The White Matter Connectome Supporting Speech and Language in the Human.

The neurobiology of language has moved beyond the classical dorsal-ventral dichotomy to embrace a more complex, distributed, and dynamic white matter connectome. This special issue, The White Matter Connectome Supporting Speech and Language in the Human, presents 10 empirical studies that leverage traditional and advanced diffusion modeling and analyses-including Restriction Spectrum Imaging, fixel-based analysis, and network control theory-to map this complexity. The contributions are organized into three themes: developmental plasticity, lateralization, and clinical resilience. Findings range from the rapid consolidation of speech categories during sleep and the microstructural scaffolding of early childhood speech, to the surprising stability of reading networks following educational disruption. Novel insights into lateralization challenge binary left-right models, revealing how interhemispheric balance and intrahemispheric asymmetry jointly shape functional dominance. Finally, clinical studies on aphasia, dyslexia, and stroke recovery demonstrate how structural connectivity constrains therapeutic outcomes, identifying specific white matter targets for semantic versus phonological recovery. Collectively, these articles advance a framework where the white matter connectome is not merely a static system, but an active, plastic substrate essential for human communication.