CROSS-SECTIONAL ANALYSIS OF ALZHEIMER-DISEASE EFFECTS ON ORAL DISCOURSE IN A PICTURE DESCRIPTION TASK

To examine the relation of dementia severity to the quality and quanti ty of oral discourse of individuals with Alzheimer disease (AD), a pic ture description task was administered to elicit oral discourse sample s from 63 AD subjects, five individuals with very mild cognitive impai rment, and 52 normal controls. Eight measures of discourse were used: total words, information units, conciseness, circumlocutions, frustrat ions, aborted phrases, revisions, and ideational repetitions. Informat ion units, which decreased with increased dementia severity, proved to be the best measure for evaluating the effects of AD on oral descript ive discourse. The conciseness index also decreased with increased dem entia severity, and a significantly greater proportion of AD discourse samples contained ideational repetitions. Circumlocutions and frustra tions rarely occurred, and although the discourse of AD subjects was m ore likely to contain an aborted phrase, the frequency of aborted phra ses did not vary by stage of dementia. Revisions were commonly observe d in the discourse of both normal controls and AD subjects and did not differentiate the two groups.