The structural covariance of reading-related brain regions in adults and children with typical or poor reading skills

Structural covariance (SC) is a promising approach for studying brain organization in the context of literacy and developmental disorders, offering insights into both structural and functional underpinnings and potential experience-dependent co-development of functional brain networks. Here, we explore the influence of maturation and reading skill on SC in reading-related brain regions. Whole-brain SC analyses were conducted for six key regions of the reading network, including an anterior and posterior subdivision of the visual word form area (VWFA). To study maturational effects, SC was compared between typical-reading adults (N = 134, 25.3 ± 4 yrs) and children (N = 110, 9.6 ± 1.6 yrs). The impact of reading skills on SC was assessed by comparing typical-reading children (N = 110, 9.6 ± 1.6 yrs) to children with poor reading skills (N = 68, 10.2 ± 1.4 yrs). Our results showed significant SC between reading-related brain regions in typical-reading adults. Further, we observed significant SC between the posterior VWFA and the occipital cortex, and between the anterior VWFA and the superior temporal and inferior frontal gyri. There was no indication of a major change in SC within the reading network related to maturation. However, we observed higher SC between the inferior parietal lobule and other reading-related brain regions in children with typical compared to poor reading skills.