Comparing patterns of familiar language use across spontaneous speech contexts in individuals with nonfluent aphasia and healthy controls

Background: It is well-established that individuals with nonfluent aphasia produce proportionally more familiar or non-propositional language than neurotypical adults. Much less is known about the types of familiar language used or about the effects of either language context or impairment on usage patterns. Aims: The purpose of this study was to identify and compare types of familiar language across several spontaneous speech contexts in individuals with and without aphasia in order to refine models of familiar language use for clinical application. Methods & Procedures: Language transcripts from Aphasiabank of 154 individuals with moderate to severe post-stroke Broca’s aphasia and gender- and age-matched controls were coded to identify and classify nine types of familiar language. Language samples included a story-telling task and three conversational topics. Non-parametric comparisons and Spearman’s correlations were used to analyze usage patterns. Outcomes & Results: Individuals with aphasia produced significantly higher proportions of formulaic expressions (context-bound, stereotyped utterances) as compared to controls, but proportions of lexical bundles (connotation-free, multi-word utterances) did not significantly differ. Familiar language usage varied by language contexts and level of severity for individuals with aphasia, whereas production patterns of healthy controls were remarkably stable. Conclusions: This study offers insights into patterns of familiar language usage affected by linguistic ability and language context. A theoretical framework for conceptualising familiar language will result in improvements to existing interventions.