Unravelling the Hidden Wiring of Human Vision

Visual perception relies on ocular dominance columns—specialised stripes of neurons in the visual cortex that prefer input from one eye over the other. While their structure is well-documented, understanding how these columns communicate within the living human brain has remained a significant challenge. A new study has now shed light on this ‘mesoscale’ connectivity.

By employing high-resolution functional MRI on 12 adults, researchers assessed ‘resting-state functional connectivity’—essentially tracking how synchronised brain activity is between different regions when the mind is at rest. The results aligned with anatomical studies in animals, showing that connectivity is most robust in the middle depths of the cortex. Crucially, the team found that columns sharing the same ‘ocular polarity’ (preference for the same eye) maintained significantly stronger links with one another than with those favouring the opposite eye.

Going beyond previous animal models, the study uncovered patterns consistent with human perceptual biases. Connectivity was found to be stronger in the peripheral subregions of the visual field compared to the central, and in the dorsal (upper) areas compared to the ventral (lower). These findings highlight a significant heterogeneity in how our primary visual cortex is wired, suggesting that these connectivity patterns are closely linked to the specific features of how we perceive the world.