CONSONANT AND VOWEL PRODUCTION OF RIGHT-HEMISPHERE PATIENTS

Recent reports of subclinical phonetic deficits in posterior and most particularly in Wernicke's aphasics have challenged the traditional di chotomy which characterized speech deficits in aphasia as anterior/pho netic and posterisr/phonological. It is unclear whether the basis of t he phonetic deficit in posterior aphasics reflects the fact that the s peech production system extends to more posterior regions of the left hemisphere than previously thought or alternatively is the result of g eneralized brain damage effects. The present study explores the latter possibility by investigating the patterns of speech production in rig ht hemisphere brain-damaged, non-aphasic patients with anterior and po sterior lesions. Acoustic analyses conducted on a range of consonant a nd vowel parameters showed differences between the speech patterns of both anterior and posterior right hemisphere patients and that of Wern icke's aphasics. These findings suggest that the subclinical deficit o f Wernicke's aphasics can not simply be ascribed to a generalized brai n-damage effect and mise the possibility that the right hemisphere als o plays some role, if only a minor one, in the phonetic implementation of speech. (C) 1998 Academic Press.