The Semantic Network and Functional Compromise.

摘要

Semantic network breakdown has been posited to be related to the progressive declines observed in Alzheimer's disease (AD) and its prodromes. While the relationship between semantic memory and AD has been established, the relationship between semantic memory and instrumental activities of daily living (IADL) is less clear. The current study was designed to elucidate this relationship by examining a semantic clustering index on the California Verbal Learning Test, Second Edition (CVLT-II) and the measure's ability to predict functional compromise of healthy older participants and those with Alzheimer's disease or Mild Cognitive Impairment (MCI) on two measures of IADLs---the Everyday Cognition Scale (ECog) and the Functional Activities Questionnaire (FAQ). The results revealed that semantic clustering performance differentiated between AD, amnestic MCI, and normal control participants. The FAQ distinguished between AD and non-AD participants, while the ECog differentiated between AD, amnestic MCI, and normal controls. When considering all diagnostic groups, semantic clustering was predictive of instrumental ADL functioning as measured by the ECog and FAQ, but the addition of an executive functioning covariate (Trails B) significantly improved the predictive models. In excluding the AD group from the analysis, semantic clustering was predictive of instrumental ADL functioning as measured by the FAQ beyond that of Trails B. In excluding the AD group, semantic clustering was not predictive of instrumental ADL functioning as measured by the ECog.