October 2020
Volume 20, Issue 11
Open Access
Vision Sciences Society Annual Meeting Abstract  |   October 2020
Perirhinal and Anterolateral Entorhinal Cortex Activity Patterns Reflect Perceived Visual Similarity of Highly Similar Objects
Author Affiliations & Notes
  • Kayla Ferko
    University of Western Ontario
    Brain and Mind Institute
  • Anna Blumenthal
    University of Toronto
  • Chris Martin
    University of Toronto
  • Daria Proklova
    University of Western Ontario
    Brain and Mind Institute
  • Timothy Bussey
    University of Western Ontario
    Brain and Mind Institute
  • Lisa Saksida
    University of Western Ontario
    Brain and Mind Institute
  • Ali Khan
    University of Western Ontario
    Robarts Research Institute
  • Stefan Köhler
    University of Western Ontario
    Brain and Mind Institute
  • Footnotes
    Acknowledgements  Canadian Institute for Health Research (CIHR); Natural Sciences and Engineering Research Council (NSERC)
Journal of Vision October 2020, Vol.20, 1197. doi:https://doi.org/10.1167/jov.20.11.1197
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Kayla Ferko, Anna Blumenthal, Chris Martin, Daria Proklova, Timothy Bussey, Lisa Saksida, Ali Khan, Stefan Köhler; Perirhinal and Anterolateral Entorhinal Cortex Activity Patterns Reflect Perceived Visual Similarity of Highly Similar Objects. Journal of Vision 2020;20(11):1197. doi: https://doi.org/10.1167/jov.20.11.1197.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Perirhinal Cortex (PRC) in the medial temporal lobe has been proposed to be an extension of the ventral visual stream (VVS; Murray, Bussey, Saksida, 2007). In support of this notion, evidence from numerous sources suggests that PRC supports discrimination of objects with high visual feature overlap. In the present fMRI study, we asked whether PRC activity patterns reflect the subjectively perceived visual similarity of objects, and whether these patterns are distinguishable at levels of similarity at which earlier VVS regions cannot distinguish between them. In addition, we investigated whether anterolateral entorhinal cortex (alERC), a region to which PRC projects, shows a similar response profile. We combined ultra-high resolution fMRI (isovoxel 1.7mm) in humans (N=23) with representational similarity analyses (RSA). Images of objects from multiple categories with differing degrees of visual similarity among exemplars were presented. We administered a variant of a 1-back task with catch trials that required identification of repetitions at the exemplar- and at the category-level. Participants also rated the perceived visual similarity in an inverse multi-dimensional scaling task (iMDS; Kriegeskorte and Mur, 2012). Behavioural results revealed sensitivity of performance on catch trials to variations in this similarity. RSA results of non-catch trials showed that patterns in early visual cortex, the lateral occipital region, PRC, and alERC (but not posteromedial ERC) correlated with participants’ perceived visual similarity of objects within categories, as expressed in the iMDS. Importantly, only PRC and alERC patterns exhibited such a relationship at the highest level of similarities. Furthermore, PRC activity patterns showed a relationship to perceived visual similarity that was uniquely related to participants’ own ratings. These findings suggest that the representational geometry of object representations in PRC and a downstream alERC region is tied to perceived similarity space, and that their fidelity is higher than in earlier VVS regions.

×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×