Motion detectors and motion segregation

The response of motion detectors necessarily confound image velocity with image structure. In particular, even a rigidly moving image (with a uniform velocity field) will give rise to non-uniform detector responses. A mathematical framework has been proposed on how to intrinsically compare motion detectors' responses so that their differences will reflect the true differences in image velocity (Zhang and Wu, Proc. Natl. Acad. Sci. USA 87, 7819-7823, 1990). Here, this notion of 'intrinsic differentiation' was implemented by introducing a gamma-matrix determined by the image spatial gradients. The perceptual phenomenon of random-dot motion segregation was successfully simulated.