VmPFC Drives Hippocampal Processing during Autobiographical Memory Recall Regardless of Remoteness.

Cornelia Mccormick,Amirhossein Jafarian,Eleanor A Maguire,Gareth R Barnes,Daniel N Barry

doi:10.1093/cercor/bhaa172

Abstract

Our ability to recall past experiences, autobiographical memories (AMs), is crucial to cognition, endowing us with a sense of self and underwriting our capacity for autonomy. Traditional views assume that the hippocampus orchestrates event recall, whereas recent accounts propose that the ventromedial prefrontal cortex (vmPFC) instigates and coordinates hippocampal-dependent processes. Here we sought to characterize the dynamic interplay between the hippocampus and vmPFC during AM recall to adjudicate between these perspectives. Leveraging the high temporal resolution of magnetoencephalography, we found that the left hippocampus and the vmPFC showed the greatest power changes during AM retrieval. Moreover, responses in the vmPFC preceded activity in the hippocampus during initiation of AM recall, except during retrieval of the most recent AMs. The vmPFC drove hippocampal activity during recall initiation and also as AMs unfolded over subsequent seconds, and this effect was evident regardless of AM age. These results recast the positions of the hippocampus and the vmPFC in the AM retrieval hierarchy, with implications for theoretical accounts of memory processing and systems-level consolidation.

Highlights

Our past experiences are captured in autobiographical memories (AMs)
Functional MRI studies over many years have shown that the hippocampus and ventromedial prefrontal cortex are among a distributed set of brain areas that are consistently engaged during the retrieval of such memories (Maguire 2001; Svoboda et al 2006; McDermott et al 2009; Spreng et al 2009)
Motivated by Barry et al (2018), they were asked to retrieve 12 AMs that were less than 1 month old (

Summary

Introduction

Our past experiences are captured in autobiographical memories (AMs). Functional MRI (fMRI) studies over many years have shown that the hippocampus and ventromedial prefrontal cortex (vmPFC) are among a distributed set of brain areas that are consistently engaged during the retrieval of such memories (Maguire 2001; Svoboda et al 2006; McDermott et al 2009; Spreng et al 2009). VmPFC lesions are associated with significant impairment of AM recollection (Della Sala et al 1993; Bertossi et al 2016; McCormick, Ciaramelli, et al 2018) and in addition can provoke confabulation. This involves the production of false AMs that patients believe to be true, perhaps due to an inability to select the appropriate components of memories and inhibit those that are irrelevant (Moscovitch and Melo 1997; Ciaramelli et al 2006; Gilboa and Marlatte 2017). It has been proposed that vmPFC may lead retrieval in circumstances where cues are generic and lack specificity (Robin and Moscovitch 2017), which could account for these findings

Methods

Results

Discussion

Conclusion