NEUROBIOLOGY OF READING COMPENSATION

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PROJECT SUMMARY / ABSTRACT Literacy is associated with educational, socioeconomic, and health outcomes. A critical public health issue, low literacy has been linked to over 230 billion dollars a year in health care costs. Developing proficient literacy is dependent upon the ability to develop adequate reading skills, allowing for the transition from word reading to reading for comprehension. The majority of theoretical models of reading have focused on only specific reading skills, such as single-word reading. In contrast, the “Reading System Framework” provides the scaffolding to investigate the link from word reading to reading comprehension, by way of lexical-semantic knowledge. The long-term objectives of this proposal are to parse the mechanisms of typical and compensatory brain activation for word reading to determine how these differences correspond to behavioral heterogeneity in children’s reading comprehension. Decades of neuroimaging research have provided consistent evidence that skilled readers rely on a complex, highly organized neurological system built during the process of learning to read. However, compensatory brain activation during this learning process is not yet well established. Controversy surrounds the question of whether reliance on compensatory brain regions at the single-word level facilitates or hinders reading comprehension. Annually collected, longitudinal extant data from a functional Magnetic Resonance Imaging (fMRI) word reading task, is complemented by standardized cognitive and reading assessments. The fMRI task was chosen because it has been shown to reflect characteristics of individual’s reading network rather than task stimulus demands. This is particularly important in the case of our longitudinal dataset, which contains children spanning the reading ability continuum from good-to-poor readers. The current study aims to determine and predict the intra-individual impact of neurobiological compensatory mechanisms on reading development. In Aim 1, during the process of word reading, we examine the development of the left-hemisphere Visual Word Form Area (VWFA) and its right-hemisphere compensatory homologue. In Aim 2, we investigate how the continued use of compensatory brain regions impacts reading comprehension. Improved knowledge of typical and compensatory brain development has the potential to reveal key biomarkers for increasing literacy.