title: Pathways to lexical ambiguity: fMRI evidence for bilateral fronto-parietal involvement in language processing.
abstract: Numerous functional neuroimaging studies reported increased activity in the pars opercularis and the pars triangularis (Brodmann's areas 44 and 45) of the left hemisphere during the performance of linguistic tasks. The role of these areas in the right hemisphere in language processing is not understood and, although there is evidence from lesion studies that the right hemisphere is involved in the appreciation of semantic relations, no specific anatomical substrate has yet been identified. This event-related functional magnetic resonance imaging study compared brain activity during the performance of language processing trials in which either dominant or subordinate meaning activation of ambiguous words was required. The results show that the ventral part of the pars opercularis both in the left and the right hemisphere is centrally involved in language processing. In addition, they highlight the bilateral co-activation of this region with the supramarginal gyrus of the inferior parietal lobule during the processing of this type of linguistic material. This study, thus, provides the first evidence of co-activation of Broca's region and the inferior parietal lobule, succeeding in further specifying the relative contribution of these cortical areas to language processing.
authors.affiliation: McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, 3801 University Street, Montreal, QC H3A 2B4, Canada; Centre for Research on Language, Mind, and Brain, McGill University, 3640 de la Montagne, Montreal, QC H3G 2A8, Canada. Electronic address: ekaterini.klepousniotou@mail.mcgill.ca.
authors.forename: Ekaterini
authors.initials: E
authors.lastname: Klepousniotou
authors.affiliation: Centre for Research on Language, Mind, and Brain, McGill University, 3640 de la Montagne, Montreal, QC H3G 2A8, Canada; School of Communication Sciences and Disorders, McGill University, 1266 Pine Avenue West, Montreal, QC H3G 1A8, Canada.
authors.forename: Vincent L
authors.initials: VL
authors.lastname: Gracco
authors.affiliation: McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, 3801 University Street, Montreal, QC H3A 2B4, Canada; Centre for Research on Language, Mind, and Brain, McGill University, 3640 de la Montagne, Montreal, QC H3G 2A8, Canada.
authors.forename: G Bruce
authors.initials: GB
authors.lastname: Pike
mesh_terms: D000328:Adult; D001931:Brain Mapping; D065711:Broca Area / Q000502:physiology; D032882:Comprehension / Q000502:physiology*; D005260:Female; D005625:Frontal Lobe / Q000502:physiology*; D006801:Humans; D007802:Language; D008279:Magnetic Resonance Imaging; D008297:Male; D010296:Parietal Lobe / Q000502:physiology*; D012660:Semantics; D014825:Vocabulary
keywords: BROCA’S area 44; Event-related fMRI; Homonymy; Inferior parietal lobule; Lexical ambiguity; Metaphor; Polysemy; Supramarginal gyrus