ERIC Number: EJ730465
Record Type: Journal
Publication Date: 2004-Oct
Pages: 9
Abstractor: Author
ISBN: N/A
ISSN: ISSN-0278-2626
EISSN: N/A
Verbal Mediation of Number Knowledge: Evidence from Semantic Dementia and Corticobasal Degeneration
Halpern, Casey; Clark, Robin; Moore, Peachie; Antani, Shweta; Colcher, Amy; Grossman, Murray
Brain and Cognition, v56 n1 p107-115 Oct 2004
Patients with corticobasal degeneration (CBD) appear to have impaired number knowledge. We examined the nature of their number deficit while we tested the hypothesis that comprehension of larger numbers depends in part on verbal mediation. We evaluated magnitude judgments and performance on number conservation measures rooted in Piagetian theory in nonaphasic patients with CBD (n=13) and patients with a fluent form of progressive aphasia known as semantic dementia (SD; n=15). We manipulated the numbers of the arrays and the visual-spatial properties of the stimuli being compared during magnitude judgments and Piagetian conservation measures. CBD patients were consistently impaired judging the magnitudes of larger numbers (4-9), while they had minimal difficulty with smaller numbers (magnitudes less than or equal to 3). By comparison, SD patients performed all measures of number knowledge at a ceiling level regardless of number magnitude. Neither patient group was significantly impacted by manipulations of the spatial properties of the stimuli. CBD patients' impairment with larger numbers despite minimal aphasia, and SD patients' intact performance despite an aphasia, challenge the proposal that understanding larger numbers depends on verbal mediation.
Descriptors: Dementia, Stimuli, Semantics, Numbers, Number Concepts, Aphasia, Piagetian Theory, Hypothesis Testing, Comprehension, Brain Hemisphere Functions
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Publication Type: Journal Articles; Reports - Research
Education Level: N/A
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A
Grant or Contract Numbers: N/A