Embodiment in episodic memory through premotor-hippocampal coupling

Abstract

Episodic memory (EM) allows us to remember and relieve past events and experiences, depending on cortical-hippocampal reinstatement involved during encoding. Although it has been claimed that EM is fundamental to establish a sense of self across time, this has never been shown experimentally. Here we combine immersive virtual reality and fMRI and report stronger hippocampal reinstatement for scenes encoded under preserved sense of self, reflecting later recall performance. We further link the sense of self to EM showing that hippocampal reinstatement is coupled with reinstatement in premotor cortex, a key sense of self region. We extend these findings in a severe amnesic patient (caused by bilateral hippocampal damage), whose memory and re-experiencing lacked the normal dependency on the sense of self. Premotor-hippocampal coupling in EM describes how the self at encoding is neurally reinstated during the retrieval of past episodes, enabling a sense of self across time.