Reading for Meaning: What Influences Paragraph Understanding in Aphasia?

Purpose: The current study investigated the effect of text variables including length, readability, propositional content, and type of information on the reading comprehension of people with aphasia. Method: The performance of 75 people with aphasia was compared with 87 healthy, age-matched control participants. Reading comprehension was considered in terms of both accuracy in responding to questions tapping comprehension and reading time. Participants with aphasia (PWA) were divided into 2 groups (no reading impairment [PWA:NRI] and reading impairment [PWA:RI]) depending on whether their performance fell within the 5th percentile of control participants. Results: As groups, both PWA:NRI and PWA: RI differed significantly from control participants in terms of reading time and comprehension accuracy. PWA:NRI and PWA:RI differed from each other in terms of accuracy but not reading time. There was no significant effect of readability or propositional density on comprehension accuracy or reading time for any of the groups. There was a significant effect of length on reading time but not on comprehension accuracy. All groups found main ideas easier than details, stated information easier than inferred, and had particular difficulty with questions that required integration of information across paragraphs (gist). Conclusions: Both accuracy of comprehension and reading speed need to be considered when characterizing reading difficulties in people with aphasia.