Brain Mechanisms underlying skilled reading in deaf and hard of hearing (DHH) children with different communication modes

项目摘要 许多失聪和听力困难的儿童（DHH）的斗争与阅读和严重的损害，一些 孩子随年龄增长而增加。尽管如此，我们对成功阅读的大脑机制知之甚少。 DHH儿童，或是否依赖于某些机制不同的沟通模式。我们不知道为什么 一些DHH的孩子是好的阅读者，而另一些则不是。我们利用了巨大的个体差异， 阅读技能，以确定如何更好地阅读依赖于不同的机制，以及这是否随 通信模式。该项目使用功能磁共振成像（fMRI）在10至15岁的听力 儿童以及DHH儿童中主要的手语，主要的口头语言，或双峰 语言创新的纵向方法跟踪儿童两年后，并允许调查如何 阅读能力的提高与大脑随时间的变化有关，也与大脑随年龄的变化有关。总体理论 阅读习得是一个三角形模型，它有三个表征系统，包括正字法（拼写）， 语音（声音）和语义（意义），以及这些系统之间的映射路径。一 这个项目的基本优势是扩展了成熟的三角模型，以制定第一个 DHH儿童阅读的神经认知模型我们的项目测试了三角模型的关键假设，包括 正字法表征、正字法到语音映射以及正字法到语义映射的本质 映射.我们测试了这些成分是如何与DHH儿童随时间的技能和发展变化相关的 不同的通信模式。该项目的另一个创新方面是使用“定位器”功能磁共振成像任务， 独立识别与语音机制相关的颞顶叶皮层区域 阅读、手语和口语语音，以及与中间语义机制相关的区域 颞回独立定位器任务的使用为我们理解 DHH儿童熟练阅读的潜在神经机制孩子们还完成了两个阅读功能磁共振成像 任务，一个涉及押韵的判断和其他涉及的意义判断的话视觉。不 我们只研究了语音和语义机制与阅读的关系，但我们的新方法也 检查这些区域与梭状皮质的连接，这些梭状皮质参与正字法处理。除了有 功能磁共振成像测量，所有儿童完成了广泛的电池的国家最先进的行为测试测量签署 语言、口语和阅读。该项目的重点是对单词解码的个体差异，因为这是 是阅读的重要组成部分，但我们也研究了阅读理解中的行为差异。

PROJECT SUMMARY Many deaf and hard-of-hearing (DHH) children struggle with reading and the severity of the impairment for some children increases with age. Despite this, we know very little about the brain mechanisms for successful reading in DHH children, or whether reliance on certain mechanisms differs with communication mode. We do not know why some DHH children are good readers and other are not. We take advantage of the large individual differences in reading skill to determine how better reading relies on different mechanisms and whether this varies with communication modes. This project uses functional magnetic resonance imaging (fMRI) in 10- to 15-year-old hearing children as well as in DHH children with predominant signed language, predominant oral language, or bimodal language. The innovative longitudinal approach follows children two years later and allows an investigation of how reading gains are related to brain changes over time and whether this varies with age. The overarching theory of reading acquisition is the Triangle Model which has three representational systems, including orthography (spelling), phonology (sound) and semantics (meaning), as well as pathways for mapping between these systems. A fundamental strength of this project is extending the well-developed Triangle Model to formulate the first neurocognitive model of reading in DHH children. Our project tests critical assumptions of the Triangle Model including the nature of orthographic representations, of orthographic to phonological mapping and of orthographic to semantic mapping. We test how these components are related to skill and developmental change over time in DHH children with different communication modes. Another innovative aspect of the project is the use of `localizer' fMRI tasks to independently identify regions associated with phonological mechanisms in temporo-parietal cortex during speech reading, signed language and spoken phonology, as well as regions associated with semantic mechanisms in middle temporal gyrus. The use of independent localizer tasks provides fundamental advances in our understanding of the underlying neural mechanisms involved in skilled reading in DHH children. Children also complete two reading fMRI tasks, one involving rhyming judgments and the other involving meaning judgments to words presented visually. Not only do we examine how phonological and semantic mechanisms are related to reading, but our novel approach also examines connectivity of these regions with fusiform cortex involved in orthographic processing. In addition to the fMRI measures, all children complete an extensive battery of state-of-the-art behavioral tests measuring signed language, oral language and reading. The focus of the project is on individual differences on word decoding as this is a critical building block to reading, but we also examine behavioral differences in reading comprehension.