Decode the information structure underlying the neural representation of concepts
Importance
The ability to identify individual objects or events as members of a genus (eg, “knife”, “dog”, or “party”) is a fundamental aspect of human cognition. It allows us to quickly access a wealth of information regarding a newly encountered object or event and use it to guide our behavior. How is this information represented in the brain? We have used functional MRI to analyze brain activity patterns corresponding to hundreds of familiar concepts and quantitatively characterized the informational structure of these patterns. Our results indicate that conceptual knowledge is stored as neural activity patterns that encode sensory-motor and affective information about each concept, contrary to the long-held idea that conceptual representations are independent of sensory experience. -motor.
Summary
The nature of the representational code underlying conceptual knowledge remains a major unsolved problem in cognitive neuroscience. We assessed the extent to which different representation systems contribute to the instantiation of lexical concepts in high-level heteromodal cortical areas previously associated with semantic cognition. We found that lexical semantic information can be reliably decoded from a wide range of heteromodal cortical areas in frontal, parietal, and temporal cortex. In most of these areas, we have found a striking advantage for experience-based representational structures (i.e. encoding information about sensory-motor, affective and other characteristics of the phenomenal experience), with little evidence of independent taxonomic or distributional organization. These results were found independently for the concepts of object and event. Our results indicate that conceptual representations in the heteromodal cortex are based, at least in part, on experiential information. They also reveal that, in most heteromodal domains, event concepts have more heterogeneous representations (i.e., they are more easily decodable) than object concepts and other domains. beyond the traditional “semantic centers” contribute to semantic cognition, in particular the posterior cingulate gyrus and the precuneus.
Footnotes
- Accepted December 23, 2021.
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Author’s contributions: Study designed by LF; Research designed by LF, LLC and JRB; LF did some research; CJH provided new analytical reagents/tools; LF and J.-QT analyzed the data; LF wrote the paper; LLC and JRB reviewed/edited the manuscript; and JRB secured funding for the project.
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The authors declare no competing interests.
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This article is a direct PNAS submission.
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This article contains additional information online at https://www.pnas.org/lookup/suppl/doi:10.1073/pnas.2108091119/-/DCSupplemental.
- Copyright © 2022 the author(s). Published by PNAS.