Binocular receptive-field construction in the primary visual cortex.

ON and OFF thalamic afferents from the two eyes converge in the primary visual cortex to form binocular receptive fields. The receptive fields need to be diverse to sample our visual world but also similar across eyes to achieve binocular fusion. It is currently unknown how the cortex balances these competing needs between receptive-field diversity and similarity. Our results demonstrate that receptive fields in the cat visual cortex are binocularly matched with exquisite precision for retinotopy, orientation/direction preference, orientation/direction selectivity, response latency, and ON-OFF polarity/structure. Specifically, the average binocular mismatches in retinotopy and ON-OFF structure are tightly restricted to 1/20 and 1/5 of the average receptive-field size but are still large enough to generate all types of binocular disparity tuning. Based on these results, we conclude that cortical receptive fields are binocularly matched with the high precision needed to facilitate binocular fusion while allowing restricted mismatches to process visual depth. [Display omitted] • Cat area V1 limits binocular position disparity to 1/20 of a receptive field • Binocular mismatches are 4 times larger for receptive-field structure than position • Receptive-field count decreases exponentially with the mismatch magnitude • V1 receptive-field availability prioritizes binocular fusion over binocular depth Olianezhad et al. demonstrate that carnivores have binocular V1 receptive fields exquisitely matched in position but show much larger mismatches in structure. Receptive-field availability decreases exponentially with the magnitude of the binocular mismatch, making cortical processing more efficient at computing binocular fusion than visual depth. [ABSTRACT FROM AUTHOR]