Cohesion in the discourse of people with post-stroke aphasia

Aphasic discourse has been investigated through two major approaches: a micro-linguistic approach and a macro one, but the separate analysis of the micro and macro aspects of aphasic discourse has led to a noticeable gap between them. Cohesion analysis is one of the possible ways that can directly connect these two aspects. However, few studies have investigated cohesion in aphasic discourse in an integrated manner. The present study employs a mixed-methods approach to examine whether and how patients with fluent and non-fluent stroke-induced aphasia differ from normal individuals in the cohesion of their discourse, aiming to provide a more comprehensive understanding of this issue. We compared the use of cohesive devices in the discourse of 7 non-fluent aphasics (4 males, mean age = 70.9) and 9 fluent aphasics (4 males, mean age = 70.7) against 16 non-aphasic controls (NACs) (8 males, mean age = 71.0). Transcripts were analysed and conclusions were drawn based on the combination of quantitative and qualitative observations. As predicted, discourse by aphasic participants is less cohesive than that by non-aphasic participants and the three groups' discourse differs from each other in the distribution of cohesion categories, with non-fluent aphasics having more trouble in using grammatical cohesive devices while fluent aphasics more severely affected in constructing lexical cohesion. Results suggest that cohesion in post-stroke aphasic discourse may vary between different aphasia types and thus can be rather complicated. Additional work involving more aphasia types and more dimensions of discourse cohesion is needed to provide further insight into this question.