The role of cognition in context-dependent language use: Evidence from Alzheimer's disease

Deixis is a linguistic form that can functionally replace nouns in communication, and it is the most obvious tool to investigate how language is used in relation to communicative context. In this paper, we expand upon our previous study on language use in dementia of the Alzheimer type – DAT [March, E. G., Wales, R., & Pattison, P. (2006). The uses of nouns and deixis in discourse production in Alzheimer's disease. Journal of Neurolinguistics, 19, 311–340], and investigate the role of cognition in deictic use (spatial and person) and noun use across four distinct discourse task conditions. The participants are 26 DAT patients and 26 demographically matched healthy elderly, over the age of 65 years old and of lower education backgrounds. Neuropsychological measures include tests of language, working memory and level of general cognitive functioning. Correlation and regression analyses reveal that the role of cognition is more prominent in the use of spatial deixis than it is in the uses of nouns and person deixis, while the role of working memory is evident even at the noun use level. The findings vary across the four discourse tasks, providing empirical evidence on the role of communicative context in the interplay between language use and cognition.