Embodying photorealistic personalized avatars that closely resemble their users has recently become technologically achievable in virtual reality (VR). While previous work highlighted several benefits of personalization, its impact on emotions, a central VR element, remains underexplored. Given their high production cost, assessing the added value of photorealistic personalized avatars is essential before their adoption as a design feature. To address this, we designed and validated (n=302) four virtual environments (VEs) that induce emotions in different quadrants of Russell’s Circumplex Model. Using these VEs, we systematically investigated the impact of avatar type (no avatar, generic avatar, personalized avatar) on perceived emotions and physiological responses (n=51). Generic avatars enhanced valence, arousal, embodiment, presence and selected physiological measures, while personalized avatars further amplified these effects and additionally increased heart rate variability, a marker of self-regulation. Our study demonstrates that photorealistic personalized avatars markedly enhance VR’s capacity to foster emotional engagement.

Despite the growing adoption of freehand interactions in virtual reality (VR), the accessibility of default gesture implementations for individuals with upper limb motor impairments remains largely unexamined.To investigate unique accessibility challenges, we recruited adults with upper limb impairments (n=8) and a control group (n=16).We captured subjective and objective measures of impairment before participants performed common freehand interactions in VR including pinching, grasping, pressing, swiping and scrolling.Through observational analyses and semi-structured interviews, we identified usability barriers.Our findings reveal that even when gestures are functionally possible, restrictive implementations cause pain and fatigue for users with impairments.In particular, pinching -widely used in state-of-the-art systemsrelies heavily on the index finger, while both pinching and grasping are often defined by rigid performance thresholds.These factors exacerbate accessibility issues, especially when paired with the limitations of current tracking technologies.These insights highlight critical gaps in current design considerations and lay the foundation for developing more inclusive freehand interaction systems that reduce pain and better support a range of motor abilities.

Virtual Reality (VR) designers and researchers often need to measure emotions and presence as they evolve over time. The experience sampling method (ESM) is a common way to achieve this, however, ESM disrupts the experience and lacks granularity. We propose \tool{}, a new method for measuring subjective emotions and presence in VR, where users watch back their VR experience and retrospectively sketch a plot of their feelings. RetroSketch leaves the VR experience undisturbed and yields highly granular data, including information about salient events and qualitative descriptions of their feelings. We compared RetroSketch and ESM in a large study (n=140) using five different VR experiences over one-hour sessions. Our results show that RetroSketch and ESM measures are highly correlated with each other, as well as physiological measures indicative of emotion. The correlations are robust across different VR experiences and user demographics. They also highlight the impact of ESM on users' experience.

Healthcare artificial intelligence (HAI) robots could alleviate the current healthcare provision crisis. However, their successful deployment rests on achieving and responsibly calibrating appropriate patient trust in them. Over two user studies, we systematically investigate trust formation in and usage intentions for HAI robots. We first investigate manipulations of visual appearance in a passive observation study without healthcare-specific situational context (n=87) and then in a realistic VR scenario depicting a medical consultation with a HAI robot (n=177) that introduces such situational context (diagnosis and treatment severity). Results show that within a healthcare context, a unique combination of (i) situational (diagnosis and treatment severity), (ii) robot (perceived competence) and (iii) user characteristics (personality and attitudes) determine trust and ultimately influence usage intentions for HAI robots. Furthermore, our results emphasize the absence of HAI visual appearance effects on trust. Our findings support and inform a human centred design approach of HAI robots.

There is great potential for adapting Virtual Reality (VR) exergames based on a user’s affective state. However, physical activity and VR interfere with physiological sensors, making affect recognition challenging. We conducted a study (n=72) in which users experienced four emotion inducing VR exergaming environments (happiness, sadness, stress and calmness) at three different levels of exertion (low, medium, high). We collected physiological measures through pupillometry, electrodermal activity, heart rate, and facial tracking, as well as subjective affect ratings. Our validated virtual environments, data, and analyses are openly available. We found that the level of exertion influences the way affect can be recognised, as well as affect itself. Furthermore, our results highlight the importance of data cleaning to account for environmental and interpersonal factors interfering with physiological measures. The results shed light on the relationships between physiological measures and affective states and inform design choices about sensors and data cleaning approaches for affective VR.

Surfaces with deformable and shape-changing properties seek to enhance and diversify tangible interactions with computing systems. However, we currently lack fundamental knowledge and user interface design principles that connect the inherent properties of deformable shapes with our human senses and cognitive associations. To address this knowledge gap, we systematically explored deformable shapes’ cross-modal correspondences (CC) with colours and emotions. In our CC study, 52 participants were presented with deformable shape stimuli that varied in stiffness and angularity. They were asked to associate these stimuli with colours and emotions under (i) visuo-tactile and; (ii) tactile-only conditions. For the first time, our findings reveal (1) how stiffness level primarily influences the CC associations and; (2) that stiffness and angularity play a significant role in CC associations over the visibility of the shapes. The results were distilled into design guidelines for future deformable, shape-changing interfaces that engage specific human senses and responses.

Shows such as The Mandalorian have used Virtual Production (VP) to great creative advantage. This combination, of tracked cameras and virtual environments, gives film crews the flexibility to rapidly iterate ideas and discover the best telling of their story within the time constraints of movie production. We explore if the same ideas can translate to pre-production, specifically if similar advantages can be found during the storyboarding phase. Developing a novel virtual production interface named Camera Chameleon, we compare user interaction against traditional keyboard/mouse peripherals when creating storyboards. Similar expert-rated quality is measured on storyboard output, however, users report increased enjoyment and complete shots more quickly. Novice users explore more when using our approach, demonstrating its creative potential.

Co-located social gaming with players and observers talking to each other is commonplace. However, it becomes less attractive when using virtual reality (VR): while VR increases players’ presence by immersing them in a virtual world, it also shuts out their observing friends. We investigate whether extended reality (XR) can improve the observer experience by giving them agency over their viewpoint in the game and personalizing the representation they see of the player. In a user study, 24 pairs of players and observers experienced co-located VR gaming. Observers either watched the player’s gameplay on a stationary screen i) from the player’s viewpoint or ii) controlling their viewpoint with a gamepad, or on an XR-enabled mobile screen controlling their viewpoint by moving the screen iii) with the player represented as a generic game avatar or iv) a personalized avatar obtained through live player footage augmentation. Results show that giving observers agency over their viewpoint with an XR-enabled mobile screen provides substantial benefits to presence and observers’ overall experience.

Presence is one of the most studied and most important variables in immersive virtual reality (VR) and it influences the effectiveness of many VR applications. Separate bodies of research indicate that presence is determined by (1) technical factors such as the visual realism of a virtual environment (VE) and the field of view (FoV), and (2) human factors such as emotions and agency. However, it remains unknown how technical and human factors may interact in the presence formation process. We conducted a user study (n=360) to investigate the effects of visual realism (high/low), FoV (high/low), emotions (focusing on fear) and agency (yes/no) on presence. Counter to previous assumptions, technical factors did not affect presence directly but were moderated through human factors. We propose TAP-Fear, a structural equation model that describes how design decisions, technical factors and human factors combine and interact in the formation of presence.

Personality characteristics can affect how much presence an individual experiences in virtual reality, and researchers have explored how it may be possible to prime users to increase their sense of presence. A personality characteristic that has yet to be explored in the VR literature is imaginative suggestibility, the ability of an individual to successfully experience an imaginary scenario as if it were real. In this paper, we explore how suggestibility and priming affect presence when consulting an ancient oracle in VR as part of an educational experience – a common VR application. We show for the first time how imaginative suggestibility is a major factor which affects presence and emotions experienced in VR, while priming cues have no effect on participants’ (n=128) user experience, contrasting results from prior work. We consider the impacts of these findings for VR design and provide guidelines based on our results.

Deformable interfaces provide unique interaction potential for force input, for example, when users physically push into a soft display surface. However, there remains limited understanding of which visual-tactile design elements signify the presence and stiffness of such deformable force-input components. In this paper, we explore how people correspond surface stiffness to colours, graphical shapes, and physical shapes. We conducted a cross-modal correspondence (CC) study, where 30 participants associated different surface stiffnesses with colours and shapes. Our findings evidence the CCs between stiffness levels for a subset of the 2D/3D shapes and colours used in the study. We distil our findings in three design recommendations: (1) lighter colours should be used to indicate soft surfaces, and darker colours should indicate stiff surfaces; (2) rounded shapes should be used to indicate soft surfaces, while less-curved shapes should be used to indicate stiffer surfaces, and; (3) longer 2D drop-shadows should be used to indicate softer surfaces, while shorter drop-shadows should be used to indicate stiffer surfaces.

Street harassment is a widespread problem that can constrain people’s freedom to enjoy public spaces safely, along with many other negative psychological impacts. However, very little research has looked at how immersive technology can help in addressing it. We conducted three studies to investigate the design decisions, ethical issues and efficacy of an immersive simulation of street harassment: an online design study (n=20), an interview study with experts working in the area (n=9), and a comparative lab study investigating design, ethics and efficacy (n=44). Our results deepen understanding of the design decisions that contribute to a realistic psychological experience, such as the effects of screen-based video vs passive VR vs interactive VR. They also highlight important ethical issues such as traumatisation and potential for victim blaming, and how they can be approached in an ethical manner. Finally, they provide insights into efficacy in terms of perceived usefulness, competence and empathy.

Arguably one of the most important characteristics of virtual reality (VR) is its ability to induce higher feelings of presence. Still, research has remained inconclusive on how presence is affected by human factors such as emotion and agency. Here we adopt a novel design to investigate their effects by testing virtual environments inducing either happiness or fear, with or without user agency. Results from 121 participants showed that the dominant emotion induced by a virtual environment is positively correlated with presence. In addition, agency had a significant positive effect on presence and, furthermore, moderated the effect of emotion on presence. We show for the first time that the effects of emotion and agency on presence are not straightforward but they can be modelled by separating design factors from subjective measures. We discuss how these findings can explain seemingly conflicting results of related work and their implications for VR design.