Maintenance of orientation during locomotion in unfamiliar environments.

Accuracy of maintenance of orientation during locomotion in unfamiliar environments was investigated by a laboratory procedure in two experiments. In a dark room, subjects were directed to a starting point, shown a target consisting of a point light on the floor, and required to walk straight by following a moving light line (1.18 m/sec) to a stopping point 1.4 to 11.0 m away. From the stopping point, the subjects numerically estimated the direction and distance to the target, which by then was out of sight. In contrast to control conditions with the target visible, the constant and variable errors were larger, and the constant errors varied with locomotion distance in a way that suggested proportional displacements of the target in the same direction as the subjects walked. Forgetting may in part account for the errors, but the main factor was assumed to be accumulated errors in recurrent central processing of the sensory information received about locomotion distance and target location.