Coherence violations and propositional usage in the narratives of fluent aphasics.

Aphasic patients have been generally assumed to produce coherent narratives, despite their numerous surface structure deficits. The current study is designed to analyze three types of coherence violations (i.e., information gaps, repetitions of propositions, and irrelevant propositions) in the narratives of mildly impaired conduction, anomic, and Wernicke's aphasics. Results reveal that the three aphasic groups produce qualitatively different patterns of coherence violations. It is hypothesized that these coherence violations reflect adaptive strategies used by the aphasic patients to compensate for their underlying impairments. While the anomic and conduction aphasics appear to compensate for surface structure deficits, the Wernicke's aphasics seem to have an underlying coherence deficit.