Comparison of brightness and contrast induction

Abstract

Lateral spatial interactions in the visual nervous system are commonly adduced to account for a variety of simultaneous contrast (induction) phenomena with regard to the perception of both brightness1 and spatial contrast.2 The relationship of these two systems of lateral interaction has not been clarified. Available evidence suggests that the lateral interactions governing perceived contrast embody a form of multiplicative contrast gain control.2 Evidence is presented that the lateral interactions governing brightness perception are similarly the result of multiplicative luminance-gain control, in addition to a subtractive (zero-offset) process. Utilizing the grating induction paradigm1 in association with a contrast-matching procedure, the inducing grating spatial frequency was varied across a range of eight octaves (0.0625-16.0 c/d), encompassing a clear transition in the form of lateral interactions from ones based on a luminance-gain control mechanism to those based on a contrast-gain control mechanism.