Holistic Recollection via Pattern Completion Involves Hippocampal Subfield CA3

Research output: Contribution to journalArticle

Abstract

Episodic memories typically comprise multiple elements. A defining characteristic of episodic retrieval is holistic recollection, i.e., comprehensive recall of the elements a memorized event encompasses. A recent study implicated activity in the human hippocampus with holistic recollection of multi-element events based on cues (Horner et al., 2015). Here, we obtained ultra-high resolution functional neuroimaging data at 7 tesla in 30 younger adults (12 female) using the same paradigm. In accordance with anatomically inspired computational models and animal research, we found that metabolic activity in hippocampal subfield CA3 (but less pronounced in dentate gyrus) correlated with this form of mnemonic pattern completion across participants. Our study provides the first evidence in humans for a strong involvement of hippocampal subfield CA3 in holistic recollection via pattern completion.SIGNIFICANCE STATEMENT Memories of daily events usually involve multiple elements, although a single element can be sufficient to prompt recollection of the whole event. Such holistic recollection is thought to require reactivation of brain activity representing the full event from one event element ("pattern completion"). Computational and animal models suggest that mnemonic pattern completion is accomplished in a specific subregion of the hippocampus called CA3, but empirical evidence in humans was lacking. Here, we leverage the ultra-high resolution of 7 tesla neuroimaging to provide first evidence for a strong involvement of the human CA3 in holistic recollection of multi-element events via pattern completion.

Details

Authors
  • Xenia Grande
  • David Berron
  • Aidan J. Horner
  • James A. Bisby
  • Emrah Düzel
  • Neil Burgess
Organisations
External organisations
  • German Center for Neurodegenerative Diseases (DZNE), Bonn
  • Otto von Guericke University Magdeburg
  • University of York
  • University College London
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Neurosciences

Keywords

  • 7 T fMRI, hippocampal subfields, medial temporal lobe, memory, pattern completion, recollection
Original languageEnglish
Pages (from-to)8100-8111
Number of pages12
JournalThe Journal of neuroscience : the official journal of the Society for Neuroscience
Volume39
Issue number41
Publication statusPublished - 2019
Publication categoryResearch
Peer-reviewedYes