SEMANTICS, DISCOURSE MODELS, AND THE RIGHT HEMISPHERE

语篇加工研究的主要目的是明确读者话语表征的性质和构建它们的过程。读者以话语模型的形式呈现文本，文本中的实体(如人、物、地点)和事件以及它们之间的关系的表现。递增地构建话语模型；在由最近文本输入的表示和一般世界知识组成的知识结构的背景下分析输入的语言。文本理解的大部分研究都是为了理解读者如何以及何时获得相关的世界知识，并将这些知识整合到他们的发展中的语篇模式中。相对较少的注意力被投入到理解话语模型是如何被神经实例化的。我们在这个项目中的目标之一是使用心理语言学和语篇加工研究中的标准理论概念和范式来调查右脑在语篇加工中的作用。我们的第二个目标是检验将右脑在话语处理中的作用与其词汇-语义系统的性质联系起来的假设。有一种假说认为，右脑与左脑代表单词的方式不同。右半球比左半球更分散的词汇表征支持遥远相关概念的启动。这些概念支持构建连贯的话语模型所必需的许多推论。第二种假设认为，右脑处理单词的方式与左脑不同。在阐述和重新解释话语模型时，右半球相对于左半球较慢的激活和衰退可能是重要的。右脑在话语加工中的作用将在正常的年轻人、左右半球受损的患者和膝盖骨切开术患者中进行研究。区分这些假说对于理解许多不同的现象具有重要的意义，包括左右半球语义启动的差异以及左右半球损伤引起的理解缺陷的差异。

The primary aim of text processing research is to specify the nature of readers' discourse representations and the processes that construct them. Readers represent a text in the form of a discourse model, a representation of the entities (e.g., people, objects, places) and events in a text and the relations among them. A discourse model is constructed incrementally; incoming language is analyzed against a background of knowledge structures consisting of representations of recent text input and general world knowledge. Much of the research in text comprehension has been aimed at understanding how and when readers access relevant world knowledge and integrate this knowledge into their developing discourse model. Relatively little attention has been devoted to understanding how the discourse model is neurally instantiated. One of our goals in this project is to investigate the right hemisphere's role in discourse processing using the theoretical concepts and paradigms that are standard in psycholinguistic and text-processing research. Our second goal is to examine hypotheses linking the right hemisphere's role in discourse processing to the nature of its lexical-semantic system. One hypothesis suggests that the right hemisphere represents words differently than does the left. More diffuse word representations in the right than in the left hemisphere supports priming of distantly-related concepts. These concepts support many of the inferences that are necessary to construct a coherent discourse model. A second hypothesis suggests that the right hemisphere processes words differently than does the left. Slower activation and decay in the right hemisphere relative to the left may be important in the elaboration and reinterpretation of the discourse model. The right hemisphere's role in discourse processing will be investigated among normal young adults, right- and left- hemisphere lesioned patients, and callosotomy patients. Discriminating between these hypotheses has important implications for understanding a number of disparate phenomena, including differences in semantic priming in the left and right hemispheres and differences in comprehension deficits that arise from left and right hemisphere damage.