Communicative function in patients with questionable Alzheimer's disease.

The communicative skills of patients with questionable Alzheimer's disease (AD) were examined by having patients describe events shown in a silent video cartoon. As anticipated, questionable AD patients provided fewer clauses in their descriptions than did education- and age-matched controls. This finding was independent of differences in word finding ability. More important, the patients failed to describe as many of the thematically important events as did the controls, a difference that affected the overall informativeness of the communication. Even though the patients were sensitive to event importance, there was no evidence of compensation in their descriptions (i.e., a greater concentration of important events). Several interpretations are presented that focus on possible deficits in the pragmatic or semantic systems of language or both as an early symptom of Alzheimer's disease.