UX

In this paper, we study the impact of VR input modalities (controllers vs. free-hand) on physical exertion, agency, and task performance with two mid-air interaction techniques (touch, raycast) for selection and trajectory-tracing tasks. VR controllers led to reduced physical exertion, improved control, and enhanced speed and accuracy, especially in raycast settings. Regarding personal preference, participants chose VR controllers for raycast but free-hand interaction for mid-air touch. Physical exertion increased with selection speed, quantity of arm motion, variation in motion speed, and bad postures, following ergonomics metrics such as consumed endurance and rapid upper limb assessment. Physical exertion was also negatively correlated with agency and task accuracy.

Oct 9, 2023

ViGather is an immersive teleconferencing system that integrates users of all platform types into a joint experience via equal representation and a first-person experience. ViGather renders all participants as embodied avatars in one shared scene to establish co-presence and elicit natural behavior during collocated conversations, including nonverbal communication cues such as eye contact between participants as well as body language such as turning one’s body to another person or using hand gestures to emphasize parts of a conversation during the virtual hangout.

Sep 13, 2023

InfinitePaint is a system that supports digital painting in Virtual Reality on real paper with a real wet brush. We use special paper that turns black wherever it comes into contact with water and turns blank again upon drying. A single camera captures those temporary strokes and digitizes them while applying properties like color or other digital effects. We tested our system with artists and compared the subjective experience with a drawing tablet.

Apr 26, 2023

Physiological sensing often complements studies of human behavior in virtual reality (VR) to detect users’ affective and cognitive states. Some psychological states, such as fear and frustration, can be particularly hard to differentiate from a physiological perspective as they are close in the arousal and valence emotional space. Moreover, it is largely unclear how users’ physiological reactions are expressed in response to transient psychological states such as fear, frustration, and insight—especially since these are rich indicators for characterizing users’ responses to dynamic systems but are hard to capture in highly interactive settings. We conducted a study (N=24) to analyze participants’ pulmonary, electrodermal, cardiac, and pupillary responses to moments of fear, frustration, and insight in immersive settings. Participants interacted in five VR environments, throughout which we measured their physiological reactions and analyzed the patterns. We also measured subjective fear and frustration using questionnaires.

Oct 24, 2022

Cybersickness has been one of the main impediments to the widespread adoption of Virtual Reality for decades. It has been argued that several factors can influence the occurrence of cybersickness, such as technical factors, interaction design, but also users’ demographics and their perceived presence. Yet, previous studies had comparably small sample sizes and demographically homogeneous samples; comparisons across studies (e.g., regarding demographic factors) are challenging due to the large variation in the studied virtual environments. In this paper, we address these limitations and report the results of a lab-in-the-field experiment on cybersickness with a large and heterogeneous sample of N=837 participants who navigated and interacted inside a virtual environment (ages 18–80, M=29.34, SD=9.50, 431 males, 400 females, 6 non-binaries).

Oct 20, 2022

Real-world work-spaces typically revolve around tables, which enable knowledge workers to comfortably perform tasks over an extended period of time during productivity tasks. Tables afford more ergonomic postures and provide opportunities for rest, which raises the question of whether they may also benefit prolonged interaction in Virtual Reality (VR). In this paper, we investigate the effects of tabletop surface presence in situated VR settings on task performance, behavior, and subjective experience. In an empirical study, 24 participants performed two tasks (selection, docking) on virtual interfaces placed at two distances and two orientations.

Oct 17, 2022

In this paper, we introduce the term "Affective and Cognitive VR" and its main research lines. This survey also clarifies the different models of Affective and Cognitive States (ACS), presents the methods for measuring them with their respective advantages and drawbacks in VR, and showcases Affective and Cognitive VR studies done in an Immersive Virtual Environment (IVE) in a non-clinical context. We provide a comprehensive list of references with the analysis of 63 research articles and summarize future works directions.

Sep 6, 2021

My PhD thesis aims to contribute to the development of adaptive VR systems based on the users' mental workload. We investigate 3 research axes: induction, recognition, and exploitation of mental workload in VR. In addition, we propose a definition of “Affective and Cognitive Virtual Reality”.

Jan 14, 2021

This paper describes an ``all-in-one'' solution for the real-time recognition of users' mental workloads in VR through the customization of a commercial HMD with physiological sensors. We conducted an extensive user study (N = 75) to collect mental workload data. The classification accuracy of 4 levels of mental workload using sensors embedded in the HMD is compared to the classification performance using commercial grade systems. In addition, we discuss the role of the signal normalization procedures and the contribution of the different physiological signals on the recognition accuracy.

Nov 6, 2020

In this paper, we propose to consider Mental Workload (MWL) for the design of complex training scenarios involving multiple parallel tasks in VR. The proposed approach is based on the assessment of the MWL elicited by each potential task configuration in the training application. Following the assessment, the resulting model is then used to create training scenarios able to modulate the user’s MWL over time. This approach is illustrated by a VR flight training simulator based on the Multi-Attribute Task Battery II. Two user studies (Ntot = 52) confirmed that the approach was able to induce the expected mental workload over time.

Mar 6, 2020