Vanvooren, S. 1, 2 , De Vos, A. 1, 2 , Ghesquière, P. 2 & Wouters, J. 1
1 KU Leuven, Department of Neurosciences, ExpORL, Leuven, Belgium
2 KU Leuven, Parenting and Special Education Research Unit, Leuven, Belgium
Several theories suggest that the literacy impairments observed in individuals with dyslexia are a symptom of atypical lower level auditory processing. A variety of auditory processing differences have been proposed in poor readers, at the level of the brainstem, cortex or both. The precise nature of neural auditory impairments in individuals with dyslexia, as well as the occurrence before or during early reading development, remains unclear. In the current study, cortical and brainstem auditory evoked potentials to 4, 20 and 80 Hz rate modulations were measured in 87 children at high and low family risk for dyslexia during the development from prereader (5 years) to beginning reader (7 years). Our results show maturational differences, indicating that the start of reading acquisition exerts a top-down influence on the emergence of mature hemispheric specialization. Only a small effect of family risk for dyslexia could be observed at cortical level, suggesting no major effect of hereditary risk on the processing of cortical auditory cues in beginning readers. However, an influence of dyslexia phenotype was shown at brainstem level, demonstrating that subcortical auditory processing mechanisms may play a role in the development of reading disorders during the first year of reading instruction.