The neural representation of self is recapitulated in the brains of friends: A round-robin fMRI study

Humans continually form and update impressions of each other’s identities based on the disclosure of thoughts, feelings, and beliefs. At the same time, individuals also have specific beliefs and knowledge about their own self-concept. Over a decade of social neuroscience research has shown that retrieving information about the self and about other persons recruits similar areas of the medial prefrontal cortex (MPFC), however it remains unclear if an individual’s neural representation of self is reflected in the brains of well-known others or if instead the two representations share no common relationship. Here we examined this question in a tight-knit network of friends as they engaged in a round-robin trait evaluation task in which each participant was both perceiver and target for every other participant and in addition also evaluated their self. Using functional magnetic resonance imaging and a multilevel modeling approach, we show that multivoxel brain activity patterns in the MPFC during a person’s self-referential thought are correlated with those of friends when thinking of that same person. Moreover, the similarity of neural self/other patterns was itself positively associated with the similarity of self/other trait judgments ratings as measured behaviorally in a separate session. These findings suggest that accuracy in person perception may be predicated on the degree to which the brain activity pattern associated with an individual thinking about their own self-concept is similarly reflected in the brains of others.