Overclaiming and the medial prefrontal cortex: A transcranial magnetic stimulation study.

The tendency to claim more knowledge than one actually has is common and well documented; however, little research has focused on the neural mechanisms that underlie this phenomenon. The goal of the present study was to investigate the cortical correlates of overclaiming. Transcranial magnetic stimulation (TMS) was delivered to the medial prefrontal cortex (MPFC), supplementary motor area, and precuneus during the presentation of a series of words that participants were told made up a cultural IQ test. However, participants were not informed that 50% of the words were actually fabricated. False claiming was reduced following MPFC TMS. Furthermore, reaction time decreases following MPFC TMS indicated that participants engaged in less reflection during the task, suggesting a potential reduction in social monitoring of behavior.