Discourse topic management in senile dementia of the Alzheimer's type.

The purpose of the study was to provide a detailed evaluation of the topic management abilities of a group of subjects with senile dementia of the Alzheimer's type (SDAT) and to compare their patterns of topic management to that of a normal elderly (NE) subject group. Twenty-four subjects participated in the study: 12 SDAT subjects and 12 NE subjects matched along the variables of age, sex, and education. The evaluation of topic management was based on a 20-minute casual conversational interaction between the subject and a speech-language pathologist that was videotaped and later transcribed orthographically. Topic management was analyzed in terms of a modified version of the multidimensional topic coherence analysis developed by Mentis and Prutting (1991). The results indicated significant differences between the SDAT and NE subjects along a number of parameters of topic introduction and maintenance. The topic management profiles of the SDAT subjects were characterized by a reduced ability to change topics while preserving the discourse flow, difficulty in actively contributing to the propositional development of the topic, and a failure to consistently maintain topic in a clear and coherent manner. These problems appeared to be related to underlying problems across the discourse-pragmatic, linguistic, and cognitive domains; they highlight the need to more fully explore the interactions among deficits in SDAT and their effects on conversational discourse.