Modulation of the semantic system by word imageability. Neuroimage 2005 Aug 01;27(1):188-200
Date
05/17/2005Pubmed ID
15893940DOI
10.1016/j.neuroimage.2005.04.012Scopus ID
2-s2.0-22044453651 (requires institutional sign-in at Scopus site) 279 CitationsAbstract
A prevailing neurobiological theory of semantic memory proposes that part of our knowledge about concrete, highly imageable concepts is stored in the form of sensory-motor representations. While this theory predicts differential activation of the semantic system by concrete and abstract words, previous functional imaging studies employing this contrast have provided relatively little supporting evidence. We acquired event-related functional magnetic resonance imaging (fMRI) data while participants performed a semantic similarity judgment task on a large number of concrete and abstract noun triads. Task difficulty was manipulated by varying the degree to which the words in the triad were similar in meaning. Concrete nouns, relative to abstract nouns, produced greater activation in a bilateral network of multimodal and heteromodal association areas, including ventral and medial temporal, posterior-inferior parietal, dorsal prefrontal, and posterior cingulate cortex. In contrast, abstract nouns produced greater activation almost exclusively in the left hemisphere in superior temporal and inferior frontal cortex. Increasing task difficulty modulated activation mainly in attention, working memory, and response monitoring systems, with almost no effect on areas that were modulated by imageability. These data provide critical support for the hypothesis that concrete, imageable concepts activate perceptually based representations not available to abstract concepts. In contrast, processing abstract concepts makes greater demands on left perisylvian phonological and lexical retrieval systems. The findings are compatible with dual coding theory and less consistent with single-code models of conceptual representation. The lack of overlap between imageability and task difficulty effects suggests that once the neural representation of a concept is activated, further maintenance and manipulation of that information in working memory does not further increase neural activation in the conceptual store.
Author List
Sabsevitz DS, Medler DA, Seidenberg M, Binder JRAuthor
Jeffrey R. Binder MD Professor in the Neurology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AdolescentAdult
Decision Making
Female
Humans
Image Processing, Computer-Assisted
Imagination
Magnetic Resonance Imaging
Male
Psycholinguistics
Reaction Time
Reading
Semantics
