From Optic Flow to Laws of Control

Abstract

It is now established beyond a reasonable doubt that people can perceive self-motion from optic flow with sufficient accuracy to guide their locomotion. In particular, the direction of self-motion, or heading, can be judged quite accurately under a variety of conditions. However, as pointed out by Nakayama (1994), it remains controversial as to whether optic flow is actually used to control locomotor behavior. The aim of this chapter is to move beyond the perception of optic flow per se to the question of how a variety of information is used to control human locomotion on foot. We offer an interim report on an ongoing research program that seeks to determine the laws of control for steering and obstacle avoidance in a complex, dynamic environment. 2