The neural representation of the self in relation to close others using fMRI repetition suppression.

Prior neuroimaging studies revealed neural correlates for various aspects of self-processing but did not identify the neural representation of the self in terms of personality traits isolated from other processes. To identify this representation of the self, we used functional magnetic resonance imaging (fMRI) repetition suppression which is based on the assumption that repeated processing of the same stimulus results in decreased activation of the neural population representing this stimulus. Participants read two successive trait implying behavioral descriptions in which the agent was twice the self, the self and a close other or two different close others. The results revealed suppression in the ventral part of the medial prefrontal cortex (vmPFC) for repeated self-descriptions, and also when a close other description preceded a self-description (but not in the reverse order). We conclude that the vmPFC represents knowledge on one's personality, and that close others automatically recruit this self-presentation because of an asymmetric perceived similarity in which close others are typically seen as more similar to the self than the other way around.