[Contribution of the Medial Prefrontal Cortex to Social Memory]

Social memory is a form of episodic memories in multiple domains of social context. Functional neuroimaging studies have demonstrated that the medial prefrontal cortex (mPFC) plays an important role in social memories. However, little is known about the dissociable roles within mPFC in social memories. The purpose of this article was to summarize functional neuroimaging studies investigating social memories, and to propose a hypothetical model regarding the contribution of mPFC sub-regions to social memories. In this article, we divided mPFC into three sub-regions of the orbital, ventral, and dorsal regions. Functional neuroimaging studies have shown that the orbital mPFC (orbitofrontal cortex) contributes to the reward process in episodic memory, and that the reward-related activation is identified in primary, secondary, and social rewards. A role of the ventral mPFC has been found in the self-referential process, and the encoding operation of this process produces the self-reference effect in episodic memory. Activation in the dorsal mPFC has been observed in high demanding processes including cognitive control and in social cognition such as impression formation for others during episodic encoding and retrieval. The interactive mechanisms within three sub-regions of mPFC and between mPFC and the medial temporal lobe could contribute to social memories.