Cognitive Mechanisms and Neural Substrates of Written Language Processing

描述（由申请人提供）：尽管经过了一个多世纪的神经心理学研究，阅读和拼写是否依赖于独立或共同的认知机制和神经基质仍然存在分歧。目前的应用程序旨在提高我们对阅读和拼写在认知和神经解剖学方面的关系的理解。为了实现我们的目标，我们建议对一大批左半球皮质性中风或语义性痴呆患者进行书面和口头语言功能的详细评估，并将行为表现与有关病变位置的精确神经解剖学信息相关联。具体来说，我们计划记录研究参与者的失读症和失写症之间的联系和分离，并阐明导致所识别的不同模式的关键认知和损伤变量。这些观察结果将为测试书面语言处理共享成分模型的主要预测提供经验数据库，根据该模型，正字法、语音和语义表征的损害应该对阅读和拼写产生类似的后果。为了最大限度地提高所提出的病变缺陷研究的可靠性，我们将获得高分辨率MRI扫描，并实施新的病变分析方法，将组织损伤与阅读/拼写表现的相关行为测量相关联。损伤数据也将与语义、语音和视觉/正字法能力的综合测量相关联。此外，我们将使用来自失读症/失写症神经系统患者病变研究和正常人阅读/拼写功能成像研究的聚合证据来识别参与书面语言处理的神经系统，并测试关于不同皮层区域在视觉分析、正字法处理、音韵学和语义学中的作用的具体预测。我们期望这项大规模的调查将产生新的信息，关于影响获得性失读症/失写症患者书面语言表现的认知和损伤变量。我们的预测是，行为和神经解剖学数据将支持阅读和拼写依赖于正字法、音韵学和语义学中心领域内共享的认知表征和神经系统的假设。这些发现应该对书面语言处理的理论模型有重要的启示。

DESCRIPTION (provided by applicant): Despite more than a century of neuropsychological research, there is still disagreement about whether reading and spelling rely on independent or shared cognitive mechanisms and neural substrates. The current application seeks to improve our understanding of the relationship between reading and spelling in both cognitive and neuroanatomical terms. To achieve our objectives, we propose to conduct a detailed evaluation of written and spoken language function in a large group of individuals with left-hemisphere cortical stroke or semantic dementia and correlate behavioral performance with precise neuroanatomical information about lesion location. Specifically, we plan to document both associations and dissociations between the alexia and agraphia profiles of study participants and elucidate the critical cognitive and lesion variables responsible for the different patterns identified. These observations will provide the empirical database for testing the main prediction of shared-component models of written language processing, according to which damage to orthographic, phonological, and semantic representations should have similar consequences for reading and spelling. To maximize the reliability of the proposed lesion-deficit studies, we will obtain high resolution MRI scans and implement novel lesion analysis methods to correlate tissue damage with relevant behavioral measures of reading/spelling performance. Lesion data will also be correlated with composite measures of semantic, phonological, and visual/orthographic ability. In addition, we will use converging evidence from lesion studies in neurological patients with alexia/agraphia and functional imaging studies of reading/spelling in normal individuals to identify the neural systems involved in written language processing and test specific predictions regarding the role of distinct cortical regions in visual analysis, orthographic processing, phonology, and semantics. We expect that this large-scale investigation will produce new information about the cognitive and lesion variables that influence written language performance in individuals with acquired alexia/agraphia. Our prediction is that the behavioral and neuroanatomical data will support the hypothesis that reading and spelling rely on shared cognitive representations and neural systems within the central domains of orthography, phonology, and semantics. These findings should have important implications for theoretical models of written language processing.