Cross-modal generalization effects of training noncanonical sentence comprehension and production in agrammatic aphasia

The cross-modal generalization effects of training complex sentence compreh ension and complex sentence production were examined in 4 individuals with agrammatic Broca's aphasia who showed difficulty comprehending and producin g complex, noncanonical sentences. Object-cleft and passive sentences were selected for treatment because the two are linguistically distinct, relying on wh- and NP movement, respectively (Chomsky, 1986). Two participants rec eived comprehension training, and 2 received production training using ling uistic specific treatment (LST). LST takes participants through a series of steps that emphasize the verb and verb argument structure, as well as the linguistic movement required to derive target sentences. A single-subject m ultiple-baseline design across behaviors was used to measure acquisition an d generalization within and across sentence types, as well as cross-modal g eneralization (i.e., From comprehension to production and vice versa) and g eneralization to discourse. Results indicated that both treatment methods w ere effective for training comprehension and production of target sentences and that comprehension treatment resulted in generalization to spoken and written sentence production. Sentence production treatment generalized to w ritten sentence production only; generalization to comprehension did not oc cur. Across sentence types generalization also did not occur, as predicted, and the effects of treatment on discourse were inconsistent across partici pants. These data are discussed with regard to models of normal sentence co mprehension and production.