Stochastic catastrophe analysis of switches in the perception of apparent motion.

Dynamical phenomena such as bistability and hysteresis have been found in a number of studies on perception of apparent motion. We show that new developments in stochastic catastrophe theory make it possible to test models of these phenomena empirically. Catastrophe theory explains discontinuous changes in responses caused by continuous changes in experimental parameters. We propose catastrophe models for two experimental paradigms on perception of apparent motion and present experiments that support these models. We test these models by using an algorithm for fitting stochastic catastrophe models. We derive from catastrophe theory the prediction that a dynamical phenomenon called divergence is necessary when hysteresis is found. This new prediction is supported by the data.