Opposite patterns of hemisphere dominance for early auditory processing of lexical tones and consonants
Opposite patterns of hemisphere dominance for early auditory processing of lexical tones and consonants
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DOI：
10.1073/pnas.0607065104
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发表时间：
2006-12-19
影响因子：
11.1
通讯作者：
Chen, Lin
中科院分区：
文献类型：
--
作者：
Luo, Hao;Ni, Jing-Tian;Chen, Lin
功能性核磁共振成像（MRI）或正电子发射断层扫描（positron emission tomography）研究显示，在普通话等声调语言中，词汇音调携带语义信息，并优先在母语者的左脑半球处理，这可能测量了包括听觉处理注意阶段的神经事件在内的暂时聚集的神经事件。在这里，我们证明了在注意力集中前阶段，词汇音调的早期听觉处理实际上是侧化到右半球的。我们经常向以普通话为母语的人展示一个有意义的听觉词，这个词有辅音和元音的结构，并且很少改变它的词汇语调或初始辅音，使用一个古怪的范式来形成对比，从而导致词义的变化。通过对不匹配负性的全脑电记录显示，词汇音调对比在右半球诱发了更强的前注意反应，而辅音对比则产生了相反的模式。考虑到词汇语调和辅音之间不同的声学特征，这种相反的侧化模式表明，在语音输入在处理流中被映射为语义表示之前，半球优势主要依赖于声学线索。
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.