Knowing me, knowing you: Resting-state functional connectivity of ventromedial prefrontal cortex dissociates memory related to self from a familiar other

Abstract

Material related to the self, as well as to significant others, often displays mnemonic superiority through its associations with highly organised and elaborate representations. Neuroimaging studies suggest this effect is related to activation in regions of medial prefrontal cortex (mPFC). Incidental memory scores for trait adjectives, processed in relation to the self, a good friend and David Cameron were collected. Scores for each referent were used as regressors in seed-based analyses of resting state fMRI data performed in ventral, middle and dorsal mPFC seeds, as well as hippocampal formation. Stronger memory for self-processed items was predicted by functional connnectivity between ventral mPFC, angular gyrus and middle temporal gyri. These regions are within the default mode network, linked to relatively automatic aspects of memory retrieval. In contrast, memory for items processed in relation to best friends, was better in individuals whose ventral mPFC showed relatively weak connectivity with paracingulate gyrus as well as positive connectivity with lateral prefrontal and parietal regions associated with controlled retrieval. These results suggest that mechanisms responsible for memory related to ourselves and personally-familiar people are partially dissociable and reflect connections between ventral mPFC, implicated in schema-based memory, and regions implicated in more automatic and controlled aspects of retrieval.