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，我们的阅读能力来自于多种感官、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一个复杂的阅读网络的大脑区域。我的实验室的一个长期目标是阐明这个阅读网络的认知和神经基础，特别关注跨语言和发展数据。这反过来将使我们能够完善阅读的认知模型，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。 目的 行为和神经成像研究表明，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，另一个是访问语义的全词系统。然而，阅读的认知理论与这些机制在大脑中的定位之间存在着巨大的差距。我们提出了一个创新的研究计划，检查灰色和白色物质区域，包括阅读网络，使用多种神经影像学方式。然后将成像数据与行为测量合并，以帮助确定这些如何映射到认知功能。我们提出了一套网络适当的分析技术来表征这个阅读网络，并研究其连接结构如何在不同语言和年龄的读者之间变化。 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1的研究集中在英语（一种字母语言）或汉语普通话的成年读者，汉语普通话采用拼写声音一致性较弱的语标文字。功能磁共振成像和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，我们研究了整个词和语音解码阅读途径的参与在阅读习得过程中的变化。我们提出了与年龄相适应的ERP和fMRI方法来分离阅读子过程，并跟踪阅读发展过程中的网络变化。 意义 这项工作将更清晰地了解多个大脑区域在阅读过程中如何协调，以及发展和经验如何塑造这个网络。这些结果不仅对理解大脑和行为之间的联系有意义，而且对制定更好的阅读指导政策以及识别和补救阅读障碍也有意义。

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.