Figure 4.

Disparity processing in the ventral visual pathway of macaques. The information represented by disparity-sensitive neurons in the ventral pathway becomes progressively more complex. Disparity processing originates in V1 where neurons signal absolute disparity. As early as V2, some neurons encode the relative disparity between a centre stimulus and a surrounding annulus (see pictogram below). Apart from relative disparities, neurons in V4 can be tuned to the orientation in depth of a planar stimulus. Neurons in STSv provide information about relative disparity (position in depth) or surface orientation, but also about which smoothly curved 3D shape is presented. Several regions in the ventral pathway may interact (dashed arrows) with regions outside the ventral pathway, such as MT, AIP or VLPFC, to facilitate depth perception. AIP, anterior intraparietal area; VLPFC, ventro-lateral prefrontal cortex.