How does the brain learn to read? It is clear that the brain must undergo profound changes as child learns to read ? one of the most fundamental observations about the literate brain is that there is a region in visual cortex that is specialized for processing text ? but few longitudinal studies have focused on the emergence of this circuitry over the early days of reading instruction. This proposal seeks to understand how a young child?s first experiences with reading, tune circuits in visual cortex to selectively respond to text, and induce changes in the underlying structure of the brain?s visual and language pathways. Forty pre-reading children will be recruited during the summer before kindergarten and will be randomly assigned to a program involving either (a) systematic training in letter recognition, letter-sound correspondence and phonological awareness or (b) listening to stories without any exposure to text. Magnetoencephalography (MEG) measures of cortical responses and quantitative magnetic resonance imaging (qMRI) measures of white matter tissue properties will be collected one week before, one week after and one year after the training program. This study will answer three fundamental questions about the neural mechanisms that underlie reading development, setting the stage for investigating individual differences in how children learn to read. First, we will determine whether the process of learning to recognize letters is sufficient to prompt the development of text-selective brain circuits or if this change requires more substantial experience with reading over the course of kindergarten. Second, we will measure how the process of learning to read affects the visual response to other categories of images to test the theory that reading ?invades? cortical circuits that evolved for face and object recognition. Finally, we will examine whether these early educational experiences induce structural changes in the developing brain. A deeper understanding of the mechanisms of typical reading development will pave the way for studies targeting these mechanisms in children with, or at risk for, dyslexia.
Dyslexia, an impairment in accurate or fluent word recognition, is the most common learning disability affecting roughly ten percent of children. This proposal capitalizes on cutting edge neuroimaging methods, in combination with carefully controlled educational interventions and behavioral measurements, to generate a new understanding of how a child?s experience with reading instruction, shapes the development of specialized brain circuits that support this critical cognitive function. A deeper understanding of the mechanisms of typical reading development will pave the way for studies targeting these mechanisms in children with, or at risk for, dyslexia.
