title: Structure and deterioration of semantic memory: a neuropsychological and computational investigation.
abstract: Wernicke (1900, as cited in G. H. Eggert, 1977) suggested that semantic knowledge arises from the interaction of perceptual representations of objects and words. The authors present a parallel distributed processing implementation of this theory, in which semantic representations emerge from mechanisms that acquire the mappings between visual representations of objects and their verbal descriptions. To test the theory, they trained the model to associate names, verbal descriptions, and visual representations of objects. When its inputs and outputs are constructed to capture aspects of structure apparent in attribute-norming experiments, the model provides an intuitive account of semantic task performance. The authors then used the model to understand the structure of impaired performance in patients with selective and progressive impairments of conceptual knowledge. Data from 4 well-known semantic tasks revealed consistent patterns that find a ready explanation in the model. The relationship between the model and related theories of semantic representation is discussed.
authors.affiliation: Medical Research Council Cognition and Brain Sciences Unit, Cambridge, UK. tim.rogers@mrc-cbu.cam.ac.uk
authors.forename: Timothy T
authors.initials: TT
authors.lastname: Rogers
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Lambon Ralph
authors.forename: Peter
authors.initials: P
authors.lastname: Garrard
authors.forename: Sasha
authors.initials: S
authors.lastname: Bozeat
authors.forename: James L
authors.initials: JL
authors.lastname: McClelland
authors.forename: John R
authors.initials: JR
authors.lastname: Hodges
authors.forename: Karalyn
authors.initials: K
authors.lastname: Patterson
mesh_terms: D000849:Anomia / Q000523:psychology; D001245:Association Learning; D003210:Concept Formation; D003704:Dementia / Q000523:psychology; D004193:Discrimination Learning; D006801:Humans; D011939:Mental Recall; D008960:Models, Psychological; D009483:Neuropsychological Tests / Q000706:statistics & numerical data*; D010364:Pattern Recognition, Visual; D011594:Psychometrics; D011597:Psychomotor Performance; D011930:Reaction Time; D012660:Semantics; D014706:Verbal Learning