The study of locomotor pointing in virtual reality: The validation of a test set-up

The goal of this experiment was to validate an experimental set-up for stud ying locomotor pointing. The specific and also original element of this set -up was the interactive nature of virtual reality and movement production. This interaction was achieved through the coupling of a treadmill and a Sil icon Graphics system. This latter system generated on a screen (3 x 2.3 m) an environmental array that moved according to the action produced by subje cts on a treadmill. The task was to place either foot on a spatial target t hat appeared on the floor in front of the subject's displacement trajectory . We analyzed the step length patterns of subjects approaching these target s, along with the current target-subject relationship. The results are in a greement with a perception-action coupling type of control mechanism that o perates continuously as the subject approaches the desired target. Apparent ly, these findings mirror observations of real-life locomotion, indicating that the present set-up provides a valid and useful tool for examining huma n locomotion.