title: Converging evidence for the neuroanatomic basis of combinatorial semantics in the angular gyrus.
abstract: Human thought and language rely on the brain's ability to combine conceptual information. This fundamental process supports the construction of complex concepts from basic constituents. For example, both "jacket" and "plaid" can be represented as individual concepts, but they can also be integrated to form the more complex representation "plaid jacket." Although this process is central to the expression and comprehension of language, little is known about its neural basis. Here we present evidence for a neuroanatomic model of conceptual combination from three experiments. We predicted that the highly integrative region of heteromodal association cortex in the angular gyrus would be critical for conceptual combination, given its anatomic connectivity and its strong association with semantic memory in functional neuroimaging studies. Consistent with this hypothesis, we found that the process of combining concepts to form meaningful representations specifically modulates neural activity in the angular gyrus of healthy adults, independent of the modality of the semantic content integrated. We also found that individual differences in the structure of the angular gyrus in healthy adults are related to variability in behavioral performance on the conceptual combination task. Finally, in a group of patients with neurodegenerative disease, we found that the degree of atrophy in the angular gyrus is specifically related to impaired performance on combinatorial processing. These converging anatomic findings are consistent with a critical role for the angular gyrus in conceptual combination.
authors.affiliation: Penn FTD Center and Department of Neurology and Neuroscience Graduate Group, University of Pennsylvania, Philadelphia, Pennsylvania 19104 and amyprice@mail.med.upenn.edu.
authors.forename: Amy R
authors.initials: AR
authors.lastname: Price
authors.affiliation: Penn FTD Center and Department of Neurology and.
authors.forename: Michael F
authors.initials: MF
authors.lastname: Bonner
authors.affiliation: Department of Otolaryngology, Washington University in St. Louis, St. Louis, Missouri 63130.
authors.forename: Jonathan E
authors.initials: JE
authors.lastname: Peelle
authors.affiliation: Penn FTD Center and Department of Neurology and.
authors.forename: Murray
authors.initials: M
authors.lastname: Grossman
mesh_terms: D000328:Adult; D000368:Aged; D001245:Association Learning; D001931:Brain Mapping; D032882:Comprehension; D003704:Dementia / Q000473:pathology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007206:Individuality; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D010296:Parietal Lobe / Q000098:blood supply* / Q000502:physiology*; D012660:Semantics; D055815:Young Adult
chemical_list: D010100:Oxygen
keywords: angular gyrus; combinatorial semantics; compositionality; conceptual combination; semantic integration; semantic memory