Verbal semantic expertise is associated with reduced functional connectivity between left and right anterior temporal lobes

Wu, Wei; Hoffman, Paul

Abstract

The left and right anterior temporal lobes (ATLs) encode semantic representations. They show graded hemispheric specialization in function, with the left ATL contributing preferentially to verbal semantic processing. We investigated the cognitive correlates of this organization, using resting-state functional connectivity as a measure of functional segregation between ATLs. We analyzed two independent resting-state fMRI datasets (n= 86 and n= 642) in which participants' verbal semantic expertise was measured using vocabulary tests. In both datasets, people with more advanced verbal semantic knowledge showed weaker functional connectivity between left and right ventral ATLs. This effect was highly specific. It was not observed for within-hemisphere connections between semantic regions (ventral ATL and inferior frontal gyrus (IFG), though it was found for left-right IFG connectivity in one dataset). Effects were not found for tasks probing semantic control, nonsemantic cognition, or face recognition. Our results suggest that hemispheric specialization in the ATLs is not an innate property but rather emerges as people develop highly detailed verbal semantic representations. We speculate that this effect is a consequence of the left ATL's greater connectivity with left-lateralized written word recognition regions, which causes it to preferentially represent meaning for advanced vocabulary acquired primarily through reading. [Abstract copyright: © The Author(s) 2024. Published by Oxford University Press.]

• Journal Article Type: Article
• Acceptance Date: Jun 4, 2024
• Online Publication Date: Jun 19, 2024
• Publication Date: Jun 4, 2024
• Deposit Date: Jun 20, 2024
• Publicly Available Date: Jun 20, 2024
• Journal: Cerebral Cortex
• Print ISSN: 1047-3211
• Electronic ISSN: 1460-2199
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 34
• Issue: 6
• Article Number: bhae256
• DOI: https://doi.org/10.1093/cercor/bhae256
• Keywords: Humans, Magnetic Resonance Imaging, Semantics, Neural Pathways - physiology - diagnostic imaging, anterior temporal lobe, Young Adult, Male, knowledge representation, Brain Mapping - methods, Adult, semantic cognition, Functional Laterality - physiology,
• Public URL: https://durham-repository.worktribe.com/output/2487065