In studying the relationship between brain and language aphasiologists hope that the patterns of dissociation observed in different aphasic syndromes represent some decomposition of a universal language processing system. However, because most research is based on English, there is a confound between universal processes and language-specific content. In our first funding project, we have given existing theories of grammatical breakdown in aphasia a rigorous cross-linguistic test. Our results suggest that agrammatism, paragrammatism and anomia all take very different forms across typologically-distinct languages. However, we also find evidence that grammatical morphology is selectively vulnerable to brain damage across languages--not only in Broca's aphasia, but in every class of patients studied to date. We now propose a comprehensive cross-linguistic study of grammatical processing in three forms of aphasia (Broca's aphasia, Wernicke's aphasia, and anomia), across languages that vary widely in the nature and richness of their morphological systems (i.e. English, Italian, Hungarian, Serbo-Croatian, German, Hindi, Turkish and Chinese). To unconfound effects of language task and syndrome, we will study lexical/morphological processing across a broad array of tasks: receptive vs. expressive language, focusing either on form (e.g. grammaticality judgments) or meaning (e.g. comprehension), in contexts of varying size (e.g. word-suffix, phrases, sentences), in either the visual or the auditory modality, """"""""on-line"""""""" and """"""""off-line"""""""". The research is based on 12 years of cross-linguistic research with normals, and on a lexicalist theory of grammatical processing designed to account for variations in language and in processing capacity. Within this framework, we want to know why morphology is selectively vulnerable in aphasia, and whether there are qualitative differences in the causes of lexical/morphological breakdown across syndromes. Results will contribute not only to our understanding about the plasticity of brain-language relations, but also to international communications about aphasia, and to the establishment of language batteries tailored to the particular structures of different native languages. We will also establish the first computerized archive of speech production data from aphasic patients in different language groups.
