Wiener analysis of grating contrast judgments

Wiener's method of nonlinear system identification is modified to allow it to be used for the first time to analyze data obtained from systems where the stimulus is a spatial waveform and the response is a single number, such as in contrast-matching experiments. Data from models and experiments were analyzed in the spatial-frequency, rather than the spatial domain. First and second order kernels obtained from experimental data agreed with those of a model containing parallel frequency-selective channels. Each channel consisted of a linear filter followed by a nonlinear transducer function: the channel outputs were linearly summed. The first order kernels also agreed well with a sine-wave sensitivity function obtained by conventional methods.