The bilingual brain: bilingual aphasia.

Since most people in the world know more than one language, bilingual aphasia is an important line of research in clinical and theoretical neurolinguistics. From a clinical and ethical viewpoint, it is no longer acceptable that bilingual aphasics be assessed in only one of the languages they know. Bilingual aphasic patients should receive comparable language tests in all their languages. In the present work, language recovery of 20 bilingual Friulian-Italian aphasics was investigated. Thirteen patients (65%) showed a similar impairment in both languages (parallel recovery), four patients (20%) showed a greater impairment of L2, while three patients (15%) showed a greater impairment of L1. Despite the many hypotheses advanced to account for nonparallel recovery, none of them seems to provide satisfactory explanations. The study of bilingual aphasics with parallel impairment of both languages allows us to verify the hypothesis whereby grammatical disorders in aphasia depend on the specific structure of each language. As far as rehabilitation programs for multilingual aphasics are concerned, several questions have been raised, many of which still need a satisfactory answer.