An assessment of the relation between narrative productivity, subjectivity expression, emotion description, and ToM abilities in healthy aging

Narrative discourse production is among the most important aspects of human communication. This study focuses on the impact of healthy aging on three major aspects of narrative production: productivity skills (in terms of words produced, speech rate, and % of informative words), the use of subjectivity markers (i.e., in our study those adjectives and adverbs that signal the narrator's personal stance, emotions, evaluations, or perspective), and the spontaneous tendency to describe emotions during storytelling. We also investigated the relationship between these three features of narrative production and Theory of Mind skills within the context of the effects of healthy aging on these measures. Ninety participants were divided into three age groups: young adults, older adults, and senior-old adults. Their speech samples were analyzed using a multilevel discourse analysis. Among subjectivity markers, older adults produced more modalizers (i.e., adjective and adverbs reflecting the speaker's evaluation about the degree of certainty or doubt of what is being told) than younger participants. In contrast, the use of emotion descriptors significantly dropped in senior-old adults. Furthermore, performance on Theory of Mind tasks correlated with the spontaneous tendency to describe emotions and produce informative words during storytelling but not with the production of subjectivity markers.