Elucidating the role of the posterior medial frontal cortex in social conflict processing

A fundamental function of the brain is learning via new information. Studies investigating the neural basis of information-based learning processes indicate an important role played by the posterior medial frontal cortex (pMFC) in representing conflict between an individual's expectation and new information. However, specific function of the pMFC in this process remains relatively indistinct. Particularly, it's unclear whether the pMFC plays a role in the detection of conflict of incoming information, or the update of their belief after new information is provided. In an fMRI scanner, twenty-eight Japanese students viewed scenarios depicting various pro-social/anti-social behaviors. Participants rated how likely Japanese and South Korean students would perform each behavior, followed by feedback of the actual likelihood. They were then asked to rerate the scenarios after the fMRI session. Participants updated their second estimates based on feedback, with estimate changes more pronounced for favorable feedback (e.g., higher likelihood of pro-social behavior than expected) despite nationality, indicating participants were willing to view other people favorably. The fMRI results demonstrated activity in a part of the pMFC, the dorsomedial prefrontal cortex (dmPFC), was correlated with social conflict (difference between participant's estimate and actual likelihood), but not the corresponding belief update. Importantly, activity in a different part within the dmPFC was more sensitive to unfavorable trials compared to favorable trials. These results indicate sensitivity in the pMFC (at least within the dmPFC) relates to conflict between desirable outcomes versus reality, as opposed to the associated update of belief.