Linguistic markers of story recall can help differentiate mild cognitive impairment from normal aging

Abstract

Mild cognitive impairment (MCI) involves a decline in episodic memory and, in many cases, language. Taler et al. (2021) developed a set of story recall materials that we expected to be sensitive to changes in language in normal aging and MCI. Here, we examined the lexical (word-level) contents of participants’ story recall responses from Taler et al. (2021). First, we compared the lexical features of story recall responses between young adults (YA; n = 22), healthy older adults (OA; n = 38), and people with MCI (n = 17) using the Linguistic Inquiry and Word Count (LIWC) program. Second, we explored the associations between these linguistic variables and story recall in each group. People with MCI produced fewer words overall, as well as higher proportions of verbs and pronouns on immediate recall compared to both YAs and OAs. OAs also produced higher proportions of auxiliary verbs than YAs. Story recall scores were positively correlated with total word count in YA and MCI groups. In YAs only, adjectives were positively correlated with recall. In OAs, recall scores were negatively correlated with proportion of verbs. Our results suggest that the LIWC program paired with our novel story recall task may help identify linguistic markers of normal aging and MCI. Some aspects of language use during story recall may also be related to episodic memory in cognitively healthy individuals and people with MCI. Our findings may have implications for the optimization of MCI screening tools to detect changes in language.