IDEATIONAL AND SEMANTIC CONTRIBUTIONS TO NARRATIVE PRODUCTION IN ADULTS WITH DEMENTIA OF THE ALZHEIMERS TYPE

The narrative production of adults with probable dementia of Alzheimer 's type (DAT) was investigated to determine the extent to which cognit ive or linguistic deficits might explain the breakdown of discourse pr oduction. The structure of narrative tasks was manipulated so that the relationships among task structure and language production correspond ed to predictions about the suspected origin of deficit. Sixteen DAT a nd 16 normal control subjects were administered four narrative tasks t hat were controlled for the amount of content and picture format displ ay. The DAT subjects exhibited reduced content in terms of proposition s and lexical items, shorter sentence lengths with more sentence fragm ents and reference errors. The mode of picture display failed to influ ence the amount of target content, or the grammatical performance of s ubjects. However, when compared to the normal controls, the amount of information pictorially represented significantly influenced the conte nt provided by the DAT subjects; they performed better when the messag e to be related contained relatively less information. These findings support the contributions of both semantic-lexical and ideational syst ems to narrative discourse production. (C) 1997 by Elsevier Science In c.