LEXICAL TONE DISRUPTION IN CANTONESE APHASIC SPEAKERS

This study reports on the nature of tonal disruption in brain-damaged subjects. The language selected for investigation was Cantonese, a Chinese dialect spoken in southern China and Hong Kong with six lexical tones. Brain-damaged subjects were asked to identify and produce Cantonese words in isolation. It was found that lexical tone disruption is a generalized sign in aphasia. There was no evidence that there exists a particular pattern of tonal disruption in any specific type of aphasia. Results also indicated tonal disruption in both production and perception tasks. This impairment was often more severe with the perceptual ability than the production. Indeed, the data suggested that tonal disruption can be a disorder at either the phonological or phonetic level.