Long-range white-matter pathways enable efficient spontaneous neural activity propagation in the human brain

Efficient communication across long anatomical distances is fundamental for the human brain. By integrating stereo-EEG with diffusion spectrum imaging, this study shows that brain-wide information propagation is not determined by distance alone, but is critically supported by long-range white-matter pathways, their microstructural properties, and intrinsic functional network organization. We also find that both pathological epileptiform discharges and physiological spontaneous activity follow shared propagation rules, exhibiting distance saturation, structural facilitation, and preferential within-network transmission. These findings provide a microstructure-grounded account of how the human brain achieves fast, efficient large-scale communication, bridging macroscale connectome architecture with millisecond-scale neural dynamics.