Fig. 21.

Surround-suppression effects on the contrast response functions for different orientations of the annular grating (indicated in key). A: the divisive normalization model (DNM) neuron with standard parameters. B: a simple cell (replotted from Cavanaugh et al. 2002b, Fig. 5A, anesthetized macaque; error bars =  ±SE). A: orientation of the center grating was 0°. Spatial frequency of the center and annulus gratings was 2.0 cpd. Size of the center grating patch was equal to the measured RF diameter (0.81°). Size of the annulus grating was 5.76°. (See phenomenon 27 in Table 1.)