Studying the Effect of Display Type and Viewing Perspective on User Experience in Virtual Reality Exergames

Background: Physical inactivity has been identified as the fourth leading cause of death globally. It is now well established that a sedentary lifestyle is a unique risk factor for several diseases such as type 2 diabetes and cardiovascular disease, which account for about 30% of global mortality. Diabetes is a major preventable cause of costly and debilitating renal failure, heart disease, lower limb amputation, and avoidable blindness. In recent years, the idea of using interactive computing systems that leverage gamification to promote physical activity has been widely researched. Prior studies have shown that exergames, that is those that encourage physical activity, can increase enjoyment and intrinsic motivation compared with conventional exercises; as such, they can be effective in promoting physical and mental health. There has been some research on immersive virtual reality (VR) exergames; however, to the best of our knowledge, it is limited and preliminary. This work aims at filling the gap and investigates the effect of display type (DT) and viewing perspective (VP) on players' exertion, engagement, and overall game experience in immersive VR exergames. Objective: This article aims at examining whether DT and VP can affect gameplay performance, players' exertion, game experience, cybersickness, and electroencephalography (EEG) engagement index when playing a gesture-based (i.e., body motion) exergame. Materials and Methods: Study 1 employed a one-way between-subjects design with 24 participants equally distributed in two groups (immersive VR and 50-inch TV) to perform 12 pre-defined gestures. The main outcome measures were National Aeronautics and Space Administration-Task Load Index (NASA-TLX) workload for each group as well as 7 Likert scale and EEG engagement index for each gesture. Study 2 included 16 participants in playing a game with the gestures selected from study 1. All participants played 4 versions based on combinations of DT (immersive VR and 50-inch TV) and VP (first-person and third-person) to assess exertion (%HR_max, calories consumption, and Borg RPE 6-20), game experience, cybersickness, and EEG engagement index. Results: Study 1 results showed that DT had no effect on the ratings of the gestures, NASA-TLX workload, and EEG engagement index. Study 2 results showed that immersive VR not only resulted in a significantly higher exertion (%HR_max, calories consumption, and Borg RPE) but also helped achieve better positive game experience in challenge, flow, sensory and imaginative immersion, as well as lower negative affect. We also found that nausea and oculomotor were significantly higher in immersive VR. Conclusion: This pilot study demonstrates that youth who played gesture-based exergame in immersive VR had a higher level of exertion (%HR_max, calories consumption, and Borg RPE), although the number of performed gestures were not significantly different. They also felt that immersive VR was much more challenging, immersive (flow, sensory and imaginative immersion), and had a lower negative affect than a 50-inch TV; however, immersive VR was more likely to make youth have higher cybersickness.