Figure 9.

Spatial frequency tuning of CRF and suppressive mechanisms in an MC cell. Responses to a matrix of size and spatial-frequency are shown for drifting gratings of low contrast (A, B) or high contrast (C, D). Two slices through the matrix are shown: size-tuning is plotted for three of the eight spatial frequencies (A, C), or spatial frequency tuning is shown for three of the eight patch diameters (B, D). At low contrast, the effect of patch size is strongest at low spatial frequencies. At high contrast, the neuron is tuned for patch size at all spatial frequencies. The smooth lines in B and D are fits of a difference-of-Gaussians function to the responses in large patches.