title: Category-specific effects in semantic memory: category-task interactions suggested by fMRI.
abstract: Much work has investigated the neural representation of specific categories of knowledge, but relatively scant attention has been paid in the cognitive neuroscience literature to the semantic processes that contribute to semantic memory. In this study, we monitored regional cortical activity with fMRI while healthy young adults evaluated visually displayed NATURAL KIND, ARTIFACT, and ABSTRACT nouns with two standard tasks: Typicality judgments and Pleasantness judgments. We observed a significant interaction effect between the category of knowledge and the type of judgment used to evaluate members of these semantic categories. Typicality judgments recruited greater temporal-occipital activation relative to Pleasantness judgments of the same category, and this was seen for comparisons of all three semantic categories. However, when contrasted with Typicality judgments, Pleasantness judgments activated a different anatomic distribution for each semantic category. These findings are consistent with a dynamic approach to semantic memory that includes at least two components: semantic knowledge and semantic processes that interpret this knowledge in several ways depending on the particular semantic challenge.
authors.affiliation: Department of Neurology-2 Gibson, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104-4283, USA. mgrossma@mail.med.upenn.edu
authors.forename: Murray
authors.initials: M
authors.lastname: Grossman
authors.forename: Phyllis
authors.initials: P
authors.lastname: Koenig
authors.forename: John
authors.initials: J
authors.lastname: Kounios
authors.forename: Corey
authors.initials: C
authors.lastname: McMillan
authors.forename: Melissa
authors.initials: M
authors.lastname: Work
authors.forename: Peachie
authors.initials: P
authors.lastname: Moore
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory; D012660:Semantics