Absence of Inertial Load on Hand Decreases Task Performance in Virtual Reality Interaction

The inertia of manipulated objects contributes to natural human performance, but its effects on virtual reality (VR) interactions have rarely been investigated. Here, we designed a virtual goal-directed task, in which virtual objects with different masses were moved into a target hole. Based on synchronized kinematic and eye-tracking data, we examined the effects of inertia on participants’ performance during the virtual task in a virtual environment. Our results indicated that hand movements presented greater spatial variability and more discontinuities when the inertial load was removed. It suggested a decline in the ability of motor control and feedback regulation, since the absence of an inertial load weakened the proprioception for sensing limb movements. Eye-movement evidence indicated that increased preferential allocations of visual attention contribute to compensating the weakened proprioceptive cues, supporting the kinematic results. These findings reveal the importance and mechanism of inertial effects on human behaviors in VR interactions.