Get access

The perceptual richness of complex memory episodes is compromised by medial temporal lobe damage

Authors

  • Marie St-Laurent,

    Corresponding author
    1. Krembil Neuroscience Centre, Toronto Western Hospital, UHN, Toronto, Ontario, Canada
    2. Department of Psychology, University of Toronto, Ontario, Canada
    3. Rotman Research Institute at Baycrest Center for Geriatric Care, Toronto, Ontario, Canada
    Current affiliation:
    1. Marie St-Laurent is currently at Rotman Research Institute at Baycrest Center for Geriatric Care, Toronto, ON, Canada
    • Correspondence to: Marie St-Laurent, Rotman Research Institute at Baycrest Center for Geriatric Care, 3560 Bathurst Street, Toronto, ON, Canada M6A 2E1. E-mail: mstlaurent@research.baycrest.org

    Search for more papers by this author
  • Morris Moscovitch,

    1. Department of Psychology, University of Toronto, Ontario, Canada
    2. Rotman Research Institute at Baycrest Center for Geriatric Care, Toronto, Ontario, Canada
    3. Department of Psychology, Baycrest Center for Geriatric Care, Toronto, Ontario, Canada
    Search for more papers by this author
  • Rachel Jadd,

    1. Department of Psychology, York University, Faculty of Health, Toronto, Ontario, Canada
    Search for more papers by this author
  • Mary Pat McAndrews

    1. Krembil Neuroscience Centre, Toronto Western Hospital, UHN, Toronto, Ontario, Canada
    2. Department of Psychology, University of Toronto, Ontario, Canada
    Search for more papers by this author

ABSTRACT

Perceptual richness, a defining feature of episodic memory, emerges from the reliving of multimodal sensory experiences. Although the importance of the medial temporal lobe (MTL) to episodic memory retrieval is well documented, the features that determine its engagement are not well characterized. The current study assessed the relationship between MTL function and episodic memory's perceptual richness. We designed a laboratory memory task meant to capture the complexity of memory for life episodes, while manipulating memory's perceptual content. Participants encoded laboratory episodes with rich (film clips) and impoverished (written narratives) perceptual content that were matched for other characteristics such as personal significance, emotionality and story content. At retrieval, participants were probed to describe the stories' perceptual features and storyline. Participants also recalled autobiographical memories (AMs) in a comparison condition. We compared the performance of patients with unilateral medial temporal lobe epilepsy (mTLE) and healthy controls to assess how damage to the MTL affects retrieval in these conditions. We observed an overall decrease in detail count in the mTLE group, along with a disproportionate deficit in perceptual details that was most acute in the AM and the perceptually enriched film clip conditions. Our results suggest that the impaired sense of reliving the past that accompanies MTL insult is mediated by a paucity of perceptual episodic memory details. We also introduce a new protocol that successfully mimics naturalistic memories while benefiting from the experimental control provided by using laboratory stimuli. © 2014 Wiley Periodicals, Inc.

Get access to the full text of this article

Ancillary