Hippocampal neurons code individual episodic memories in humans

Kolibius, L. D. et al. (2023) Hippocampal neurons code individual episodic memories in humans. Nature Human Behaviour, (doi: 10.1038/s41562-023-01706-6) (PMID:37798368) (Early Online Publication)

Abstract

The hippocampus is an essential hub for episodic memory processing. However, how human hippocampal single neurons code multi-element associations remains unknown. In particular, it is debated whether each hippocampal neuron represents an invariant element within an episode or whether single neurons bind together all the elements of a discrete episodic memory. Here we provide evidence for the latter hypothesis. Using single-neuron recordings from a total of 30 participants, we show that individual neurons, which we term episode-specific neurons, code discrete episodic memories using either a rate code or a temporal firing code. These neurons were observed exclusively in the hippocampus. Importantly, these episode-specific neurons do not reflect the coding of a particular element in the episode (that is, concept or time). Instead, they code for the conjunction of the different elements that make up the episode.

• Item Type: Articles
• Additional Information: This manuscript was supported by the following grants: European Research Council grant no. 647954 (S.H.), European Research Council grant no. 715714 (M.W.) and European Research Council grant no. 101001121 (B.P.S.).
• Status: Early Online Publication
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Hanslmayr, Professor Simon and van der Plas, Mr Mircea and Kreiselmeyer, Dr Gernot and ter Wal, Ms Marije and Wimber, Professor Maria and Hopfengärtner, Dr Rüdiger and Roux, Dr Frederic
• Authors: Kolibius, L. D., Roux, F., Parish, G., ter Wal, M., van der Plas, M., Chelvarajah, R., Sawlani, V., Rollings, D. T., Lang, J. D., Gollwitzer, S., Walther, K., Hopfengärtner, R., Kreiselmeyer, G., Hamer, H., Staresina, B. P., Wimber, M., Bowman, H., and Hanslmayr, S.
• College/School: College of Medical Veterinary and Life Sciences > School of Psychology & Neuroscience
• Journal Name: Nature Human Behaviour
• Publisher: Nature Research
• ISSN: 2397-3374
• ISSN (Online): 2397-3374
• Published Online: 05 October 2023
• Copyright Holders: Copyright © 2023 The Authors
• First Published: First published in Nature Human Behaviour 2023
• Publisher Policy: Reproduced under a Creative Commons License

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
313514		The spatio-temporal representational architecture of memory	Maria Wimber	European Commission (EC)	715714	SPN - Centre for Cognitive Neuroimaging (CCNi)