Hierarchical Network Adaptations and Structure-Function Scaffolding in the Deaf Adult Brain

Cortical networks reorganize following early sensory deprivation, yet the relationship between structural architecture and large-scale functional organization remains incompletely understood. We examined connectome organization in 54 congenitally deaf adults and matched hearing controls using resting-state functional MRI, diffusion tensor imaging, and graph-theoretical analysis. Deaf individuals exhibited higher global efficiency and lower local efficiency, indicating a shift toward distributed integration with reduced regional segregation. These effects were most prominent in auditory, multisensory, and associative cortices. Diffusion measures showed reduced fractional anisotropy in auditory pathways, with relatively preserved white-matter organization in visual and parietal regions. At the regional level, functional topology showed coordinated correspondence with local white-matter organization, whereas network-averaged structure-function associations were not significant. Multivariate analyses further indicated structured alignment between structural and functional measures within altered territories. Overall, congenital deafness is associated with large-scale reconfiguration of cortical network topology, accompanied by spatially selective variation in white-matter architecture. These findings suggest that early sensory experience shapes intrinsic connectome organization through coordinated, regionally specific adaptations rather than uniform network change.