Fig. 4
Stimulus size does not explain blur selectivity. a A blurred stimulus (β = 0.16) has an increased foreground area, defined as the number of pixels distinct from the background, compared to its original boundary prior to blurring (red). Stimuli scaled by  ± 10% are shown for comparison (blue), and correspond to luminance thresholds approximately 1/3 and 2/3 of maximum, respectively. b Example scaled and blurred stimuli used to assess a potential size confound. c, d Results of the size control experiment for cells a15 and b27 demonstrate increased responses for intermediate blur irrespective of stimulus size. Line color represents stimulus identity per Fig. 2d, f. For both neurons, responses were not significantly influenced by size (p = 0.45 and p = 0.18, respectively) but significant variance was found with respect to blur (p < 0.0001). Error bars indicate s.e.m.
