Selective Social Context-Dependent Role of the Left Medial Prefrontal Cortex in Communication Exchanges
Previous research showed that under uncertainty (when we are not sure about what the correct answer is) in informal contexts such as chatting with friends, we tend to provide any retrieved information indiscriminately. However, in more formal contexts, like a job interview, we apply a more conservative threshold and balance reporting some information while withholding other answers as a way to provide some information while keeping the accuracy high, if possible. The left medial prefrontal cortex (lmPFC) was suggested as one of the areas linked with self-referential processing in metacognitive decisions. In the present research, we used repetitive transcranial magnetic stimulation (rTMS) to assess the involvement of the lmPFC in two different types of social contexts: formal and informal. Three groups of participants were exposed for 15 minutes to an offline 1-Hz rTMS stimulation of either: (1) lmPFC, (2) control site (rmPFC) or (3) sham (placebo stimulation). Afterwards, participants answered difficult general knowledge questions and rated their confidence in the correctness of their answers. Finally, they decided if they would report or withhold those answers in a formal (job interview) and in informal (chatting with friends) contexts. There were significantly more reported than withheld answers in the informal context for all three groups. However, in the formal context, there were more withheld than reported answers in the lmPFC group, with no differences in the other two groups. No differences in confidence ratings between groups were found. These results suggest a selective involvement of the lmPFC in self-monitoring in formal contexts; its inhibition seems to highlight the need of accuracy in our answers in a job interview over the socially more acceptable behaviour of always providing an answer when asked.