Neural Bases of Semantic Interpretation

尽管我们对语义解释的大脑基础的理解开始在单个词汇项目的水平上得到详细的阐述，但构成复杂意义的神经机制仍然完全未知。在国家科学基金会的支持下，Pylkkanen博士将进行一项为期三年的调查，旨在阐明复杂意义构成的时空动态。脑活动将通过脑磁图（MEG）来测量，它提供了目前可用的认知神经科学方法中空间和时间分辨率的最佳组合。人类语言最令人着迷的特点之一是，许多意思都不明显地表达出来。例如，当遇到“男孩把门关得很紧”这样的句子时，所有说英语的人都会立即自动地知道这个句子描述了关闭事件和紧闭状态之间的因果关系，尽管这个句子中没有明显的元素描述因果关系。此外，所有说话者都一致认为，紧绷状态并不适用于明确提到的门，而是适用于门与门框之间某种未被提及的闭合。该项目侧重于隐性意义的解释，因为它提供了一个独特的机会来研究语义组成，同时在很大程度上消除了语音和句法处理。该项目涵盖了表征复杂性的多个层面，涉及三组研究：一组研究看似简单的单个词汇项目的隐性复杂性，另一组研究语义不透明在处理明显复杂的单词（如“sweat-er”）中的影响，第三组研究句子层面的隐性意义构成。该项目代表了认知神经科学方法论与理论语言学中出现的详细表征假设的一种新型结合，反映了Pylkkanen博士在这两个领域的综合训练。这项研究的一个组成部分是汇集了来自语言学、心理学、医学和/或神经科学背景的不同群体的学生和教师。最后，该项目的临床应用潜力巨大。语义障碍是大量神经系统疾病的特征，包括失语症、精神分裂症、发育障碍（如自闭症）和神经退行性疾病。理解语义障碍的一个先决条件是首先理解健康的大脑是如何获取和计算意义的。

Although our understanding of the brain bases of semantic interpretation is beginning to be detailed at the level of individual lexical items, the neural mechanisms by which complex meanings are composed are still entirely unknown. With National Science Foundation support, Dr. Pylkkanen will conduct a three-year investigation aimed at elucidating the spatio-temporal dynamics of complex meaning composition. Brain activity will be measured with magnetoencephalography (MEG), which offers the best combination of spatial and temporal resolution of currently available cognitive neuroscience methods. One of the most fascinating features of human language is that many meanings are not expressed overtly. For example, when a sentence such as "the boy shut the door tight" is encountered, all English speakers immediately and automatically know that this sentence describes a causal relation between an event of shutting and a state of tightness even though no overt element in the sentence describes causality. Further, all speakers converge on the interpretation that the state of tightness does not hold of the explicitly mentioned door, but rather of some unmentioned closure between the door and its frame. This project focuses on the interpretation of covert meaning, as it offers a unique opportunity to study semantic composition while largely eliminating phonological and syntactic processing. The project covers multiple levels of representational complexity and involves three sets of studies: one investigating covert complexity in individual lexical items that appear to be simple, another on the effect of semantic opacity in the processing of overtly complex words such as "sweat-er", and a third on covert meaning composition at the sentence level. The project represents a novel type of combination of cognitive neuroscience methodology with detailed representational hypotheses emerging from theoretical linguistics, reflecting Dr. Pylkkanen's combined training in the two fields. An integral part of this research is bringing together a diverse group of students and faculty from linguistics, psychology and medical and/or neuroscience backgrounds. Finally, the clinical applications of the project are potentially substantial. Semantic impairment characterizes a vast array of neurological disorders, including aphasias, schizophrenia, developmental disorders such as autism, and neurodegenerative diseases. A prerequisite for understanding semantic malfunction is first understanding how the healthy brain accesses and computes meaning.