How are inflectional affixes organized in the mental lexicon?: evidence from the investigation of agreement errors in agrammatic aphasics.

Recent psycholinguistic studies have provided evidence that regularly inflected words are decomposed into stems and affixes, both of which have their own representations in the mental lexicon. Specific models of the lexical organization of inflectional affixes have, however, only rarely been investigated in psycho- or neurolinguistic work. We test two recently proposed theoretical models: a representation of affixes (i) in default inheritance trees (Corbett and Fraser, 1993) and (ii) in underspecified paradigms (Wunderlich, 1996). Based on an analysis of agreement errors in elicited speech-production data of German agrammatic aphasics, we argue that affixes are organized with respect to the morphosyntactic features they encode. Specifically, our data indicate that inflectional affixes are best captured within an underspecified paradigm.