Feedback processing in the context of social comparison

In many situations, social comparison calls for the evaluation of one ' s own performance in relative terms by taking into account the performances of other people. Here, we investigated the effects of social comparison on performance monitoring with the help of ERPs. Two participants performed two identical experiments at the same time and in the same room. Instructions created a social context of cooperation by suggesting that participants were performing the same task for the maximization of a shared bonus. The experiment was a response-choice task with two feedback signals presented in sequence after each response: one feedback described the personal performance (personal feedback) and one reflected the other participant's performance (nonpersonal feedback). In the present experiment, social comparison should induce interpretations of the second feedback in relative terms (e.g., "I performed better") according to the quality of the first feedback. ERP results showed that the first nonpersonal feedback affected the fronto-central P3 component (P3a) evoked by the second personal feedback but did not modulate the feedback-related negativity (FRN). The P3a component evoked by the personal feedback was larger when the comparison against the preceding nonpersonal feedback signaled that the personal performance was worse than the other participant's performance. Interestingly, the effect was prominent over bilateral fronto-central electrodes (FC3, FC4). The observed P3a effect might indicate the recruitment of attentional resources when the comparison between personal and nonpersonal performance shows that the personal performance was not as good as the performance of others.