Analysis of brain activities and investigation of hierarchical language processing

大脑活动分析和分层语言处理研究

基本信息

批准号：
15300148
负责人：
KURIKI Shinya
金额：
$ 10.05万
依托单位：
Hokkaido University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2005
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-15300148/
关键词：
Magnetoencephalography Language Inverse problem Grammar Noninvasive measurement Imaging Syntax processing MEG(脳磁図)

项目摘要

The research is aimed at elucidating spatiotemporal neural activities during sentence reading. To analyze multiple activities within the brain, minimum L1 norm reconstruction was examined by simulation. It was found that the locating accuracy was within about 5 mm when a gravitational center of estimated dipole sources was computed, where the standard error was about 15 mm. The dipole moments, which were estimated for multiple subjects, were averaged by using Gaussian function with the above standard error in standard brain coordinates, which enabled visualization of distributed brain activities.In MEG measurements we used Japanese complex sentences that included a main clause, in a canonical phrase-order of subject (S) - object (O) -verb (V), combined with a subordinate clause. Sentences that had the main clause of scrambled O-S-V phrases were also composed and mixed. Those sentences were presented visually phrase-to-phrase to subjects. They performed a judgment task during MEG record … More ing, answering a question given in canonical-order phrases about the thematic role, i.e., "who did whom what" of the main clause. MEG responses of different phrases in the main clause were averaged, from which distributed current sources were estimated by L1 norm method.Grand mean distribution across eleven subjects of the localized sources showed regional activities focused in the prefrontal and posterior temporal areas in the left hemisphere, which may overlap with classical language areas. Activities were also found around the left central sulcus, indicating sensory/motor cortices, centered at the hand area. These active regions, together with visual occipital cortices were observed in most subjects, though large inter-subject varialbilities existed in the magnitude and extent of the activities. Posterior part of the prefrontal area and the sensory/motor areas were more active for scrambled than canonical sentences. No focal activities in the central and prefrontal regions were observed in the right hemisphere. Less

该研究旨在阐明句子阅读过程中的时空神经活动，通过模拟检查最小 L1 范数重建，发现当估计偶极源的重心时，定位精度在 5 毫米左右。计算出的标准误差约为 15 毫米，通过使用高斯函数与标准大脑坐标中的上述标准误差进行平均，从而实现了对多个受试者的偶极矩的可视化。在 MEG 测量中，我们使用日语复杂句子，其中包括一个主语从句，采用主语 (S) - 宾语 (O) - 动词 (V) 的规范短语顺序，并结合具有从句的从句。打乱的 O-S-V 短语的主句也被组合和混合，这些句子以短语到短语的形式直观地呈现给受试者，他们在 MEG 记录过程中执行了一项判断任务，回答了有关规范顺序短语的问题。主题角色，即主句中不同短语的 MEG 响应被平均，通过 L1 范数方法估计分布的当前源。本地化源的 11 个主题的总体平均分布。显示区域活动集中在左半球的前额叶和后颞区，这可能与古典语言区域重叠，在左中央沟周围也发现了活动，表明以手为中心的感觉/运动皮层。大多数受试者都观察到这些活跃区域以及视觉枕叶皮质，但前额叶区域的后部和感觉/运动区域的活动幅度和范围存在较大的受试者间差异。右半球的中央和前额叶区域没有观察到焦点活动。