Poster C78, Sunday, March 26, 5:00 – 7:00 pm, Pacific Concourse
Semantic Word Category Deficits in Neurodegenerative Diseases
Zubaida Shebani1,2, Karalyn Patterson1,3, Peter J. Nestor4, Lara Z. Diaz-de-Grenu3,5, Kate Dawson3, Friedemann Pulvermuller1,6,7; 1Medical Research Council, Cognition and Brain Sciences Unit, Cambridge, 2Linguistics Department, College of Humanities and Social Sciences, United Arab Emirates University, UAE, 3Department of Clinical Neurosciences, University of Cambridge, 4German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany, 5Tecnalia Research and Innovation Center, Health Division, Neurotechnology Unit, Bizkaia Technology Park, Derio, Spain, 6Brain Language Laboratory, Department of Philosophy and Humanities, WE4, Freie Universität Berlin, Berlin, Germany, 7Berlin School of Mind and Brain, Humboldt Universität zu Berlin, Berlin, Germany
It has long been recognized that perisylvian language cortex and some neighbouring extrasylvian regions play a major role in lexical and semantic processing. However, the involvement of additional cortical areas in the processing of different semantic word categories remains controversial. We investigated word processing in two groups of patients whose neurodegenerative diseases affect specific parts of the brain while leaving ‘core’ language areas intact. The aim was to determine whether brain regions affected in each patient group make a necessary contribution to the processing of different semantic word categories. Cohorts with (i) Semantic Dementia (SD), who have anterior temporal-lobe atrophy, and (ii) Posterior Cortical Atrophy (PCA), who have parieto-occipital atrophy, performed tests of immediate and delayed serial recall (ISR, DSR), on words from five different semantic categories: colour (e.g., yellow), form (oval), number (seven), spatial prepositions (under) and function words (also). Word-frequency was matched between the two visual word categories (colour and form) and across the three other categories (number, prepositions, function words). In both ISR and DSR, SD patients were reliably impaired relative to controls on words from the colour and form categories. ISR performance in the PCA cases did not show a clear category specific pattern, but in DSR, a clear category difference emerged with significantly poorer performance on spatial prepositions. The patterns of performance on the serial recall tasks as a function of semantic category demonstrates that specific extrasylvian regions of the brain are differentially involved in the processing of different semantic categories of words.
Topic Area: LANGUAGE: Semantic