Mathematical analysis of motion-opponent mechanisms used in the determination of heading and depth.

A mathematical analysis is presented of a model that uses motion-opponent operators similar to neurons found in the primate middle temporal visual area, to determine observer heading and depth from optical flow information. The response of these operators to depth changes in the form of a slanted plane or a step edge is analyzed, and the outputs of odd-symmetric operators are compared with that of circularly symmetric operators. The analysis shows sources of error from these operators in determining heading and depth and suggests how some of these errors can be mitigated. Simulations are presented that show that the model performs well for a variety of situations.