Selective difficulties with spoken nouns and written verbs: A single case study

We describe an individual who exhibits greater difficulties in speaking nouns than verbs and greater difficulties in writing verbs than nouns across a range of both single word and sentence production tasks. This double dissociation of grammatical category by modality within a single individual represents an important challenge to the claim that all apparent category grammatical deficits can be reduced to the effects of the various semantic variables. The modality-specific nature of the findings clearly support the representation of grammatical category distinctions at post-semantic levels of representations and processing and they raise a number of questions regarding the specific instantiation of these distinctions within current theoretical frameworks of language production. (C) 2002 Elsevier Science Ltd. All rights reserved.