Hippocampal activity is associated with self-descriptiveness effect in memory, whereas self-reference effect in memory depends on medial prefrontal activity

Abstract

The self has long been regarded as a unique cognitive structure by virtue of its superior mnemonic abilities. Two separate effects result from this self memory facilitation: self-reference effect and self-descriptiveness effect in memory. Self-reference effect denotes that information processed with reference to the self is better remembered than information processed with reference to others, whereas self-descriptiveness effect indicates that items judged to be self-relevant is remembered better than items judged not to be relevant to self during self-reference task. Although there is a compelling connection between self-reference effect in memory and self mentalization processes indexed by the medial prefrontal activity, the underlying mechanisms of the self-descriptiveness effect in memory have remained underspecified. In the present fMRI study, we used a subsequent memory paradigm to examine the neural correlates of self-descriptiveness and self-reference effect in memory. Participants encoded personality traits while performing self-reference and other-reference task (judged the descriptiveness of the traits to themselves or a famous person "Bruce Lee"), and then were given a test of recognition memory outside the scanner. It is revealed that the hippocampal activity corresponded with self-descriptiveness effect in memory, but the activity of the medial prefrontal cortex and perirhinal cortex related to self-reference effect in memory. These findings suggested that the memory boost for self-relevant items relies on the enhanced relational binding mechanisms employed during self-relevant items.