Speech-like cerebral activity in profoundly deaf people processing signed languages: Implications for the neural basis of human language
Speech-like cerebral activity in profoundly deaf people processing signed languages: Implications for the neural basis of human language
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DOI：
10.1073/pnas.97.25.13961
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发表时间：
2000-12-05
影响因子：
11.1
通讯作者：
Evans, AC
中科院分区：
文献类型：
--
作者：
Petitto, LA;Zatorre, RJ;Evans, AC
一个多世纪以来，我们一直知道大脑的左半球是处理语言的主要场所，但为什么会这样仍然是一个更难捉摸的问题。利用正电子发射断层摄影术，我们报告了在被广泛认为是单峰语音或声音处理区域的关键大脑部位，处理手语特定方面的深度失聪手语者的脑血流活动：当手语者产生有意义的手势时，左下额叶皮质，以及当他们看到手势或手势的无意义部分(手音和音节单位)时，双侧颞叶平面。与普遍的看法相反，临时平面可能并不是专门处理语音声音的，而是专门处理语言所必需的更抽象的属性，这些语言可以使用多种方式。我们假设，参与语言处理的神经组织可能并不完全由感觉通道(如声音)预先指定，而可能涉及对自然语言模式的各个方面进化出独特敏感性的多通道神经组织。这种语言模式方面的神经专门化在神经上似乎是不可改变的，因为具有截然不同的感觉模式的语言(如言语和手势)是在相似的大脑部位加工的，而与此同时，表达和感知自然语言的神经路径似乎在神经上高度可改变。
For more than a century we have understood that our brain's left hemisphere is the primary site for processing language, yet why this is so has remained more elusive. Using positron emission tomography, we report cerebral blood flow activity in profoundly deaf signers processing specific aspects of sign language in key brain sites widely assumed to be unimodal speech or sound processing areas: the left inferior frontal cortex when signers produced meaningful signs, and the planum temporale bilaterally when they viewed signs or meaningless parts of signs (sign-phonetic and syllabic units). Contrary to prevailing wisdom, the planum temporale may not be exclusively dedicated to processing speech sounds, but may be specialized for processing more abstract properties essential to language that can engage multiple modalities. We hypothesize that the neural tissue involved in language processing may not be prespecified exclusively by sensory modality (such as sound) but may entail polymodal neural tissue that has evolved unique sensitivity to aspects of the patterning of natural language. Such neural specialization for aspects of language patterning appears to be neurally unmodifiable in so far as languages with radically different sensory modalities such as speech and sign are processed at similar brain sites, while, at the same time, the neural pathways for expressing and perceiving natural language appear to be neurally highly modifiable.