Studies on the direction of a driver’s gaze while taking a bend show that the individual looks toward the tangent-point of the inside curve. Mathematically, the direction of thispoint in relation to the car enables the driver to predict the curvature of the road. In thesame way, when a person walking in the street turns a corner, his/her gaze anticipatesthe rotation of the body. A current explanation for the visuo-motor anticipation over thelocomotion would be that the brain, involved in a steering behavior, executes an internalmodel of the trajectory that anticipates the completion of the path, and not the contrary.This paper proposes to test this hypothesis by studying the effect of an artificial manipulationof the visuo-locomotor coupling on the trajectory prediction. In this experiment,subjects remotely control a mobile robot with a pan-tilt camera. This experimental paradigmis chosen to manipulate in an easy and precise way the temporal organization of thevisuo-locomotor coupling. The results show that only the visuo-locomotor coupling organizedfrom the visual sensor to the locomotor organs enables (i) a significant smoothnessof the trajectory and (ii) a velocity-curvature relationship that follows the “2/3 Power Law.”These findings are consistent with the theory of an anticipatory construction of an internalmodel of the trajectory. This mental representation used by the brain as a forward predictionof the formation of the path seems conditioned by the motor program. The overallresults are discussed in terms of the sensorimotor scheme bases of the predictive coding.
|Journal||Frontiers in Psychology|
|Publication status||Published - 1 Jan 2012|