Tone production deficits in nonfluent aphasic Chinese speech.

Previous studies demonstrating a right hemisphere lateralization of musical, tonal, and intonational stimuli had suggested that in aphasic tone language speakers, the tonal phonemes might be subject to a lesser degree of deficit than consonantal phonemes. Using a word repetition task, this research demonstrates that left-damaged nonfluent aphasic speakers of Chinese experience a tonal production deficit which is both quantitatively and qualitatively equivalent to the deficit experienced by these speakers in the production of consonants. It is suggested that in tone languages, lexical specification of tone contour information results in left hemisphere lateralization of that information, thus making the tonal phonemes vulnerable to left hemisphere damage.