Hemispheric contributions to pragmatics

Twenty-seven patients with right-hemisphere damage (RBD) and thirty-one pat ients with left-hemisphere damage (LBD) received a new pragmatics battery i n Hebrew consisting of two parts: (1) comprehension and production of basic speech acts (BSAs), including tests of assertions, questions, requests, an d commands,;md (2) comprehension of implicatures, including implicatures of quantity, quality, relevance, and manner. Each test had a verbal and a non verbal version. Patients also received Hebrew versions of the Western Aphas ia Battery and of the Right Hemisphere Communication Battery. Both LED and RED patients were impaired relative to controls but did nut differ from eac h other in their overall scores on BSAs and on Implicatures when scores wer e corrected by aphasia and neglect indices. There was a systematic localiza tion of BSAs in the left hemisphere: (LH) but not in the right hemisphere ( RH) There was poor localization of Implicatures in either hemisphere rc. In LBD patients, BSAs were associated with language functions measured with t he WAB, suggesting the radical possibility that the classic localization of language functions in aphasia is influenced by the localization of the BSA s required by aphasia language test?;. Both BSAs and implicatures show grea ter functional independence from other pragmatic, language and cognitive fu nctions in the RED than in the LED patients. Thus, the LH is more likely to contain an unmodular domain-nonspecific set of central cognitive mechanism s for applying means-ends rationality principles to intentional activity. ( C) 2000 Academic Press.