'Pinch' Task. A) View of starting position for 'Pinch' including PHANToM device configuration used to calibrate the coordinate system in the virtual environment. Index finger and thumb were held 7 cm apart and parallel to the table. B) View of 'Pinch' scene. Initially, the task required the subject to pick up a cube and place it into a window on the back wall of an enclosed room. Due to technical difficulties, the task was modified. In the new version, the participant picks the object up from the floor, lifts it to a specified height, and places it back on the floor with control. Haptic feedback is provided to both fingers via the PHANToM devices such that the participant has the sense of lifting a real object with mass. There were 10 trials per block; each trial was configured using 8 parameters: cube width (20–40 mm); cube height (20–40 mm); cube length (20–40 mm); mass (50–150 g); dynamic friction (0.5–1.0); static friction (0.5–1.0); stiffness (0.5–1.0); and lift height (20–80 mm). A maximum of 30 seconds was allowed for each trial.