Williams Joshua T, Darcy Isabelle, Newman Sharlene D
Department of Psychological and Brain Sciences, Indiana University; Program in Cognitive Science, Indiana University, United States; Speech and Hearing Sciences, Indiana University, United States.
Program in Cognitive Science, Indiana University, United States; Second Language Studies, Indiana University, United States.
Brain Res. 2015 Sep 16;1620:107-15. doi: 10.1016/j.brainres.2015.05.014. Epub 2015 May 16.
The present study investigates whether the inferior frontal gyrus is activated for phonetic segmentation of both speech and sign. Early adult second language learners of Spanish and American Sign Language at the very beginning of instruction were tested on their ability to classify lexical items in each language based on their phonetic categories (i.e., initial segments or location parameter, respectively). Conjunction analyses indicated that left-lateralized inferior frontal gyrus (IFG), superior parietal lobule (SPL), and precuneus were activated for both languages. Common activation in the left IFG suggests a modality-independent mechanism for phonetic segmentation. Additionally, common activation in parietal regions suggests spatial preprocessing of audiovisual and manuovisual information for subsequent frontal recoding and mapping. Taken together, we propose that this frontoparietal network is involved in domain-general segmentation of either acoustic or visual signal that is important to novel phonetic segmentation.
本研究调查了在语音和手语的语音分割过程中，额下回是否会被激活。以刚开始学习西班牙语和美国手语的成年早期第二语言学习者为对象，测试他们根据每种语言的语音类别（即分别为初始音段或位置参数）对词汇进行分类的能力。联合分析表明，左侧化的额下回（IFG）、顶上小叶（SPL）和楔前叶在两种语言中均被激活。左侧额下回的共同激活表明存在一种与模态无关的语音分割机制。此外，顶叶区域的共同激活表明，视听和手动视觉信息会进行空间预处理，以便随后进行额叶重新编码和映射。综上所述，我们提出，这个额顶叶网络参与了对声学或视觉信号的通用领域分割，这对于新颖的语音分割很重要。
