# Validating the Threat of a Virtual Reality Clinical Environment: A Mixed Methods Study
## 2 Materials and Methods
### VR Environments  
Subjects were placed into the VR environments via an untethered head-mounted display (Meta Quest 2, San Francisco, CA, USA) running Windows operating software (Version 11, Microsoft Corporation, Washington, DC, USA). The VR environment was rendered by a gaming laptop (ASUS TUf A15; 16 GB memory; NVIDIA GeForce RTX 3070 graphics card; AMD Ryzen 7 processor, Taipei, Taiwan) using the Unity application (Unity Applications, San Francisco, CA, USA). Data were transmitted to the head-mounted display by a wireless router (ASUS RT-AX53U, Taipei, Taiwan). A stereo image was presented on the headset screen with a 93\({}^{\circ}\) vertical field of view and 97\({}^{\circ}\) horizontal field of view, with a resolution of 1832 \(\times\) 1920, allowing subjects to survey the environment with 6 degrees of freedom. The image was updated at 90 Hz. Headset-integrated speakers relayed spatially positioned sounds of the simulations and the automated instructions.  
Three VR rooms were developed by the team at Curtin University's Hub for Immersive Visualisation and e-Research (HIVE) using the Unity application (Version 2021.3.14f1). The introduction room had a white colour scheme with simple lighting and no accompanying soundscape and was furnished with a single chair. The two experimental clinical rooms were designed to be threatening or non-threatening by the inclusion of a range of visual and auditory features. In the 'threat' VR clinical room, cool fluorescent and flickering lighting was used in conjunction with an unnatural, harsh colour scheme (i.e., red and orange [16; 17]). Subjects were exposed to mechanical noise and external voices, such as the sound of a baby crying, played through the headset [18]. The threat room furnishings included messy paperwork strewn over a desk, an overflowing rubbish bin, dead pot plants and a low-back radiograph on a computer display, which is demonstrated to induce stress [19] (Figure 2a). The 'non-threat' VR clinical room included an open window with a view to the natural environment, which also provided natural diffuse lighting and the soundscape of trees rustling and birds chirping. The room was designed with a biophilic colour scheme and contained plants, a pleasant landscape painting and children's artwork, and softer furnishings [20; 21; 22; 23; 24; 25; 26] (Figure 2b).  
Figure 1: An outline of the study protocol. Cortisol0 denotes the cortisol measurement pre-virtual reality (VR) exposure; cortisol20, 20 min post-VR exposure; cortisol26, 26 min post-VR exposure. T, threatening condition; NT, non-threatening condition. 1 QT (training only) and 2 QT, administration of the same subjective threat questionnaire. Note, subjects exited the VR room after the completion of 1 QT/2 QT.  
The VR simulation began outside the introduction room, and automated instructions asked subjects to enter and familiarise themselves with their virtual environment. Although subjects could walk around the virtual environment and immerse themselves in sights and sounds, the environments were passive, i.e., no interaction occurred. After 3 min, 1 QT was administered within the VR environment, so subjects could practice completing the virtual questionnaire. Subjects were given one minute to complete 1 QT, after which time they were asked to exit the introduction room. The subject then entered their allocated threat or non-threat VR clinical consultation room, and after 3 min, 2 QT was administered using the same interface as for 1 QT. Subjects were given one minute to complete 2 QT and then were asked to exit the experimental VR room.