THE USE OF SEMANTIC KNOWLEDGE IN ALZHEIMERS-DISEASE - EVIDENCE FOR IMPAIRMENTS OF ATTENTION

The ability to access and use semantic knowledge was examined in 25 patients with Alzheimer's disease (AD) and 31 healthy controls. The AD patients exhibited intact automatic activation of semantic relationships on a semantic priming task. They also made active use of category information on a recognition memory test. However, the patients did not use semantic information to generate expectations on the semantic priming task and were inconsistent in their use of category information on the memory test. It is suggested that attentional deficits underlie the observed impairments and may in fact help explain the patterns of performance across tasks differing widely in their overt cognitive demands.