Visually controlled locomotion: Its dependence on optic flow, three-dimensional space perception, and cognition

Gibson (1958/this issue) and his followers have emphasized the role of opti c flow in the control of locomotion. In recent years much research has been devoted to the visual control of aiming and braking, mainly in connection with terrestrial locomotion. The goal of this article is to broaden the top ic empirically and theoretically. At the empirical level, we argue that the re are a number of visually controlled maneuvers that need to be addressed for their own sake, for they involve more than can be learned from research on aiming and braking. At the theoretical level, we argue that optic flow needs to be supplemented by other explanatory primitives, including the act or's perception of three dimensional spatial layout and the actor's cogniti ve representations of the spatial envelope and plant dynamics of his or her body or vehicle.