Session Title: Alzheimer's Disease (AD) including Non-Cognitive Aspects
Presentation Date: Friday, March 14 – Saturday, March 15, 2009
GENERATIVE NAMING AND CATEGORIZATION IN DEMENTIA OF THE ALZHEIMER´S TYPE AND TYPICAL AGING
East Carolina University, Communication Sciences & Disorders, Greenville, United States
Naming failures by individuals with dementia have aided in identifying nature of semantic memory impairments. Naming impairments also are found in healthy older adults. Categorization is a process of concept formation within semantic memory. Categorization studies reveal deterioration in conceptual knowledge in dementia compared to healthy cohorts. Hypotheses: typical older adults may show impairment only in lexical access whereas those with dementia have deficits in earlier concept identification stages of retrieval as well as lexical access.
Fifteen adults with dementia of Alzheimer's type (DAT) and 15 age, education, and gender-matched, typical elderly adults were examined on naming and category concept generation. Participants were native English speakers, literate, with normal hearing.
Experimental tasks: Test of Adolescent/Adult Word Finding (TAWF); category concept generation task (CCGT). CCGT: participants instructed to generate label for 4 category examples of common or goal-directed categories. Context vignettes accompanied half the category examples.
TAWF results: no significant standard score group differences. However: controls performed significantly better than DAT on all subtests than picture naming: nouns and better all subtests than this subtest. DAT group performed significantly worse on category naming than other subtests. CCGT results: 1) controls performed better than DAT participants on goal-directed categories with context; 2) performance was higher for goal-directed categories with context only for controls; and 3) higher performance on common than goal-directed categories without context for controls.
Results support hypotheses relative to lexical access and concept identification for typical aging and DAT. Findings support research that adults with DAT display semantic memory impairments.