Fig 5. The most suppressive surround can follow the center color change.

A. Averaged color correlation of the center the surround in VGG16 (left) and Alexnet (right). Higher values indicate higher color similarity between the center and surround. Four conditions are shown in the plot: the correlation between the optimal center and the most suppressive surround (solid blue); the optimal center and the most facilitative surround (solid red); the altered center and the most suppressive surround (dotted blue); the altered center and the most facilitative surround. The optimal center is defined as the most facilitative center. The altered center is the optimal center with three color channels permuted. The shaded area indicates the standard deviation. B. Two example neurons (VGG_L7_N7 and (VGG_L10_N55)) showing that the most suppressive surround can match the center color. For each neuron, the first row are the center stimuli; the second row are the center stimuli with the most suppressive surround; the third row are the center stimuli with the most facilitative surround. The first column is the optimal center; other columns are the optimal center with the three color channels permuted. The area of the red bars on the right of each image represents the normalized response (relative to the optimal center response).