Visual information processing in direct collision course - a simple computational model

In the research of direct collision course, the computation of TTC, time to collision, is thought subjectively an important critical criteria. Formula /spl tau/ /spl ap/ /spl theta///spl theta/' was usually utilized to calculate TTC where /spl theta/ is the visual angle subtended by the looming object and /spl theta/' is the derivative of /spl theta/ over time. In this paper, we found that 1//spl tau/ can also be approximated by using a weighted combination of 1/(/spl theta/+B) and /spl theta/, where B is a constant. We then built a simple computational model by including an improved back propagation algorithm as a way of simulating the brain response patterns. The accurate estimation of TTC, relative definite physiological meaning of the hidden neurons, and the good plasticity and robustness of the model imply that it is a potential and realizable model and is very likely to imitate the physiological brain mechanism of the visual information processing in the direct collision course.