Opposite patterns of hemisphere dominance for early auditory processing of lexical tones and consonants.
In tonal languages such as Mandarin Chinese, a lexical tone carries semantic information and is preferentially processed in the left brain hemisphere of native speakers as revealed by the functional MRI or positron emission tomography studies, which likely measure the temporally aggregated neural events including those at an attentive stage of auditory processing. Here, we demonstrate that early auditory processing of a lexical tone at a preattentive stage is actually lateralized to the right hemisphere. We frequently presented to native Mandarin Chinese speakers a meaningful auditory word with a consonant-vowel structure and infrequently varied either its lexical tone or initial consonant using an odd-ball paradigm to create a contrast resulting in a change in word meaning. The lexical tone contrast evoked a stronger preattentive response, as revealed by whole-head electric recordings of the mismatch negativity, in the right hemisphere than in the left hemisphere, whereas the consonant contrast produced an opposite pattern. Given the distinct acoustic features between a lexical tone and a consonant, this opposite lateralization pattern suggests the dependence of hemisphere dominance mainly on acoustic cues before speech input is mapped into a semantic representation in the processing stream.
Luo
Hao
H
Auditory Research Laboratory, School of Life Sciences, University of Science and Technology of China, Hefei 230027, China.
Ni
Jing-Tian
JT
Li
Zhi-Hao
ZH
Li
Xiao-Ou
XO
Zhang
Da-Ren
DR
Zeng
Fan-Gang
FG
Chen
Lin
L
D000161:Acoustic Stimulation; D044466:Asian People; D003463:Cues; D004292:Dominance, Cerebral / Q000502:physiology*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D007802:Language; D008297:Male; D010775:Photic Stimulation; D012660:Semantics; D013067:Speech Perception / Q000502:physiology*