The effects of social-comparative feedback on corticospinal excitability and balance performance.
Social-comparative feedback informs individuals about their performance relative to a falsified group score. Providing positive (“performed better than the group”) social-comparative feedback enhances motivation, self-efficacy and balance performance, while negative (“worse than the group”) social-comparative feedback has the opposite effect. A possible mechanism explaining the motor benefits of social-comparative feedback is it produces a valent (emotional) response that subsequently, alters corticospinal excitability. This is based on studies observing correlations between valence, corticospinal excitability and balance performance. However, the neural processes contributing to the motor and cognitive benefits of social-comparative feedback have not yet been examined. Thus, the purpose of this study was to examine whether social-comparative feedback alters corticospinal excitability and consequently, balance performance. Thirty-six young adults (18 males) completed a balance task (i.e., standing on a stabilometer) eight times. After three of these trials, the control group received their performance outcome (i.e., time on balance) while the other two groups received positive or negative social-comparative feedback. Before and after each instance of feedback, corticospinal excitability was assessed using transcranial magnetic stimulation. Participants rated their perceived skill on the task as well as provided ratings of valence and arousal for the feedback as a manipulation check. Results indicated that by the end of the eight trials, participants in the negative group reported lower perceived skill (i.e., comparative balance ability) than those in the control and positive feedback groups (p<0.001). Despite this difference in feedback perception, all groups improved their balance performance by ~35% across all trials (p<0.001). This change in performance was not matched by changes in corticospinal excitability (p=0.340). These findings suggest that social-comparative feedback has minimal or no influence on corticospinal excitability and balance performance.