Magnocellular-biased interocular integration during onset rivalry in normal vision and binocular imbalance

Previous studies have indicated that the magnocellular (M) pathway may resist binocular rivalry, but the roles of the M and parvocellular (P) pathways in binocular rivalry and integration have been unclear, as was whether these pathways show different deficits in visual disorders. This study used a self-designed dichoptic paradigm to investigate the roles of the M and P pathways in interocular integration and onset rivalry in normal and unbalanced vision. Results showed that interocular motion integration increased with higher temporal and lower spatial frequencies, aligning with M pathway properties. The normal group had significantly higher integration compared to amblyopia, acute acquired comitant esotropia (AACE), and intermittent exotropia (IXT) groups, with amblyopia patients showing the lowest integration. These findings suggest that M pathway-biased information persists during onset rivalry in both normal and impaired vision, with amblyopia showing more severe impairment but still integrating some M pathway-biased information. Despite realigned eyes, strabismus patients exhibit abnormal binocular interaction.