Abstract
PURPOSE: To evaluate processing and comprehension of pronouns and reflexives in individuals with agrammatic (Broca's) aphasia and age-matched control participants. Specifically, we evaluate processing and comprehension patterns in terms of a specific hypothesis -- the Intervener Hypothesis - that posits that the difficulty of individuals with agrammatic (Broca's) aphasia results from similarity-based interference caused by the presence of an intervening NP between two elements of a dependency chain. METHODS: We used an eye tracking-while-listening paradigm to investigate real-time processing (Experiment 1) and a sentence-picture matching task to investigate final interpretive comprehension (Experiment 2) of sentences containing proforms in complement phrase and subject relative constructions. RESULTS: Individuals with agrammatic aphasia demonstrated a greater proportion of gazes to the correct referent of reflexives relative to pronouns and significantly greater comprehension accuracy of reflexives relative to pronouns. CONCLUSIONS: These results provide support for the Intervener Hypothesis, previous support for which comes from studies of Wh- questions and unaccusative verbs, and we argue that this account provides an explanation for the deficits of individuals with agrammatic aphasia across a growing set of sentence constructions. The current study extends this hypothesis beyond filler-gap dependencies to referential dependencies and allows us to refine the hypothesis in terms of the structural constraints that meet the description of the Intervener Hypothesis.