On the relationship between interocular suppression in the primary visual cortex and binocular rivalry, Brain and Mind 2: 39–54

Abstract. Both classical psychophysical work and recent functional imaging studies have suggested a critical role for the primary visual cortex (V1) in resolving the perceptual ambiguities experienced during binocular rivalry. Here we examine, by means of single-cell recordings and optical imaging of intrinsic signals, the spatial characteristics of suppression elicited by rival stimuli in cat V1. We find that the “interocular suppression field ” of V1 neurons is centred on the same position in space and is slightly larger (by a factor of 1.3) than the minimum response field, measured through the same eye. Suppression is always strongest at a single position corresponding very closely to the centre of the classical receptive field, and reduces responses through the other eye by up to 90 % but typically around 40%. The spatial pattern of interocular suppression, as revealed by optical imaging, closely matches the cortical representation of the stimulus, which is being suppressed, both in terms of its orientation and the eye of origin. These results indicate that interocular suppression is directly related to the functional architecture of V1; it is probably caused by direct inhibitory interactions between neighbouring cortical columns of opposite ocular dominance