Verb use in aphasic and non-aphasic personal discourse: What is normal?

Abstract

Sentence and discourse analysis research provides evidence of both impaired and intact ability in verb production in aphasia, based on comparisons made within aphasic subtypes, and between aphasic and control speakers. Comparisons are complicated due to variation in elicitation tasks and genre, participant sample size, and aphasia subtype, as well as methodological differences in determining fluency. In this study, we examined the impact of aphasia on speakers' capacity to talk about their quality of life, applying three analytical methods to 58 speakers' discourse (29 predominantly fluent aphasic speakers; 29 non-aphasic speakers). Both speaker groups produced similar quantity, weight, and type of verbs, with substantial overlap in verb tokens. Relational, material and mental verbs were prevalent. Aphasic speakers had significantly lower predicate argument structure scores, and produced significantly more 0 argument structures, more [Aux + 0] constructions, fewer 1 argument structures in general and fewer 1 argument structures with clausal embedding, compared to non-aphasic speakers. This study provides evidence for intact (semantic weight and type) and impaired (PAS) verb production in aphasia. The heterogeneity within both participant samples challenges assumptions of normality and typicality.