This study deals with a multidimensional analysis of language attrition in normal aging and in Alzheimer’s disease. A comparative analysis of spontaneous speech was conducted through three linguistic levels : 1) the phonetic-phonological level ; 2) the lexical-semantic level ; 3) the syntactic level. Our results show that the discourse produced by Alzheimer patients differs significantly from that produced by healthy elderly by a more disfluent speech, a significant reduction of the vocabulary diversity and discourse informativeness, and finally, by a remarkable reduction in syntactic complexity. Our results contribute to understand better the linguistic profile of Alzheimer’s patients. We show that a better understanding of language disorders associated with this pathology may contribute in a meaningful way to improve early and / or differential diagnosis of Alzheimer’s disease. In term of application, the goal of this research is to develop a language assessment tool adapted to the demented elderly. Through this work we hope to have contributed to the further development of speech therapy (i.e. non-pharmacological treatment) useful for the maintenance or improvement of the communicative capacity of patients suffering from Alzheimer’ disease.
