title: Effects of representational distance between meanings on the neural correlates of semantic ambiguity.
abstract: Psycholinguistic research demonstrates that representational distance between meanings influences recognition of ambiguous words. Our goal was to investigate whether the neural correlates of ambiguity are also modulated by representational distance as a function of syntactic similarity (i.e., grammatical class) and meaning dominance. In an event-related fMRI experiment, participants completed a visual lexical decision task that included balanced and unbalanced noun-noun and noun-verb homonyms, unambiguous words, and nonwords. Syntactic similarity effects were observed in left inferior frontal regions, with greater activation for noun-verb than noun-noun homonyms. Meaning dominance effects were observed in left middle and superior temporal regions, with greater activation for balanced than unbalanced homonyms. These findings indicate that the behavioral cost associated with processing ambiguous word meanings, modulated by syntactic similarity and meaning dominance, is reflected in the neural systems underlying ambiguity processing, as frontal and temporal regions are recruited by increased competition as a function of representational distance.
authors.affiliation: Department of Speech & Hearing Science, University of Illinois at Urbana-Champaign, United States. Electronic address: grindrod@illinois.edu.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Grindrod
authors.affiliation: Department of Communication Sciences & Disorders, University of South Carolina, United States.
authors.forename: Emily O
authors.initials: EO
authors.lastname: Garnett
authors.affiliation: Department of Communication Sciences & Disorders, University of South Carolina, United States.
authors.forename: Svetlana
authors.initials: S
authors.lastname: Malyutina
authors.affiliation: Department of Communication Sciences & Disorders, University of South Carolina, United States.
authors.forename: Dirk B
authors.initials: DB
authors.lastname: den Ouden
mesh_terms: D000328:Adult; D001931:Brain Mapping; D005260:Female; D005625:Frontal Lobe / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D012660:Semantics; D013702:Temporal Lobe / Q000502:physiology*; D055815:Young Adult
keywords: Grammatical class; Inferior frontal gyrus; Lexical ambiguity; Meaning dominance; Middle temporal gyrus; Representational distance; Superior temporal gyrus; fMRI