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Divergent developmental profiles of cortical morphometric similarity networks in Chinese developmental dyslexia
Poster Session E, Friday, October 2, 11:00 am - 1:00 pm, Wangari Maathai
Xiao Li1, Ting Qi1, Fan Cao2; 1Beijing University of Posts and Telecommunications, 2The University of Hong Kong
Developmental dyslexia (DD) is associated with atypical neural organization for reading, but it remains unclear whether DD-related structural network alterations are stable across development or follow heterogeneous developmental trajectories. Here, we used morphometric similarity networks to examine cortical network organization in Chinese children and adults with and without DD. We analyzed T1-weighted MRI and behavioral data from 204 Chinese readers, including 92 DD and 112 typically developing controls. The sample includes 117 children and adolescents (66 DD, 51 controls) aged between 9 and 14.5 and 87 adults (26 DD, 61 controls) aged between 18 and 22. Morphometric similarity networks were constructed across 318 cortical nodes of the Desikan atlas using the Morphometric INverse Divergence (MIND) framework, and nodal strength was computed for each node. Double generalized linear models (DGLM) were applied to examine both mean and variance effects of Diagnosis, AgeGroup, and their interaction, controlling for sex. We then computed TD–DD t-statistic maps separately for children/adolescents and adults and applied K-means clustering across cortical nodes to identify heterogeneous developmental profiles. DGLM revealed significant main effects of Diagnosis and AgeGroup, but no significant interaction. Compared with controls, DD showed reduced nodal strength in a distributed temporo-frontal network extending to posterior parietal and medial posterior regions, consistent with structural network alterations previously implicated in dyslexia. Age Group effects were more widespread, consistent with broad maturational differences in cortical network organization. The absence of a global interaction motivated a follow-up clustering analysis to characterize spatially heterogeneous age-specific DD profiles. Clustering of age-specific TD–DD effect maps identified five DD-related profiles. C1 showed stable, age-invariant reductions across a posterior multimodal network. C2 and C4 showed DD-related reductions in both age groups, but the TD–DD difference was larger in adults for C2, involving reading-related temporal–perisylvian regions, and larger in children for C4, involving a right-lateralized association network. C3 and C5 showed more age-specific patterns, with C3 more evident in adults and C5 more evident in children. Notably, only C5 showed significant Diagnosis × Age Group effects, localized to the left precuneus and right V1. One cluster showed stable, age-invariant deficits across widespread frontal, parietal, temporal, and occipital regions (C1). Behavioral analyses further linked these network profiles to reading-related skills. C1, C2, and C4 showed association with reading-related measures within the DD group, suggesting that these profiles were not only altered in DD but also related to individual differences among individuals with DD. Specifically, C1 nodal strength was correlated with homophonic morpheme awareness; C2 nodal strength was correlated with character correction, homophonic morpheme awareness, and word fluency; and C4 nodal strength was correlated with character correction, homographic morpheme awareness, and homophonic morpheme awareness. In contrast, C3 and C5, showed behavioral associations mainly at the full sample or within age-specific full samples, suggesting broader reading-related variation rather than DD-specific variability. Together, these findings suggest that DD-related structural network alterations are heterogeneous rather than reflecting a single static abnormality. These profiles capture both persistent alterations linked to reading-related variability within DD and age-sensitive changes in cortical structural organization.
Topic Areas: Disorders: Developmental,