Exploring the brain's reading network using multimodal neuroimaging

背景***大脑中没有单一的“阅读中心”。相反，我们的阅读能力源于多种感官、认知、语言和运动机制的动态协调。因此，它涉及到一系列连接到复杂阅读网络的大脑区域。我的实验室的长期目标是阐明这种阅读网络的认知和神经基础，特别关注跨语言和发展数据。反过来，这将使我们能够完善我们的阅读认知模型，以更好地解释不同的阅读子过程是如何在神经环境中实现的。行为和神经影像学研究表明，我们通过两个系统来阅读单词：一个是将拼写映射到声音的解码系统，另一个是获取语义的全词系统。然而，在阅读的认知理论和这些机制在大脑中的定位之间存在着显著的差距。我们提出了一项创新的研究计划，使用多种神经成像方式检查构成阅读网络的灰质和白质区域。然后将成像数据与行为测量相结合，以帮助确定这些数据如何映射到认知功能上。我们提出了一套适合网络的分析技术来表征这种阅读网络，并研究了不同语言和年龄的读者的连接结构是如何变化的。***方法***研究将使用任务和静息状态功能磁共振成像（T-fMRI和R-fMRI）、扩散张量成像（DTI）和事件相关电位（erp）来捕获阅读的神经标记。项目一的研究重点是英语的成人读者，这是一种字母语言，或普通话，它使用的是一种拼写声音一致性较弱的符号文字。fMRI和DTI被用来表征不同阅读网络通路内的连接模式，然后将其与阅读能力和策略的行为测量相关联。在项目2中，我们研究了全词和语音解码阅读通路的参与在阅读习得过程中是如何变化的。我们提出了适合年龄的ERP和fMRI方法来分离阅读子过程，并追踪阅读发展过程中的网络变化。***意义***这项工作将提供一个更清晰的画面，在阅读过程中多个大脑区域是如何协调的，以及发展和经验是如何塑造这个网络的。研究结果不仅有助于理解大脑和行为之间的联系，还有助于制定更好的阅读指导政策，以及识别和纠正阅读障碍

Background***There is no single ‘reading centre' in the brain. Instead, our ability to read arises from the dynamic orchestration of multiple sensory, cognitive, linguistic and motor mechanisms. It therefore involves a range of brain regions connected into a complex reading network. A long-term goal of my laboratory is to elucidate the cognitive and neural underpinnings of this reading network, with a special focus on cross-linguistic and developmental data. This in turn will allow us to refine our cognitive models of reading to better account for how different reading sub-processes are implemented in a neural context. ***Purpose***Behavioural and neuroimaging research suggests we read words via two systems: a decoding system that maps spelling to sound, and a whole-word system that accesses semantics. However there is a significant gap between cognitive theories of reading and the localization of these mechanisms in the brain. We propose an innovative research program that examines grey- and white matter regions that comprise the reading network, using multiple neuroimaging modalities. Imaging data are then merged with behavioural measures to help identify how these map onto cognitive function. We propose a set of network-appropriate analytic techniques for characterizing this reading network, and examine how its connectivity structure varies among readers of different languages and ages.***Methods***Studies will use task- and resting-state functional magnetic resonance imaging (T-fMRI and R-fMRI), diffusion tensor imaging (DTI), and event-related potentials (ERPs) to capture neural markers of reading. Studies in Project 1 focus on adult readers of English, an alphabetic language, or Mandarin Chinese, which employs a logographic script with weak spelling-sound consistency. fMRI and DTI are used to characterize connectivity patterns within different reading network pathways, which are then correlated with behavioural measures of reading ability and strategy. In Project 2, we examine how the involvement of whole-word and phonological decoding reading pathways changes over the course of reading acquisition. We propose age-appropriate ERP and fMRI methodologies to isolate reading sub-processes, and trace network changes over the course of reading development.***Significance***This work will provide a clearer picture of how multiple brain regions are coordinated during reading, and also how development and experience shape this network. The results have implications not only for understanding how brain and behaviour are linked, but also for developing better reading instruction policies and for the identification and remediation of reading disorders.**