German Word Formation and Aphasia*

The goal of this investigation is to show how neuropsychological dissociations in aphasic language disorders can be explained with reference to explicit linguistic theories and how aphasiological data can help to find an optimal linguistic theory supposing, of course, that linguistic theory considers itself part of the study of cognition. Our topic is the interplay of lexical and nonlexical knowledge/processes and the internal structure of the lexicon in grammar and in its aphasic disruption. Our interest in aphasia and in this particular topic suggests the selection of generative grammar as an appropriate frame of reference. To our knowledge, no other linguistic theory that is worked out in sufficient detail makes explicit assumptions about grammar as an object of psychology, e.g. with respect to learnability and modularity. Concerning the place of morphology, it has been rather uncontroversial since Chomsky (1970) that derivational morphology should not interfere with syntactic operations (see however Fabb 1984); on the other ha~d, it remains an issue of controversy whether inflection should be considered part of a lexical word-formation component or part of syntax proper. We will present two German-speaking aphasic patients with a rather rare and remarkable dissociation between a preserved morphophonological lexicon and a disrupted syntax with an almost total loss of semantics. Data from these patients, among other considerations, will be used to support theories of grammar that locate inflectional morphology, together with more "classical" domains of word formation, in the lexicon. The article is organized as follows. In section 1 some remarks are made concerning the relationship between linguistic theory, linguistic processing,