SEMANTICS, DISCOURSE MODELS, AND THE RIGHT HEMISPHERE

语篇加工研究的主要目的是明确读者语篇表征的本质及其构建过程。 读者以话语模型的形式表示文本，即实体的表示（例如，人、物、地）和事件以及它们之间的关系。 话语模型是逐步构建的，传入的语言分析的知识结构的背景下，包括最近的文本输入和一般的世界知识的表示。 语篇理解研究的主要目的是了解读者如何以及何时获取相关的世界知识，并将这些知识整合到他们发展的语篇模型中。 相对较少的注意力一直致力于了解话语模型是如何神经实例化。 我们在这个项目中的目标之一是研究右半球的作用，在话语处理中使用的理论概念和范式，是标准的心理语言学和文本处理研究。 我们的第二个目标是检验假设连接右半球的作用，在话语处理的性质，其词汇语义系统。 有一种假说认为，大脑右半球对单词的记忆与左半球不同。在右半球比在左半球更分散的词表征支持启动的远距离相关的概念。 这些概念支持许多推理，这些推理对于构建连贯的话语模式是必要的。 第二种假设认为，右脑处理单词的方式与左脑不同。 相对于左脑，右脑的激活和衰退更慢，这在话语模型的阐述和重新解释中可能很重要。 我们将在正常的年轻人、左右半球损伤的病人和胼胝体切开术病人中研究右半球在话语加工中的作用。区分这些假设对于理解一些不同的现象具有重要意义，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.