# Usability and Affects Study of a Virtual Reality System Toward Scorpion Phobia Exposure Therapy
## 4 Discussion  
Part of the main contribution of this work is the usability and affects study to examine user experiences of undergoing virtual reality system toward scorpion phobia exposure therapy with real-time biofeedback. Using the System Usability Scale and the Positive and Negative Affect Schedule, we evaluated a non-clinical sample of undergraduate students. The system is proposed as a support tool for psychologists to optimize resources and take advantage of the benefits of VRET. This work provides evidence that it is possible to realistically replace live exhibits with virtual models for specific phobias. Furthermore, this research aims to systematically develop a VRET platform using a MEDEERV-based framework [41]. This framework could used to develop scalable virtual environments; not only VRET but virtual reality environments in general. Several papers have presented studies on VRET for specific phobias, with some studies related to VRET for arachnids. PhoByeVR is an interesting innovative educational tool for managing fear that targets arachnophobia, ophidiophobia, and acrophobia [20]. For arachnophobia, they manage the levels of exposure depending on the scene. The first level is a room with pictures on the wall and videos of spiders, in level 2 there is a VR head set with PC components to display the use of 360\({}^{\circ}\) videos, level 3 is a room with a terrarium, and level 4 has a miniature jungle. In our case, we use a virtual psychotherapeutic room that has three levels according to the BAT based on the proximity distance, between the participant and the scorpion. In terms of testing, PhoByeVR was tested within a single case study with a single participant who reported a medium intensity of phobia, making it necessary to test with a larger population. For our part, we tested with a nonclinical sample of more than 50 participants. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Level** & **Mean** & **SD** \\ \hline L1 & 84.08 & 10.10 \\ L2 & 84.07 & 8.32 \\ L3 & 84.33 & 8.59 \\ \hline Total & 84.01 & 7.81 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Mean and standard deviation (SD) biofeedback heart rate (BPM) for the three levels for the participants. In association with other works, Think+ is a mobile game application to treat different phobias [70]. The three level games of Think+ are related to the collection of stars containing spiders. Although they report that the game can be applied successfully on a psychotherapeutic basis, its main limitation is its lack of realism. Quite a complete work has been presented in [25], of which the objective was to check, among other things, whether VR participants were able to approach a real tarantula to a greater extent than non-VR participants. There was no indication that participants in the VR condition were able to approach a real-life spider to a greater extent than the non-VR group. Although it was not a treatment study as in this work, one limitation is that fear of spiders was not reassessed at a later stage, which does not present evidence of the treatment effect. The VRET-AP is a recent tool for the one-session treatment of arachnophobia [19], VRET-AP has been used as a feasibility study for exposure therapy, but with spiders and not scorptions. A limitation of this work is that the system was tested with 11 participants. In a novel way, ref. [71] propose a framework for VRET utilizing procedural content generation (PCG) and reinforcement learning (RL), demonstrating a higher performance of the system compared to more common rule-based VRET methods. Two scenarios of exposure to relaxing and anxious spiders were used. Furthermore, its implementation within controlled conditions does not indicate that the system is currently ready for clinical applications. Furthermore, the relatively small sample size may not fully capture the variety of responses. Few studies have developed direct experiments to evaluate usability, focusing more on the functionality of VRET than its usability.