The authors of this paper sought to investigate the impact of virtual forest therapy based on realistic versus dreamlike environments on reducing stress levels. Today, people are facing an increase in stress levels in everyday life, which may be due to personal life, work environment, or urban area expansion. Previous studies have reported that urban environments demand more attention and mental workload than natural environments. However, evidence for the effects of natural environments as virtual forest therapy on stress levels has not yet been fully explored. In this study, a total of 20 healthy participants completed a letter-detection test to increase their stress level and were then randomly assigned to two different virtual environments representing realistic and dreamlike graphics. The participants’ stress levels were assessed using two physiological methods that measured heart rate and skin conductance levels and one psychological method through the Profile of Mood States (POMS) questionnaire. These indicators were analyzed using a sample t-test and a one-way analysis of variance. The results showed that virtual forest environments could have positive stress-relieving effects. However, realistic graphics were more efficient in reducing stress. These findings contribute to growing forest therapy concepts and provide new directions for future forest therapy research.

This study aims to analyze differences between a CAVE system and a Head-Mounted Display (HMD), two technologies presenting important differences, focusing on distance perception, as past research on this factor is usually carried with only one or the other device. We performed two experiments. First, we explored the impact of the HMD's weight, by removing any other bias. Second, we compared distance perception using a simple hand interaction in a replicated environment. Results reveal that the HMD's weight has no significant impact over short distances, and the usage of a virtual replica was found to improve distance perception.

This paper proposes to analyse user experience using two different immersive device categories: a cave automatic virtual environment (CAVE) and a head-mounted display (HMD). While most past studies focused on one of these devices to characterize user experience, we propose to fill the gap in comparative studies by conducting investigations using both devices, considering the same application, method and analysis. Through this study, we want to highlight the differences in user experience induced when using either one of these technologies in terms of visualization and interaction. We performed two experiments, each focusing on a specific aspect of the devices employed. The first one is related to distance perception when walking and the possible influence of the HMD’s weight, which does not occur with CAVE systems as they do not require wearing any heavy equipment. Past studies found that weight may impact distance perception. Several walking distances were considered. Results revealed that the HMD’s weight does not induce significant differences over short distances (above three meters). In the second experiment, we focused on distance perception over short distances. We considered that the HMD’s screen being closer to the user’s eyes than in CAVE systems might induce substantial distance perception differences, especially for short-distance interaction. We designed a task in which users had to move an object from one place to another at several distances using the CAVE and an HMD. Results revealed significant underestimation compared to reality as in past work, but no significant differences between the immersive devices. These results provide a better understanding of the differences between the two emblematic virtual reality displays.