Activity in perirhinal and entorhinal cortex predicts perceived visual similarities among category exemplars with highest precision
Abstract
Vision neuroscience has made great strides in understanding the hierarchical organization of object representations along the ventral visual stream (VVS). How VVS representations capture fine-grained visual similarities between objects that observers subjectively perceive has received limited examination so far. In the current study, we addressed this question by focusing on perceived visual similarities among subordinate exemplars of real world-categories. We hypothesized that these perceived similarities are reflected with highest fidelity in neural activity patterns downstream from inferotemporal regions, namely in perirhinal and anterolateral entorhinal cortex in the medial temporal-lobe. To address this issue with fMRI, we administered a modified 1-Back task that required discrimination between category exemplars as well as categorization. Further, we obtained observer-specific ratings of perceived visual similarities, which predicted behavioural performance during scanning. As anticipated, we found that activity patterns in perirhinal and anterolateral entorhinal cortex predicted the structure of perceived visual similarity relationships among category exemplars, including its observer-specific component, with higher precision than any other VVS region. Our findings provide new evidence that subjective aspects of object perception that rely on fine-grained visual differentiation are reflected with highest fidelity in the medial temporal lobe.
Data availability
All data generated or analyzed during this study are included in the manuscript and supporting fields. Source data files have been provided for Figures 1, 2, 3, 4, 6,7
Article and author information
Author details
Funding
Canadian Institutes of Health Research (366062)
- Ali R Khan
Canadian Institutes of Health Research (366062)
- Stefan Köhler
Natural Sciences and Engineering Research Council of Canada
- Kayla M Ferko
Ontario Trillium Foundation
- Anna Blumenthal
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Human subjects: Human subjects: The study was approved by the Institutional Review Board at the University of Western Ontario (REB # 115283). Informed consent was obtained from each participant before the experiment, including consent to publish anonymized results.
Copyright
© 2022, Ferko et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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