Neurocognitive Basis of Language Comprehension in Children with Dyslexia

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Developmental dyslexia (dyslexia) is an unexplained difficulty in learning to read, affecting approximately 10- 12% of all children. Dyslexia is characterized by deficits that result in slower and less accurate decoding, important prerequisites for adequate reading comprehension, the overall goal of reading. As children progress in school, when instructional focus shifts from “learning to read” to “reading to learn,” reading comprehension becomes increasingly critical to academic success. Although much is known about the neurocognitive basis of impaired single-word decoding in dyslexia, very little is known about the neurocognitive basis of impaired reading comprehension in dyslexia. This is a major gap in knowledge, as it is the comprehension impairment that places the greatest burden on children with dyslexia throughout their education. Guided by the conceptual framework of the Simple View of Reading, the current proposal will address this gap by investigating the neural and cognitive components of reading comprehension in children with dyslexia (Dys) and their typically developing peers (Typ). I will recruit 30 Typ and 30 Dys second and third grade children, matched in age, gender, and parental education levels. All children will be comprehensively assessed using tests of oral language, reading, and cognitive skills. Structural and functional magnetic resonance imaging data will also be collected. I will examine the structural substrates of listening comprehension and decoding, and observe how they vary between Typ and Dys. I will relate functional brain activation during listening comprehension and decoding tasks to children’s out-of-scanner reading comprehension performance separately in Dys and Typ. Finally, I will test whether cognitive and linguistic factors, as well as brain structure, mediate the association between decoding and reading comprehension differently across the two groups. Knowledge gained from this project will provide a better understanding of variation in reading comprehension skills in dyslexia, and potentially inform assessment and remediation efforts for children with dyslexia and poor comprehension. The proposed study will provide ample opportunities to complete the fellowship training goals by advancing the following: 1) conceptual understanding of language development and comprehension, 2) technical expertise in advanced behavioral and neuroimaging methods, and 3) translational knowledge of how children with developmental language disorders are helped in clinical settings.