Hemispheric specialization in auditory processing of Chinese lexical tones: a study using whole-head recordings of EEG

It has long been established that the left hemisphere is specialized for speech whereas the right for music. However, it remains elusive whether the labor division between the two hemispheres is determined by function or acoustic property of stimuli. The confusion in the literature raises a possibility that the two factors are involved at different levels of auditory perception, respectively. In the present study, we demonstrate the dependence of hemisphere specialization on acoustic properties of stimulus in early auditory processing. We frequently presented to Mandarin Chinese speakers a meaningful consonant-vowel syllable and infrequently varied either its lexical tone or initial consonant to result in changes in word meaning. The lexical tone contrasts evoked a stronger pre-attentive electric response, as revealed by whole-head recordings of the mismatch negativity, in the right hemisphere than in the left but the consonant contrasts produced an opposite pattern. This hemisphere dominance was acoustic...