Interdisciplinary Program in Cognitive Science, Seoul National University, Republic of Korea.
Brain Lang. 2012 Jul;122(1):1-10. doi: 10.1016/j.bandl.2012.04.011. Epub 2012 May 24.
Speech production is inextricably linked to speech perception, yet they are usually investigated in isolation. In this study, we employed a verbal-repetition task to identify the neural substrates of speech processing with two ends active simultaneously using functional MRI. Subjects verbally repeated auditory stimuli containing an ambiguous vowel sound that could be perceived as either a word or a pseudoword depending on the interpretation of the vowel. We found verbal repetition commonly activated the audition-articulation interface bilaterally at Sylvian fissures and superior temporal sulci. Contrasting word-versus-pseudoword trials revealed neural activities unique to word repetition in the left posterior middle temporal areas and activities unique to pseudoword repetition in the left inferior frontal gyrus. These findings imply that the tasks are carried out using different speech codes: an articulation-based code of pseudowords and an acoustic-phonetic code of words. It also supports the dual-stream model and imitative learning of vocabulary.
言语产生与言语感知密不可分，但通常是分开研究的。在这项研究中，我们使用了一种口头重复任务，使用功能磁共振成像同时激活两个端点来识别言语处理的神经基础。被试口头重复包含一个模糊元音的听觉刺激，这个元音可以被理解为一个单词或一个假单词，这取决于元音的解释。我们发现，口头重复通常会在大脑外侧裂和颞上回的双侧激活听觉-发音界面。对比单词与假单词的试验结果揭示了左后颞叶中部区域的单词重复所特有的神经活动，以及左额下回的假单词重复所特有的神经活动。这些发现表明，这些任务使用了不同的言语代码：基于发音的假单词代码和基于声学-语音的单词代码。它也支持词汇的双重流模型和模仿学习。
