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Fig. 5.19. Effect of disparity on ocular dominance maps. Each row presents a different simulation using the same network but a different degree of disparity between the inputs in the two eyes. From left to right, each row shows a retinal activation (left and right eyes), final RFs of a set of sample neurons, their lateral connections, the OD preference map, its histogram, and the OD selectivity map. For comparison, the results from brightness differences are reproduced in the top row (labeled "Dimming"), and the results from strabismic maps in the bottom row. The main result is that OD maps can be obtained from disparity differences (with no brightness differences), but the results do not match animal maps well. Small amounts of disparity (scatter s_s = 0.2) result in unrealistically clear boundaries between stripes even with relatively weak OD preferences (row "Mild"), as is evident in the histogram. Moderate disparity (s_s = 0.4; row "Moderate") approaches the strabismic results, with strongly monocular RFs, sharp stripe boundaries, and connections only to neurons that prefer the same eye, unlike in normal animals. These results suggest that ocular dominance patterns can result from differences in either position or brightness, but brightness differences lead to maps that more closely match those found in animals.