Figure 3: A 2-layer hierarchical model of disparity tuning and selection. When an image is shown to the two eyes, depending on its disparity, its projection in one of the eyes is shifted. The receptive field of the disparity tuned cell is composed of subfields from the two eyes projected on the lower cortical layer. Therefore, for different disparities and different shifted subfields, different disparity tuned cells respond. Both the layers of the cortex are topographically arranged.