What do we know about the Vertical Occipital Fasciculus? A systematic review.

The Vertical Occipital Fasciculus (VOF) is a vertically oriented white matter tract that connects dorsal and ventral visual cortices and plays a key role in visual integration. First described by Wernicke in 1881 in monkeys, the VOF remained largely overlooked for nearly a century before its re-emergence in modern neuroanatomical literature with the advent of diffusion MRI and advanced tractography techniques. Since then, a growing body of research has examined its anatomical characteristics, methodological challenges in its delineation, functional significance, and evolutionary conservation across species. This systematic review synthesizes diffusion imaging studies, white matter microdissection findings, and functional neuroimaging evidence. Collectively, the evidence supports the VOF as a distinct association pathway linking dorsal and ventral visual streams, contributing to the integration of spatial, attentional, and object-related visual information. The review further highlights the involvement of the VOF in higher-order visual functions, particularly reading, visually guided action, and visuospatial cognition, as well as its alteration in a range of neurological and neuropsychiatric conditions. Persistent controversies regarding its precise boundaries and terminations are discussed in light of methodological variability and recent advances. Overall, the VOF emerges as a critical component of the human visual connectome whose study provides important insights into visual processing, network-level brain organization, and disease-related disconnection.