THE ORIGINS OF FORMAL PARAPHASIAS IN APHASICS PICTURE NAMING

Accounts of spoken word production differ on whether aphasics' formal paraphasias derive solely from se,omental distortion or whether some d erive instead from whole word substitution. Form-related paraphasias p roduced by nine aphasics during picture naming were examined for evide nce of lexical effects (word, frequency, and grammatical class biases) and for the manner in which target phonemes and word shape were prese rved. Preservation patterns were consistent with previous descriptions of aphasic and nonaphasic form-related speech errors. Evidence for wo rd and frequency biases was found, as well as a grammatical class bias sensitive to the degree of target-response segmental overlap. In conj unction, the results indicate that formal paraphasias arise, at least in part, via word substitution. The findings are supportive of interac tive models with phonological-to-lemma feedback and/or modular models with a grammatically organized lexeme level. (C) 1997 Academic Press.