SENTENCE COMPREHENSION DEFICITS IN ALZHEIMERS-DISEASE - A COMPARISON OF OFF-LINE VS. ONLINE SENTENCE PROCESSING

Two studies explored whether sentence comprehension impairments in Alz heimer's disease (AD) are due to deficits in syntactic processing or m emory. Study 1 used a picture-pointing sentence comprehension task to measure the final outcome of comprehension in an off-line fashion. It showed the comprehension of 30 patients with AD to be impaired, but su ggested that the deficits could not be attributed solely to syntactic impairments. Study 2 investigated the effects of memory on sentence co mprehension by comparing off-line (grammaticality judgment) with on-li ne (cross-modal naming) language processing in 11 AD and 9 control sub jects. The results revealed impaired performance in the off-line task but normal performance in the on-line task using the same sentences. P erformance on the off-line task correlated with independent measures o f verbal working memory. These data are used to argue that sentence co mprehension impairments are related to verbal working memory deficits in AD. (C) 1998 Academic Press.