Production and comprehension of unaccusatives in aphasia

Background: Recent studies have reported impairments in the production of sentences containing unaccusative verbs (e.g., The ball bounced down the street) in agrammatic patients. In these sentences, the subject is the theme of the verb, resulting in a nonstandard order of thematic roles (often called non-canonical thematic role order). Aims: We tested the hypothesis that aphasic patients would be affected by these features of unaccusatives in both production and comprehension, and that they would show similar deficits in sentences with unaccusative verbs and passive sentences, which also have non-canonical thematic role order. Methods & Procedures: Single-word naming, sentence production, and sentence-picture matching tasks were administered to a group of 9 aphasic participants and 12 age- and education-matched control participants. Outcomes & Results: The aphasic patients performed less well than the controls, and there were effects of the presence of movement in both groups and an interaction between group and sentence type in the sentence production task. Conclusions: These findings support the view that non-canonical thematic role order makes action naming, sentence production, and sentence comprehension more difficult, and that aphasic patients are more affected by the demands of these tasks than controls.