Fig. 3.

Extraclassical inhibition in marmoset LGN.A–C, Responses of one PC (A), one MC (B), and one KC (C) cell to optimal spatial frequency gratings as a function of aperture radius.Solid lines show predictions of the model described in Figure 2C. Arrows show the radii of center (open arrows) and surround (filled arrows) components of the DOG model, as described in Figure2A. The KC cell had coextensive center and surround. All cells show a reduction in response in large apertures. The magnitude of this reduction (amplitude in 6° radius aperture as a percentage of maximum amplitude) was: PC cell, 67.1%; MC cell, 53.2%; and KC cell, 70.4%. Error bars are ± 1 SEM for at least 40 stimulus cycles. D–F, Response suppression for each subdivision of the LGN. Solid bars in Fshow “blue-on” cells. Stimulus and fit parameters:A, 2.4 cycles/°, 50% contrast,r_c = 0.076,r_s = 0.333,r_e = 0.185,r_i = 1.08; B, 0.8 cycles/°, 25% contrast, r_c = 0.135,r_s = 0.647,r_e = 0.481,r_i = 1.279; C, 0.4 cycles/°, 80% contrast, r_c = 0.145,r_s = 0.145,r_e = 0.922, r_i = 0.939.