The hippocampus as the switchboard between perception and memory

Treder, M. S. et al. (2021) The hippocampus as the switchboard between perception and memory. Proceedings of the National Academy of Sciences of the United States of America, 118(50), e211417111. (doi: 10.1073/pnas.2114171118)

Abstract

Adaptive memory recall requires a rapid and flexible switch from external perceptual reminders to internal mnemonic representations. However, owing to the limited temporal or spatial resolution of brain imaging modalities used in isolation, the hippocampal–cortical dynamics supporting this process remain unknown. We thus employed an object-scene cued recall paradigm across two studies, including intracranial electroencephalography (iEEG) and high-density scalp EEG. First, a sustained increase in hippocampal high gamma power (55 to 110 Hz) emerged 500 ms after cue onset and distinguished successful vs. unsuccessful recall. This increase in gamma power for successful recall was followed by a decrease in hippocampal alpha power (8 to 12 Hz). Intriguingly, the hippocampal gamma power increase marked the moment at which extrahippocampal activation patterns shifted from perceptual cue toward mnemonic target representations. In parallel, source-localized EEG alpha power revealed that the recall signal progresses from hippocampus to posterior parietal cortex and then to medial prefrontal cortex. Together, these results identify the hippocampus as the switchboard between perception and memory and elucidate the ensuing hippocampal–cortical dynamics supporting the recall process.

• Item Type: Articles
• Additional Information: This work was supported by Wellcome Trust/Royal Society Sir Henry Dale Fellowship 107672/Z/15/Z to B.P.S., European Research Council Starting Grant ERC-2017-StG 759432 to I.C., European Research Council Consolidator Grant 647954 to S.H., a grant from the Wolfson Foundation and Royal Society to S.H., Economic Social Sciences Research Council Grant ES/R010072/1 to S.H., and European Research Council Starting Grant ERC-STG2016-715714 to M.W.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Wimber, Professor Maria and Hanslmayr, Professor Simon and Roux, Dr Frederic
• Authors: Treder, M. S., Charest, I., Michelmann, S., Martín-Buro, M. C., Roux, F., Carceller-Benito, F., Ugalde-Canitrot, A., Rollings, D. T., Sawlani, V., Chelvarajah, R., Wimber, M., Hanslmayr, S., and Staresina, B. P.
• College/School: College of Medical Veterinary and Life Sciences > School of Psychology & Neuroscience
• Journal Name: Proceedings of the National Academy of Sciences of the United States of America
• Publisher: National Academy of Sciences
• ISSN: 0027-8424
• ISSN (Online): 1091-6490
• Published Online: 08 December 2021
• Copyright Holders: Copyright © The Author(s) 2021
• First Published: First published in Proceedings of the National Academy of Sciences of the United States of America 118(50): e211417111
• Publisher Policy: Reproduced under a Creative Commons licence

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
313261		Neural oscillations - a code for memory	Simon Hanslmayr	European Commission (EC)	N/A	NP - Centre for Cognitive Neuroimaging (CCNi)
314597		TIME - GLUING CROSS-MODAL MEMORIES VIA SYNCHRONISATION	Simon Hanslmayr	Economic and Social Research Council (ESRC)	ES/R010072/2	NP - Centre for Cognitive Neuroimaging (CCNi)
313514		The spatio-temporal representational architecture of memory	Maria Wimber	European Commission (EC)	N/A	NP - Centre for Cognitive Neuroimaging (CCNi)