Alzheimer’s disease: cognition and picture-based narrative discourse

Purpose to investigate discourse in Alzheimer’s disease (AD) using a picture narrative task; to examine possible difficulties in the expression of knowledge and the relationship between discourse and cognition. Methods the design of the study was transversal, using quantitative comparison of groups. The clinical sample consisted of eighteen subjects with AD, eight of them with moderate cognitive decline (GDS 4) and ten with moderate-severe cognitive decline (GDS 5); the control group consisted of sixteen subjects without neurological or psychiatric disorders. All were matched for gender, native language, age and education and subjects underwent cognitive assessments. The discourse task consisted of a picture narrative of the tale “Little Red Riding Hood.” Results participants with AD had lower overall coherence scores and more difficulties in the expression of knowledge than subjects without AD. Discourse deficits correlated with performance on cognitive measures. The GDS 4 and GDS 5 groups differed in local coherence scores. Conclusion discourse of subjects with AD was characterized by failure in coherence and informativeness, which related strongly with their cognitive deficits.