Force Control During the Precision Grip Translates to Virtual Reality

When grasping and manipulating objects we implicitly adapt grip forces according to the physical parameters of the object. We integrate visual, cutaneous, and force feedback to estimate these parameters and adapt our control accordingly. Using virtual reality, both feedback integration and control can be investigated in ways that are not possible using real-life objects. Here, we present our custom-built virtual reality setup and show its validity for use in human studies of fine motor control. Participants grasped and lifted virtual objects with different weights. We show that, consistent with lifting real objects, all participants adapt their grip forces to the object mass, and do so on a trial-by-trial basis. Compared to similar studies with real objects and full feedback, grip forces were increased, and adaptation required more trials. This study successfully demonstrated that grip force control in the precision grip translates to virtual reality. While our setup can be used for similar work in the future, subsequent virtual reality experiments should include a longer adaptation phase compared to classic setups.