Syntactic deficits in aphasia and brain modeling of syntactic processing

本研究的目的是通过一系列与语法失语症的损伤-缺陷相关的研究和脑磁图（MEF）等非侵入性脑成像技术来研究大脑中的句法加工。我们发现了以下三个主要结果。首先，语法失语症患者在词性使役句上的表现优于句法性使役句的数据支持了词汇和句法的理论区分。选择限制句和“wh”疑问句的脑磁图研究表明，“wh”运动的神经发生器位于布洛卡区附近，语义处理的神经发生器位于左颞叶下半部分。其次，语法失语症患者在日语长置句和中置句加工中的表现表明，痕迹或移动操作的存在，而不是移动元素与其痕迹之间的距离，是解释句子意义的关键因素。第三，脑磁图研究表明，在乱句中，前额叶皮层和颞顶叶皮层的活动大于规范句，这表明当加工需求增加时，这些区域具有记忆存储功能。在早期的时间范围内，前颞叶皮层也有活动，与句子类型无关，这表明该区域在语法正确的句子中起着句法计算的处理作用。总的来说，这些研究表明，打乱句子的处理是由不同的皮层区域支持的，打乱了短语的原始位置。

The purpose of the present research is to investigate the syntactic processing in the brain through a series lesion-deficit correlational studies with agrammatic aphasics and noninvasive brain imaging techniques such as Magnetoencephalography (MEF). We found the following three main results. First, a theoretical distinction between the lexicon and syntax is supported by the data of agrammatic aphasics' better performance on lexical causatives than the syntactic -sase causatives. An MEG investigation of the processing of sentences with selectional restriction and the wh-interrogatve sentences demonstrates the neural generator of wh-movement, a type of syntactic computation, in the vicinity of Broca's area and that of the semantic processing in the inferior part of the left temporal lobe. Second, agrammatic aphasics' performance on the processing of long- and middle-scrambling sentences in Japanese shows that the existence of a trace, or a movement operation, but not the distance between the moved element and its trace, is a crucial factor in interpreting the meaning of the sentences. Third, an MEG study of scrambled sentences shows that the activities are greater in the scrambled sentences than in the canonical sentences in the prefrontal cortex and the temporo-parietal cortex, suggesting that these areas serve as a memory storage when processing demands increase. Activities are also found in the anterior temporal cortex in the early time range, irrespective of the sentence type, suggesting that this area serves as the processing of syntactic computations in grammatically correct sentences. As a whole, these studies indicate that the processing of scrambled sentences, which has dislocated phrase from its original position, is supported by various cortical areas.