Exploring the brain's reading network using multimodal neuroimaging

点击翻译按钮获取中文摘要

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.**