| Abstract: | Investigated the organization of semantic memory in patients with Alzheimer's disease (AD) with a triadic comparison task. A multidimensional scaling statistic was used to analyze proximity data and to generate 3-dimensional cognitive maps that were then compared by a discriminant function analysis. Results suggest that the structure of semantic memory in AD Ss differs from that of elderly normal controls (NCs) in 2 ways. First, AD Ss are less consistent in using the attributes (predation, domesticity, and size) of concepts. Second, AD Ss focus primarily on concrete perceptual information (size), whereas NCs stress abstract conceptual knowledge (domesticity). Results are consistent with the notion that AD is characterized by a breakdown in the structure of semantic knowledge. (PsycINFO Database Record (c) 2011 APA, all rights reserved) |
