/Aba/ or /ada/, that is the question: Longitudinal investigation of letter-speech sound processing in children with and without developmental dyslexia

Learning to read is a major achievement in a child’s development. Yet, children reach very different reading levels, with 5-10 % of children facing persistent problems due to developmental dyslexia. This PhD project aimed to understand neuro-behavioral learning processes underlying these individual differences. It focused on a fundamental step in reading development, the association between letters and speech sounds, and investigated how 8 – 11 year-old children with and without dyslexia learn to make these associations using a magnetic resonance imaging scanner and a task specifically designed for children. The children performed this task once a year over a three-year period. These results show that how well a child learns to read relates to their audio-visual brain responses to text and speech sounds and that children with dyslexia show less activation in a brain area specialized for text processing. Changes in brain activation over the three year period reflected a switch from slow and effortful to fast and automatic reading.