Cognitive Mechanisms and Neural Substrates of Written Language Processing

描述(申请人提供)：尽管神经心理学研究已经进行了一个多世纪，但对于阅读和拼写是依赖于独立的还是共享的认知机制和神经基础，仍然存在分歧。目前的应用程序试图从认知和神经解剖学的角度来提高我们对阅读和拼写之间关系的理解。为了实现我们的目标，我们建议对一大群患有左半球皮质卒中或语义性痴呆的人进行详细的书面和口语语言功能评估，并将行为表现与关于病变位置的准确神经解剖学信息相关联。具体地说，我们计划记录研究参与者失写和失写特征之间的联系和分离，并阐明导致不同模式的关键认知和损害变量。这些观察将为检验书面语言加工的共享成分模型的主要预测提供经验数据库，根据该模型，拼写、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拟议的病变缺失研究的可靠性，我们将获得高分辨率的MRI扫描，并实施新的病变分析方法，将组织损伤与相关的阅读/拼写行为测量相关联。病变数据还将与语义、语音和视觉/正字法能力的综合测量相关联。此外，我们将使用神经系统失写/失写患者的病变研究和正常人阅读/拼写的功能成像研究的融合证据，以确定参与书面语言处理的神经系统，并测试关于不同皮质区域在视觉分析、拼写处理、音系学和语义中的作用的特定预测。我们期望这项大规模的调查能为影响后天失读症/失写症患者书面语言表现的认知和损害变量提供新的信息。我们的预测是，行为和神经解剖学数据将支持这样的假设，即阅读和拼写依赖于正字法、音系学和语义学中心领域中的共享认知表征和神经系统。这些发现对书面语加工的理论模型具有重要的启示意义。

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.