Much of our information about spatial vision comes from detection experiments involving low-contrast stimuli. Contrast discrimination experiments provide one way to explore the visual system's response to stimuli of higher contrast, the results of which allow different models of contrast processing (e.g. energy versus gain-control models) to be critically assessed (Wichmann & Henning, 1999). Studies of detection and discrimination using pulse train stimuli in noise, on the other hand, make predictions about the number, position and properties of noise sources within the processing stream (Henning, Bird & Wichmann, 2002). Here I report modelling results combining data from both sinusoidal and pulse train experiments in and without noise to arrive at a more tightly constrained model of early spatial vision.

Wichmann, F.A., & Henning, G.B. (1999). Implications of The Pedestal Effect for Models of Contrast Processing and Gain Control. OSA Annual Meeting Program, 62.

Henning, G.B., Bird, C.M. & Wichmann, F.A. (2002). Contrast discrimination with pulse trains in pink noise. Journal of the Optical Society of America, 19, in press.