Neurocognitive Mechanisms of Positive Intervention Response in Reading Disability

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PROJECT SUMMARY / ABSTRACT Reading disabilities (RD) are the most common learning disability and are characterized by deficits in word reading accuracy and/or fluency that are not explained by general intelligence levels. Without targeted educational intervention, these deficits may persist through adolescence into adulthood. While interventions have been shown to, on average, improve reading outcomes among children with RD, gains in skill are heterogeneous. Functional MRI (fMRI) studies have revealed, unexpectedly, that children with RD who substantially improve in reading appear to do so by engaging the right inferior frontal gyrus (rIFG), despite typical reading usually involving a left-lateralized language network. Several cognitive processes tend to recruit the rIFG, ranging from verbal processes to domain-general skills such as working memory. All of these skills may support achievement in reading. However, no study has rigorously investigated what process is signified by rIFG among responders to intervention. In addition, few studies have examined how structural properties of white matter emanating from the rIFG relate to intervention responses. In this project, I will use multimodal neuroimaging to, for the first time, characterize the role of the rIFG in reading improvement among children with RD. I will recruit and characterize 90 7th-8th grade children across three groups that will be studied in subsequent aims. I will classify children with RD into two groups based on whether their age-standardized reading skills improved relative to age-expected gains (RD+) or not (RD-) following reading instruction. The third group will include typical readers (TR) matched in age, sex, and socioeconomic status. Aim 1 is to replicate findings of more rIFG activity while reading among RD+ compared to RD- and TR. For this aim, participants will undergo fMRI scanning while completing a word reading task. We will also investigate cognitive differences between RD+, RD-, and TR. Aim 2 will be to investigate what processes are signified by rIFG activation. We will collect fMRI in participants while they complete language and working memory localizers, and then find the portion of the rIFG that is most sensitive to each task in each child. We will also collect diffusion-weighted images. We will then investigate hypotheses that language, but not working memory, regions in RD+ compared to RD- and TR, are: (1) more active during reading; (2) more functionally connected to the language network during reading; and (3) more structurally connected to the language network. Findings from these aims will shed further insight into the neural bases of better or worse response to reading instruction. Our results will carry important implications for designing remediation strategies for children with RD. The novel and carefully designed methods and analyses employed in this project will serve to guide future translational neuroimaging research in RD. Through this project, I will satisfy fellowship training goals by: (1) advancing my knowledge of RD and its treatment; (2) learning about study design and execution; (3) honing my neuroimaging analysis skills; (4) gaining translational skills in working with educators and children; and (5) enhancing my professional development towards a career in science.