Inter-individual variability in discourse informativeness in elderly populations
Abstract
An increasing number of studies focus on discourse production in patients with neurodegenerative diseases and underline its clinical usefulness. However, if this is to be used as a clinical tool, one needs to consider how normal discourse varies within cognitively unim- paired elderly populations. In the current study, the aim has been to investigate discourse macrolinguistic variability. For this, 123 par- ticipants aged between 55 and 84 were recruited. A cluster analysis of their discourse macrolinguistic features was conducted. Then, cluster characterisation based on socio-demographic and linguistic performance was tested (fluency, naming, syntax and spelling). This method aims to identify various profiles of speaker and informative- ness and then see if inter-individual variability may be related to socio-demographic and/or linguistic aspects. Four clusters of informa- tiveness were found but no socio-demographic features appeared significant. The fourth cluster, defined as ‘off topic’, had lower per- formance during linguistic tasks than others and thus the boundary between normality and pathology should be questioned.