Abnormal Developmental Trajectories in the Brain in Individuals With Reading Disability

It is unknown how the brain supports reading development in individuals with reading disability (RD). In a cross-sectional study (i.e., children, adolescents, adults), we found an age-related shift in brain activation from posterior to anterior part of the left occipitotemporal (OT) area in typical readers, supporting orthographic specialization, while RD readers did not show such a developmental shift. Furthermore, RD readers did not show age-related increase in the left superior temporal gyrus as did the typical readers, suggesting persistent phonological deficits. On the other hand, RD readers but not typical readers showed age-related increase in the left inferior frontal gyrus and the supplementary motor area. These findings suggest that the experience of RD derails the developmental trajectory of the brain. Insights gained from our study not only advance our understanding of the prognosis of RD, but also facilitate the development of age-appropriate treatment for RD. SUMMARY: Individuals with reading disability (RD) consistently underperformed at both phonological awareness and orthographic awareness, irrespective of their age. RD was characterized by a persistent functional deficit in the left occipitotemporal (OT) regions across different age groups. A gradual shift of functional deficits within the left OT regions, transitioning from posterior/medial to anterior/lateral areas, was associated with RD as they aged. The neural transition is closely linked to orthographic specification in OT regions.