Representational similarity of hemodynamic brain responses to written and spoken words increases when learning to read

Learning to read requires linking auditory and visual information, yet how the developing brain maps information across sensory modalities remains poorly understood. To shed light on this topic we employed functional MRI to investigate hemodynamic brain responses during spoken and written word or pseudoword recognition in 61 primary school children with different levels of reading experience. Audiovisual representational similarity of activation patterns in the inferior frontal gyrus, inferior parietal lobule, superior temporal gyrus, and temporo-occipital cortex, increased linearly with school grade and this effect was largest in the left posterior superior temporal gyrus. Our results suggest that learning to read is related to a progressively increasing similarity of auditory and visual word representations within canonical language areas.