direct current brain stimulation on multiple realms of social behavior

Abstract

This meta-analysis examines the effects of transcranial direct current brain stimulation (tDCS) applied to the prefrontal cortex on a variety of social behaviors including aggression, overeating, impulsivity, bias, honesty, and risk-taking. 48 studies were included in this meta-analysis, N=2,196. tDCS was found to have an overall effect size of d=-0.2, which means tDCS reduced the undesirable behavior by a small but significant amount. tDCS was most effective at reducing risk-taking behavior, bias, and overeating. tDCS was not significantly effective at reducing aggression, impulsivity, or dishonesty. Moderators such as brain region of interest, online versus offline stimulation, within versus between subjects designs, dose, and duration were examined. Publication bias was also examined with three different tools, and significant publication bias was found in the literature in this meta-analysis. These findings indicate high likelihood that many tDCS studies with null findings exist and have not been added to our published literature. Taken together, these results suggest that tDCS works better on some social behaviors than others, but overall, can reduce antisocial behavior by a small but significant amount.Keywords: transcranial direct current stimulation, meta-analysis, social psychology, prefrontal cortex, prosocial behavior