Virtual reality (VR)
HMD
The patients wore a head-mounted display (HMD) with continuous tracking of head rotation and interindividual adjusted inter-pupillary distance (Oculus Rift CV1; Oculus VR, Inc., Menlo Park, USA). Both screens of the HMD had a resolution of 1080 × 1200 pixels. The virtual environment was built and controlled by Unity 3D (5.6.2f1) with a bundled version of OVRPlugin. Trajectories of the patients’ hand were tracked by a near-infrared sensor (Leap Motion Inc., San Francisco, USA) and were streamed in real-time into the HMD. Thus, the patients could interact with the virtual stimuli by actual movements of their hand. The sensor was placed on a small table in front of the patients and covered a range of approximately 1600 cm