Object manipulations in VR show task- And object-dependent modulation of motor patterns

Abstract

Humans can perform object manipulations in VR in spite of missing haptic and acoustic information. Whether their movements under these artificial conditions do still rely on motor programs based on natural experience or are impoverished due to the restrictions imposed by VR is unclear. We investigated whether reach-to-place and reach-to-grasp movements in VR can still be adapted to the task and to the specific properties of the objects being handled, or whether they reflect a stereotypic, task- and object-independent motor program. We analyzed reach-to-grasp and reach-to-place movements from participants performing an unconstrained "set-the-table" task involving a variety of different objects in virtual reality. These actions were compared based on their kinematic features. We encountered significant differences in peak speed and the duration of the deceleration phase which are modulated depending on the action and on the manipulated object. The flexibility of natural human sensorimotor control thus is at least partially transferred and exploited in impoverished VR conditions. We discuss possible explanations of this behavior and the implications for the design of object manipulations in VR.