Neural correlates of orthographic and phonological processing in dyslexia

描述(由申请人提供)：建议的工作旨在更好地了解语言处理的发展时间进程，特别是在无声阅读过程中的拼写和语音文字处理。本项目的最终目标是进一步阐明阅读障碍患者阅读障碍的神经关联。由于阅读障碍与语音加工缺陷有关，因此我们将使用掩蔽启动来研究拼写和语音加工中涉及的自动机制。这种阅读缺陷的潜在机制可能发生在几个不同的加工阶段(例如，将拼写信息映射到音位，激活适当的音位表征)。使用掩蔽启动和大脑测量(事件相关电位(ERPs)和功能磁共振成像)将使我们能够更准确地确定这些机制中的哪一种在阅读困难中被破坏，而在熟练的读者中完好无损。先前的功能磁共振研究已经证实，在语音处理过程中，顶叶和额叶区域是重要的，而事件相关电位研究已经概述了大脑中语音处理的时间安排。在正字法加工方面，视觉词形区域(VWFA)被认为通过其在视觉词知觉中的作用来辅助语言加工，并且ERPs在正字法启动过程中建立了一系列对词形加工敏感的效应。使用功能磁共振成像和ERPs，我们将建立这些过程在大脑中何时何地发生的发育时间进程，以及它们在阅读障碍中是如何被破坏的。通过使用行为、电生理和神经成像方法，可以建立这些脑区在视觉单词知觉中的关系，以及随后这些低级别特征(词形；声音)到成功阅读所必需的高级语义上的映射。具体地说，这个项目将分三个阶段进行：第一阶段将包括fMRI和ERP实验，研究正常大学年龄人群的重复启动效应，通过单词操纵单词对之间的音位和拼写。该项目的第二阶段将再次使用fMRI和ERPs将这项研究扩展到一组发育正常的儿童(8-10岁)，该项目的最后阶段将把这一范式扩展到一组患有阅读障碍的儿童(8-10岁)。这项建议与公共卫生的相关性是能够更好地确定阅读障碍所涉及的潜在机制。这项研究将有助于建立与正常和受损阅读相关的大脑活动模式，这可能导致能够预测阅读困难或这些困难的易感性

DESCRIPTION (provided by applicant): The proposed work seeks to develop a better understanding of the developmental time course of language processing, specifically orthographic and phonological word processing during silent reading. The end goal of this project is to further elucidate neural correlates of reading deficits in dyslexia. Because dyslexia has been linked to phonological processing deficits, masked priming will be used to examine the automatic mechanisms involved in orthographic and phonological processing. The mechanism underlying this deficit in reading can be occurring at several different stages of processing (e.g., mapping of orthographic information to phonology, activating an appropriate phonological representation). Using masked priming and brain measures (event-related potentials (ERPs) and fMRI) will allow us to determine more precisely which of these mechanisms is disrupted in dyslexia and intact in skilled readers. Prior fMRI research has established that during phonological processing parietotemporal and frontal regions are important, while ERP studies have outlined the timing of phonological processing in the brain. In terms of orthographic processing, the visual word form area (VWFA) has been suggested to subserve language processing through its role in visual word perception and again ERPs have established a series of effects sensitive to word form processing during orthographic priming. Using fMRI and ERPs we will establish the developmental time course of when and where in the brain these processes occur and how they are disrupted in dyslexia. By using behavioral, electrophysiological and neuroimaging methodologies, the relationship of these brain areas in visual word perception and the subsequent mapping of these lower level features (word form; sound) onto higher level semantic meaning necessary for successful reading, can be established. Specifically, this project will take place in three stages: the first stage will consist of an fMRI and ERP experiment with a normal college-age population studying repetition priming effects with words manipulating the phonology and orthography between word pairs. The second stage of this project will extend this research to a group of normally developing children (8-10 years old) using again fMRI and ERPs and the final stage of the project will extend this paradigm to a population of children with dyslexia (8-10 years old). The relevance of this proposal to public health is being able to better determine the underlying mechanisms involved in deficits in reading. This research will be relevant for establishing patterns of brain activity associated with normal and impaired reading, which may lead to being able to predict reading difficulties or a predisposition for these difficulties