RT Journal Article
SR Electronic
T1 The experience of vivid autobiographical reminiscence is supported by personal semantic representations in the precuneus
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 197665
DO 10.1101/197665
A1 Vishnu Sreekumar
A1 Dylan M. Nielson
A1 Troy A. Smith
A1 Simon J. Dennis
A1 Per B. Sederberg
YR 2017
UL http://biorxiv.org/content/early/2017/10/03/197665.abstract
AB Recent studies have suggested that the human posteromedial cortex (PMC), which includes core regions of the default mode network (DMN), plays an important role in episodic memory. Whereas various roles relating to self-relevant processing and memory retrieval have been attributed to different subsystems within this broad network, the nature of representations and the functional roles they support in these brain regions remain unspecified. Here, we describe the whole-brain networks that represent subjective, self-relevant aspects of real-world events during autobiographical recollection. Nine participants wore a device to record images from their lives for a period of two to four weeks (lifelogging phase) and indicated the personally-salient attributes (i.e., personal semantics) of each episode by choosing multiple content tags. Two to four weeks after the lifelogging phase, participants relived their experiences in an fMRI scanner cued by images chosen from their own lives. Representational Similarity Analysis revealed a broad network, including parts of the DMN, that represented personal semantics during autobiographical reminiscence. Furthermore, within this network, the right precuneus represented personally relevant content during vivid recollection but not during non-vivid recollection. The precuneus is a hub within the DMN and has been implicated in metacognitive ability for memory retrieval. Our results suggest a more specific mechanism underlying the phenomenology of vivid reminiscence, supported by personal semantic representations in the precuneus.