A Bayesian model for the measurement of visual velocity

Several models have been proposed for how the brain measures velocity from the output of motion-energy units. These models make some unrealistic assum ptions such as the use of Gabor-shaped temporal filters, which are non caus al, or flat spatial spectra, which are invalidated by existing data. We pre sent a Bayesian model of velocity perception, which makes more realistic as sumptions and allows the estimation of local retinal velocity regardless of the specific mathematical form of the spatial and temporal filters used. T he model is consistent with several aspects of speed perception, such as th e dependence of perceived speed on contrast. (C) 2000 Elsevier Science Ltd. All rights reserved.