Abstract
Human behavior is often coordinated with rhythmic environmental information, such as timing one’s movement based on the visual information available to board an escalator. Previous research suggests that, in human-environment systems, certain environmental factors act as control parameters for the guidance of action. The current study employed an immersive virtual environment within which participants were asked to retrieve a target ball from a virtual box with two sliding doors that oscillated at a different frequency in each trial. To be successful, participants had to avoid colliding with the moving doors as they retrieved the ball. We investigated the coupling between the participants’ hand movement and the oscillating sliding doors. Throughout the experiment, participants saw one of three end-effectors: a) a virtual controller that was yoked to a real hand-held controller, b) a virtual hand that was yoked to the same hand-held controller, or c) a virtual hand that was yoked to a hand-tracked glove. The type of virtual end-effector used was a between-subjects factor. Cross recurrence quantification analysis was performed on the hand and door trajectories for each participant to measure the coordination between the hand and the doors while retrieving the ball. Frequency of oscillation of the doors was identified as the control parameter. The results indicate that, as the door frequency increased, coupling between the hand and the door reduced significantly. The rate of reduction in coupling was much higher for participants who saw the glove-yoked virtual hand as the end-effector. Reduced coupling also resulted in more successful retrieval at higher door oscillation frequencies. The results have implications on the type of end-effector designed for rhythmic tasks in virtual reality. These findings also suggest ways to train people in such tasks for improved performance.