Multivoxel pattern similarity suggests the integration of temporal duration in hippocampal event sequence representations

Neuroimage. 2018 Sep:178:136-146. doi: 10.1016/j.neuroimage.2018.05.036. Epub 2018 May 24.

Abstract

Recent rodent work suggests the hippocampus may provide a temporal representation of event sequences, in which the order of events and the interval durations between them are encoded. There is, however, limited human evidence for the latter, in particular whether the hippocampus processes duration information pertaining to the passage of time rather than qualitative or quantitative changes in event content. We scanned participants while they made match-mismatch judgements on each trial between a study sequence of events and a subsequent test sequence. Participants explicitly remembered event order or interval duration information (Experiment 1), or monitored order only, with duration being manipulated implicitly (Experiment 2). Hippocampal study-test pattern similarity was significantly reduced by changes to order or duration in mismatch trials, even when duration was processed implicitly. Our findings suggest the human hippocampus processes short intervals within sequences and support the idea that duration information is integrated into hippocampal mnemonic representations.

Keywords: Event sequences; Functional magnetic resonance imaging; Hippocampus; Memory; Time.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Female
  • Functional Neuroimaging / methods*
  • Hippocampus / diagnostic imaging
  • Hippocampus / physiology*
  • Humans
  • Image Processing, Computer-Assisted / methods*
  • Magnetic Resonance Imaging
  • Male
  • Memory, Episodic*
  • Pattern Recognition, Visual / physiology*
  • Recognition, Psychology / physiology*
  • Time Perception / physiology*
  • Young Adult