Dissociation of quantifiers and object nouns in speech in focal neurodegenerative disease

Sharon Ash, Kylie Ternes, Teagan Bisbing, Nam Eun Min, Eileen Moran, Collin York, Corey T. McMillan, David J. Irwin, Murray Grossman
2016 Neuropsychologia  
Quantifiers such as many and some are thought to depend in part on the conceptual representation of number knowledge, while object nouns such as cookie and boy appear to depend in part on visual feature knowledge associated with object concepts. Further, number knowledge is associated with a frontal-parietal network while object knowledge is related in part to anterior and ventral portions of the temporal lobe. We examined the cognitive and anatomic basis for the spontaneous speech production
more » ... quantifiers and object nouns in non-aphasic patients with focal neurodegenerative disease associated with corticobasal syndrome (CBS, n=33), behavioral variant frontotemporal degeneration (bvFTD, n=54), and semantic variant primary progressive aphasia (svPPA, n=19). We recorded a semi-structured speech sample elicited from patients and healthy seniors (n=27) during description of the Cookie Theft scene. We observed a dissociation: CBS and bvFTD were significantly impaired in the production of quantifiers but not object nouns, while svPPA were significantly impaired in the production of object nouns but not quantifiers. MRI analysis revealed that quantifier production deficits in CBS and bvFTD were associated with disease in a frontal-parietal network important for number knowledge, while impaired production of object nouns in all patient groups was related to disease in inferior temporal regions important for representations of visual feature knowledge of objects. These findings imply that partially dissociable representations in semantic memory may underlie different segments of the lexicon. Keywords corticobasal degeneration; frontotemporal dementia; speech; language; dementia aphasia; cognitive neuropsychology in dementia Ash et al.
doi:10.1016/j.neuropsychologia.2016.06.013 pmid:27301638 pmcid:PMC4996733 fatcat:xyyqzgk5hbfqfn73zlr5mbzeze