Conjoint and extended neural networks for the computation of speech codes: The neural basis of selective impairment in reading words and pseudowords
Conjoint and extended neural networks for the computation of speech codes: The neural basis of selective impairment in reading words and pseudowords
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DOI：
10.1093/cercor/11.3.267
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发表时间：
2001-03-01
期刊：
影响因子：
3.7
通讯作者：
Theodore, W
中科院分区：
文献类型：
--
作者：
Xu, B;Grafman, J;Theodore, W
语音代码（即语音）的计算是单词阅读的一个重要方面。了解语音过程背后的神经系统和机制为研究大脑中的语言提供了基础。我们使用高分辨率三维正电子发射断层扫描（PET）来研究语音过程所必需的神经系统。语音代码的计算上的神经活动的负担被最大化的三个押韵任务（押韵的话，伪词和字打印在混合字母的情况下）。与这些任务相关的大脑激活模式与涉及视觉特征检测的两个基线任务进行了比较。结果表明，强大的左侧震中的神经活动的押韵不分性别。单词押韵激活了参与假词押韵的相同大脑区域，这表明联合神经网络用于单词和假词的语音处理。然而，假词押韵引起的脑血流量的变化最大，激活更多的体素在左后前额叶区和左下枕颞交界处。此外，假词韵激活左侧缘上回，这是不明显的词韵。这些结果表明，押韵的假词需要积极参与的扩展神经系统和网络没有观察到的押韵的话，理论和模型的视觉词阅读和选择性阅读功能障碍的脑损伤后的结果进行了讨论。
The computation of speech codes (i.e, phonology) is an important aspect of word reading. Understanding the neural systems and mechanisms underlying phonological processes provides a foundation for the investigation of language in the brain. We used high-resolution three-dimensional positron emission tomography (PET) to investigate neural systems essential for phonological processes. The burden of neural activities on the computation of speech codes was maximized by three rhyming tasks (rhyming words, pseudowords and words printed in mixed letter cases). Brain activation patterns associated with these tasks were compared with those of two baseline tasks involving visual feature detection. Results suggest strong left lateralized epicenters of neural activity in rhyming irrespective of gender. Word rhyming activated the same brain regions engaged in pseudoword rhyming, suggesting conjoint neural networks for phonological processing of words and pseudowords. However, pseudoword rhyming induced the largest change in cerebral blood flow and activated more voxels in the left posterior prefrontal regions and the left inferior occipital-temporal junction. In addition, pseudoword rhyming activated the left supramarginal gyrus, which was not apparent in word rhyming. These results suggest that rhyming pseudowords requires active participation of extended neural systems and networks not observed for rhyming words, The implications of the results on theories and models of visual word reading and on selective reading dysfunctions after brain lesions are discussed.