Shared anomalies in cortical reading networks in Chinese and French dyslexic children

To determine whether the neural anomalies underlying developmental dyslexia are universal across languages or influenced by the writing system, we tested 10-year-old Chinese and French children, with or without dyslexia, in a cross-cultural fMRI paradigm. We compared their brain responses to words written in their known script, faces and houses while they were asked to detect a rarely presented star. We observed that impaired reading scores were correlated with a decreased activation to words in several key regions of the reading circuit, including left fusiform gyrus, superior temporal gyrus/sulcus, precentral and middle frontal gyrus. In ROIs previously reported as sensitive to dyslexia, we observed main effects of dyslexia common to Chinese and French readers, without interaction with the children9s native language, suggesting a cross-cultural invariance in the neural anomalies underlying dyslexia. Multivariate pattern analyses further confirmed that dyslexics exhibit a reduced activation to written words in the left fusiform gyrus and left posterior superior temporal gyrus, and not merely a greater inter-individual variability. The impairments in these regions may reflect the causes as well as the consequences of orthographic and phonological deficits in dyslexia in different languages. The current study highlights the existence of common brain mechanisms for dyslexia even in highly different writing systems.