This demo presents an innovative and validated method for measuring interpersonal trust in virtual humans as social interaction partners. In our design, participants are tasked to navigate through a virtual reality maze and interact with a virtual human, seeking advice on which path to take. By carefully designing the experiments and context, we induced participants to believe that they are interacting with a real person. A validation study, manipulating virtual humans' appearance, tone of voice, and engagement, revealed that the frequency of advice-seeking in the maze correlates with participants' evaluation of interpersonal trust towards virtual humans. Thus, our paradigm represents a valuable research tool for studying trust in virtual reality.

Virtual humans, including virtual agents and avatars, play an increasingly important role as VR technology advances. For example, virtual humans are used as digital bodies of users in social VR or as interfaces for AI assistants in online financing. Interpersonal trust is an essential prerequisite in real-life interactions, as well as in the virtual world. However, to date, there are no established interpersonal trust measurement tools specifically for virtual humans in virtual reality. This study fills the gap, by contributing a novel validated behavioural tool to measure interpersonal trust towards a specific virtual social interaction partner in social VR. This validated paradigm is inspired by a previously proposed virtual maze task that measures trust towards virtual characters. In the current study, a variant of this paradigm was implemented. The task of the users (the trustors) is to navigate through a maze in virtual reality, where they can interact with a virtual human (the trustee). They can choose to 1) ask for advice and 2) follow the advice from the virtual human if they want to. These measures served as behavioural measures of trust. We conducted a validation study with 70 participants in a between-subject design. The two conditions did not differ in the content of the advice but in the appearance, tone of voice and engagement of the trustees (alleged as avatars controlled by other participants). Results indicate that the experimental manipulation was successful, as participants rated the virtual human as more trustworthy in the trustworthy condition than in the untrustworthy condition. Importantly, this manipulation affected the trust behaviour of our participants, who, in the trustworthy condition, asked for advice more often and followed advice more often, indicating that the paradigm is sensitive to assessing interpersonal trust towards virtual humans. Thus, our paradigm can be used to measure differences in interpersonal trust towards virtual humans and may serve as a valuable research tool to study trust in virtual reality.

Photorealistic avatars show great potential in social VR and VR collaboration. However, identity and privacy issues are threatening avatars' authenticity in social VR. In addition to the necessary authentication and protection, effective solutions are needed to convey avatars' authenticity status to users and thereby enhance the overall trustworthiness. We designed several visual indicators (VIs) using static or dynamic visual effects on photorealistic avatars and evaluated their effectiveness in visualizing avatars' authenticity status. In this study we explored suitable attributes and designs for conveying the authenticity of photorealistic avatars and influencing their perceived trustworthiness. Furthermore, we investigated how different interactivity levels influence their effectiveness (the avatar was either presented in a static image, an animated video clip, or an immersive virtual environment). Our findings showed that using a full name can increase trust, while most other VIs could decrease users' trust. We also found that interactivity levels significantly impacted users' trust and the effectiveness of VIs. Based on our results, we developed design guidelines for visual indicators as effective tools to convey authenticity, as a first step towards the improvement of trustworthiness in social VR with identity management.

Virtual Reality (VR) technology offers promising opportunities to improve traditional treadmill-based rehabilitation programs. We present an immersive VR rehabilitation system that includes a head-mounted display and motion sensors. The application is designed to promote the experience of relatedness, autonomy, and competence. The application uses procedural content generation to generate diverse landscapes. We evaluated the effect of the immersive rehabilitation system on motivation and affect. We conducted a repeated measures study with 36 healthy participants to compare the immersive program to a traditional rehabilitation program. Participants reported significant greater enjoyment, felt more competent and experienced higher decision freedom and meaningfulness in the immersive VR gait training compared to the traditional training. They experienced significantly lower physical demand, simulator sickness, and state anxiety, and felt less pressured while still perceiving a higher personal performance. We derive three design implications for future applications in gait rehabilitation: Immersive VR provides a promising augmentation for gait rehabilitation. Gamification features provide a design guideline for content creation in gait rehabilitation. Relatedness and autonomy provide critical content features in gait rehabilitation.

Virtual reality (VR) has become a popular approach to study human behavior in fire.The present position paper analyses Strengths, Weaknesses, Opportunities, and Threats (SWOT) of VR as a research tool for human behavior in fire.Virtual environments provide a maximum of experimental control, are easy to replicate, have relatively high ecological validity, and allow safe study of occupant behavior in scenarios that otherwise would be too dangerous.Lower ecological validity compared to field studies, ergonomic aspects, and technical limitations are the main weaknesses of the method.Increasingly realistic simulations and other technological advances provide new opportunities for this relatively young method.In this position paper, we argue that VR is a promising complementary laboratory tool in the quest to understand human behavior in fire and to improve fire safety.