scholarly journals Judgments of Object Size and Distance across Different Virtual Reality Environments: A Preliminary Study

2021 ◽  
Vol 11 (23) ◽  
pp. 11510
Author(s):  
Hannah Park ◽  
Nafiseh Faghihi ◽  
Manish Dixit ◽  
Jyotsna Vaid ◽  
Ann McNamara

Emerging technologies offer the potential to expand the domain of the future workforce to extreme environments, such as outer space and alien terrains. To understand how humans navigate in such environments that lack familiar spatial cues this study examined spatial perception in three types of environments. The environments were simulated using virtual reality. We examined participants’ ability to estimate the size and distance of stimuli under conditions of minimal, moderate, or maximum visual cues, corresponding to an environment simulating outer space, an alien terrain, or a typical cityscape, respectively. The findings show underestimation of distance in both the maximum and the minimum visual cue environment but a tendency for overestimation of distance in the moderate environment. We further observed that depth estimation was substantially better in the minimum environment than in the other two environments. However, estimation of height was more accurate in the environment with maximum cues (cityscape) than the environment with minimum cues (outer space). More generally, our results suggest that familiar visual cues facilitated better estimation of size and distance than unfamiliar cues. In fact, the presence of unfamiliar, and perhaps misleading visual cues (characterizing the alien terrain environment), was more disruptive than an environment with a total absence of visual cues for distance and size perception. The findings have implications for training workers to better adapt to extreme environments.

Author(s):  
Robin Horst ◽  
Ramtin Naraghi-Taghi-Off ◽  
Linda Rau ◽  
Ralf Dörner

AbstractEvery Virtual Reality (VR) experience has to end at some point. While there already exist concepts to design transitions for users to enter a virtual world, their return from the physical world should be considered, as well, as it is a part of the overall VR experience. We call the latter outro-transitions. In contrast to offboarding of VR experiences, that takes place after taking off VR hardware (e.g., HMDs), outro-transitions are still part of the immersive experience. Such transitions occur more frequently when VR is experienced periodically and for only short times. One example where transition techniques are necessary is in an auditorium where the audience has individual VR headsets available, for example, in a presentation using PowerPoint slides together with brief VR experiences sprinkled between the slides. The audience must put on and take off HMDs frequently every time they switch from common presentation media to VR and back. In a such a one-to-many VR scenario, it is challenging for presenters to explore the process of multiple people coming back from the virtual to the physical world at once. Direct communication may be constrained while VR users are wearing an HMD. Presenters need a tool to indicate them to stop the VR session and switch back to the slide presentation. Virtual visual cues can help presenters or other external entities (e.g., automated/scripted events) to request VR users to end a VR session. Such transitions become part of the overall experience of the audience and thus must be considered. This paper explores visual cues as outro-transitions from a virtual world back to the physical world and their utility to enable presenters to request VR users to end a VR session. We propose and investigate eight transition techniques. We focus on their usage in short consecutive VR experiences and include both established and novel techniques. The transition techniques are evaluated within a user study to draw conclusions on the effects of outro-transitions on the overall experience and presence of participants. We also take into account how long an outro-transition may take and how comfortable our participants perceived the proposed techniques. The study points out that they preferred non-interactive outro-transitions over interactive ones, except for a transition that allowed VR users to communicate with presenters. Furthermore, we explore the presenter-VR user relation within a presentation scenario that uses short VR experiences. The study indicates involving presenters that can stop a VR session was not only negligible but preferred by our participants.


2017 ◽  
Vol 56 (2) ◽  
pp. 619-627 ◽  
Author(s):  
Stelios Zygouris ◽  
Konstantinos Ntovas ◽  
Dimitrios Giakoumis ◽  
Konstantinos Votis ◽  
Stefanos Doumpoulakis ◽  
...  

2021 ◽  
Vol 2 ◽  
Author(s):  
Charlotte Croucher ◽  
Wendy Powell ◽  
Matt Dicks ◽  
Brett Stevens ◽  
Vaughan Powell

Virtual reality is increasingly used in rehabilitation and can provide additional motivation when working toward therapeutic goals. However, a particular problem for patients regards their ability to plan routes in unfamiliar environments. Therefore, the aim of this study was to explore how visual cues, namely embedded context-sensitive attractors, can guide attention and walking direction in VR, for clinical walking interventions. This study was designed using a butterfly as the embedded context-sensitive attractor, to guide participant locomotion around the clinical figure of eight walk test, to limit the use of verbal instructions. We investigated the effect of varying the number of attractors for figure of eight path following, and whether there are any negative impacts on perceived autonomy or workload. A total of 24 participants took part in the study and completed six attractor conditions in a counterbalanced order. They also experienced a control VE (no attractors) at the beginning and end of the protocol. Each VE condition lasted a duration of 1 min and manipulated the number of attractors to either singular or multiple alongside, the placement of turning markers (virtual trees) used to represent the cones used in clinical settings for the figure of eight walk test. Results suggested that embedded context-sensitive attractors can be used to guide walking direction, following a figure of eight in VR without impacting perceived autonomy, and workload. However, there appears to be a saturation point, with regards to effectiveness of attractors. Too few objects in a VE may reduce feelings of intrinsic motivation, and too many objects in a VE may reduce the effectiveness of attractors for guiding individuals along a figure of eight path. We conclude by indicating future research directions, for attractors and their use as a guide for walking direction.


2001 ◽  
Vol 5 (1) ◽  
pp. 146-156
Author(s):  
Giuseppe Riva

The paper presents an overview of the ergonomic/design issues of a VR-enhanced orthopaedic appliance to be used in rehabilitation of patients with Spinal Cord Injury. First, some design considerations are described and an outline of aims which the tool should pursue are given. Finally, the design issues are described focusing both on the development of a test-bed rehabilitation device and on the description of a preliminary study detailing the use of the device with a long-term SCI patient. The basis for this approach is that physical therapy and motivation are crucial for maintaining flexibility and muscle strength and for reorganizing the nervous system after SCIs.


PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0242416
Author(s):  
Salomé Le Franc ◽  
Mathis Fleury ◽  
Mélanie Cogne ◽  
Simon Butet ◽  
Christian Barillot ◽  
...  

Introduction Illusion of movement induced by tendon vibration is an effective approach for motor and sensory rehabilitation in case of neurological impairments. The aim of our study was to investigate which modality of visual feedback in Virtual Reality (VR) associated with tendon vibration of the wrist could induce the best illusion of movement. Methods We included 30 healthy participants in the experiment. Tendon vibration inducing illusion of movement (wrist extension, 100Hz) was applied on their wrist during 3 VR visual conditions (10 times each): a moving virtual hand corresponding to the movement that the participants could feel during the tendon vibration (Moving condition), a static virtual hand (Static condition), or no virtual hand at all (Hidden condition). After each trial, the participants had to quantify the intensity of the illusory movement on a Likert scale, the subjective degree of extension of their wrist and afterwards they answered a questionnaire. Results There was a significant difference between the 3 visual feedback conditions concerning the Likert scale ranking and the degree of wrist’s extension (p<0.001). The Moving condition induced a higher intensity of illusion of movement and a higher sensation of wrist’s extension than the Hidden condition (p<0.001 and p<0.001 respectively) than that of the Static condition (p<0.001 and p<0.001 respectively). The Hidden condition also induced a higher intensity of illusion of movement and a higher sensation of wrist’s extension than the Static condition (p<0.01 and p<0.01 respectively). The preferred condition to facilitate movement’s illusion was the Moving condition (63.3%). Conclusions This study demonstrated the importance of carefully selecting a visual feedback to improve the illusion of movement induced by tendon vibration, and the increase of illusion by adding VR visual cues congruent to the illusion of movement. Further work will consist in testing the same hypothesis with stroke patients.


2021 ◽  
Vol 2 ◽  
Author(s):  
Thirsa Huisman ◽  
Axel Ahrens ◽  
Ewen MacDonald

To reproduce realistic audio-visual scenarios in the laboratory, Ambisonics is often used to reproduce a sound field over loudspeakers and virtual reality (VR) glasses are used to present visual information. Both technologies have been shown to be suitable for research. However, the combination of both technologies, Ambisonics and VR glasses, might affect the spatial cues for auditory localization and thus, the localization percept. Here, we investigated how VR glasses affect the localization of virtual sound sources on the horizontal plane produced using either 1st-, 3rd-, 5th- or 11th-order Ambisonics with and without visual information. Results showed that with 1st-order Ambisonics the localization error is larger than with the higher orders, while the differences across the higher orders were small. The physical presence of the VR glasses without visual information increased the perceived lateralization of the auditory stimuli by on average about 2°, especially in the right hemisphere. Presenting visual information about the environment and potential sound sources did reduce this HMD-induced shift, however it could not fully compensate for it. While the localization performance itself was affected by the Ambisonics order, there was no interaction between the Ambisonics order and the effect of the HMD. Thus, the presence of VR glasses can alter acoustic localization when using Ambisonics sound reproduction, but visual information can compensate for most of the effects. As such, most use cases for VR will be unaffected by these shifts in the perceived location of the auditory stimuli.


Author(s):  
Margaret R. Tarampi ◽  
Michael N. Geuss ◽  
Jeanine K. Stefanucci ◽  
Sarah H. Creem-Regehr

Author(s):  
Thea Andersen ◽  
Gintare Anisimovaite ◽  
Anders Christiansen ◽  
Mohamed Hussein ◽  
Carol Lund ◽  
...  

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