Head-mounted Display Condition Research Articles

Motion Sickness during Roll Motion: VR HMD View versus Monitor View

The purpose of this study was to investigate the effect of two views on motion sickness caused by low-frequency roll motion in the laboratory. Fifteen healthy male subjects participated in the study and were exposed to 30 min of 0.25 Hz roll oscillation at an angle of rotation (±5°). Subjects sat on a rigid seat with one of two visual scenes each session: (i) viewing 360° videos through virtual reality (VR) head-mounted display (HMD) device and (ii) reading articles on a monitor in a closed cabin. Ratings of motion sickness were obtained at 1 min intervals. The mean illness ratings of subjects for all visual conditions increased over the 30 min exposure to motion. There was significantly less sickness in the HMD condition than in the monitor condition. The findings suggest a beneficial effect of the HMD view on the severity of sickness. However, the HMD view had no effect on the sickness experienced by those vulnerable to sickness caused by exposure to motion or use of VR. It was concluded that the visual activity had a significant influence on motion sickness induced by 0.25 Hz roll oscillation with an angle of rotation (±5°), and the applications of VR could be implemented to further reduce motion sickness.

The Effects of Acute Virtual Reality Exergaming on Mood and Executive Function: Exploratory Crossover Trial.

BackgroundVirtual reality (VR) exergaming is a new intervention strategy to help humans engage in physical activity to enhance mood. VR exergaming may improve both mood and executive function by acting on the prefrontal cortex, expanding the potential benefits. However, the impact of VR exergaming on executive function has not been fully investigated, and associated intervention strategies have not yet been established.ObjectiveThis study aims to investigate the effects of 10 minutes of VR exergaming on mood and executive function.MethodsA total of 12 participants played the exergame “FitXR” under 3 conditions: (1) a VR exergame condition (ie, exercise with a head-mounted display condition [VR-EX]) in which they played using a head-mounted display, (2) playing the exergame in front of a flat display (2D-EX), and (3) a resting condition in which they sat in a chair. The color-word Stroop task (CWST), which assesses executive function; the short form of the Profile of Mood States second edition (POMS2); and the short form of the Two-Dimensional Mood Scale (TDMS), which assess mood, were administered before and after the exercise or rest conditions.ResultsThe VR-EX condition increased the POMS2 vigor activity score (rest and VR-EX: t11=3.69, P=.003) as well as the TDMS arousal (rest vs 2D-EX: t11=5.34, P<.001; rest vs VR-EX: t11=5.99, P<.001; 2D-EX vs VR-EX: t11=3.02, P=.01) and vitality scores (rest vs 2D-EX: t11=3.74, P=.007; rest vs VR-EX: t11=4.84, P=.002; 2D-EX vs VR-EX: t11=3.53, P=.006), suggesting that VR exergaming enhanced mood. Conversely, there was no effect on CWST performance in either the 2D-EX or VR-EX conditions. Interestingly, the VR-EX condition showed a significant positive correlation between changes in CWST arousal and reaction time (r=0.58, P=.046). This suggests that the effect of exergaming on improving executive function may disappear under an excessively increased arousal level in VR exergaming.ConclusionsOur findings showed that 10 minutes of VR exergaming enhanced mood but did not affect executive function. This suggests that some VR content may increase cognitive demands, leading to psychological fatigue and cognitive decline as an individual approaches the limits of available attentional capacity. Future research must examine the combination of exercise and VR that enhances both brain function and mood.

Comparing the usability of a virtual reality manual wheelchair simulator in two display conditions.

Virtual reality (VR) simulators can help train manual wheelchair skills. Transfer of skills from the virtual to the real world may depend on the sense of presence, or of being “in” the virtual environment.ObjectivesTo compare 1) the usability (in terms of performance, overall experience, and satisfaction), as well as 2) the sense of presence, in a wheelchair simulator with two display conditions: a head-mounted display (HMD) or a computer monitor.MethodsSixteen healthy adults practiced in the wheelchair simulator, first with a computer monitor display and then with an HMD. Task performance, cybersickness, presence, and overall experience in VR were assessed.ResultsFour of the participants were unable to complete all tasks in the HMD condition. When comparing the two display conditions, performance was the same, except for one task (bathroom) which took longer with the computer monitor. The HMD condition was rated as significantly higher in terms of sense of presence and VR experience but provoked more intense symptoms of cybersickness.DiscussionUse of an HMD increased symptoms of cybersickness, with small gains in wheelchair performance. Thus, the use of an HMD may be warranted for the training of wheelchair skills, if tolerated by participants.

Exposure to virtual nature: the impact of different immersion levels on skin conductance level, heart rate, and perceived relaxation

It is generally accepted that natural environments reduce stress and improve mood. Since access to natural environments is sometimes limited, virtual natural environments, especially monoscopic 360° nature videos, offer a viable alternative. However, it remains unclear whether presenting monoscopic 360° nature videos via a head-mounted display (HMD) or a PC monitor results in larger relaxation effects. Therefore, this study examined whether a monoscopic 360° beach video presented with an HMD is significantly more relaxing than the same video presented via a PC screen, or no video at all (control condition), in altering skin conductance level (SCL), heart rate (HR), and perceived relaxation. Overall, 102 adults (40.2% females, age range 19–62 years) participated in a counterbalanced, randomized, controlled, within-subject experiment. All participants were subjected to three stressors comprising different mental arithmetic tasks, followed by three different recovery phases (HMD, PC, control). For SCL, the results showed a significantly larger decrease in the HMD and PC than in the control condition, but no significant differences between the HMD and PC condition. For HR, there were no significant differences between the recovery conditions. However, the HMD condition was rated significantly more relaxing than the other conditions, with no significant differences between the PC and control condition. Exploratory analyses showed that these results were not moderated by the participants’ age, gender, or technology anxiety. Overall, the psychophysiological results showed no significant benefit favoring the HMD over PC condition, although the self-reported relaxation ratings did. Future studies are warranted to clarify this divergence.

VR Disability Simulation Reduces Implicit Bias Towards Persons With Disabilities.

This article investigates how experiencing Virtual Reality (VR) Disability Simulation (DS) affects information recall and participants' implicit association towards people with disabilities (PwD). Implicit attitudes are our actions or judgments towards various concepts or stereotypes (e.g., race) which we may or may not be aware of. Previous research has shown that experiencing ownership over a dark-skinned body reduces implicit racial bias. We hypothesized that a DS with a tracked Head Mounted Display (HMD) and a wheelchair interface would have a significantly larger effect on participants' information recall and their implicit association towards PwD than a desktop monitor and gamepad. We conducted a 2 x 2 between-subjects experiment in which participants experienced a VR DS that teaches them facts about Multiple Sclerosis (MS) with factors of display (HMD, a desktop monitor) and interface (gamepad, wheelchair). Participants took two Implicit Association Tests before and after experiencing the DS. Our study results show that the participants in an immersive HMD condition performed better than the participants in the non-immersive Desktop condition in their information recall task. Moreover, a tracked HMD and a wheelchair interface had significantly larger effects on participants' implicit association towards PwD than a desktop monitor and a gamepad.

Kinematics of direct reaching in head-mounted and stereoscopic widescreen virtual environments

This research investigated the effects of virtual displays on kinematic parameters during direct pointing at a virtual target. Two virtual displays, three egocentric distances, and three indices of difficulty (IDs) were the independent variables considered in the study. Twelve participants (M = 29.8 ± 3.45 years of age) with normal visual acuity performed a pointing movement in the two VR displays, a stereoscopic widescreen display (SWD) and a head-mounted display (HMD). The movement data were compiled using a motion system. The outcomes revealed that peak velocity and reaction time differed significantly between the SWD and HMD conditions; peak velocity was higher and reaction time was shorter with the SWD than with the HMD. Nonetheless, the effective movement time and confirmation time were not significantly different between the two VR displays. In addition, the distance judgment accuracies of the HMD and SWD were 96% and 86%, respectively; distance was underestimated in the HMD and overestimated in the SWD. Moreover, both peak velocity and reaction time were significantly lower at high ID than at low and medium IDs. The results suggested that using an SWD could be more effective and efficient than an HMD for restoring motor function in upper and lower limbs. On the other hand, an HMD might be appropriate for applications which require exocentric distance judgment precision, such as architecture or medical visualization. Moreover, such findings provide valuable information for developers and designers of human interfaces and applications in virtual reality.

Analysis of Street-Crossing Behavior: Comparing a CAVE Simulator and a Head-Mounted Display among Younger and Older Adults

Interactive pedestrian simulators have become a valuable research tool for investigating street-crossing behavior and developing solutions for improving pedestrian safety. There are two main kinds of pedestrian simulators: one uses a technology based on rear-projection screens (Cave Automatic Virtual Environment, or CAVE), the other a head-mounted display (HMD). These devices are used indiscriminately, regardless of the research objective, and it is not yet known whether they are equally effective for studying street crossing. The present study was aimed at comparing the street crossing behavior and subjective evaluations of younger and older adult pedestrians when they are using a CAVE-like or HMD-based (HTC Vive Pro) pedestrian simulator. Thirty younger adults and 25 older adults performed 36 street-crossing trials (combining different speeds, two-way traffic conditions, and gap sizes) on each of the two types of simulators. The results indicated that participants in the HMD condition crossed the street significantly more often (58.6 %) than in the CAVE condition (42.44%) and had shorter safety margins. The most striking difference pertained to crossing initiation, which occurred considerably earlier (1.78 s) in the HMD condition than in the CAVE condition. Synchronization of crossing initiation with oncoming traffic was not as good in the CAVE condition because visual information in front of the pedestrian was missing due to the absence of ground projection. In both simulators, older adults caused more collisions than did younger ones, had shorter safety margins, and a slower crossing speed. Hence, the HMD reproduced classical age-related differences in most street-crossing behaviors already found on the CAVE. Usually observed speed effects were also found for both simulators. Neither cybersickness nor any adverse effects on stereoacuity or postural balance were found for either simulator. The HMD produced a higher level of presence and preference than the CAVE did. These findings provide evidence that HMDs have a clear potential for studying pedestrian behaviour.

Control of vertical posture while elevating one foot to avoid a real or virtual obstacle.

The purpose of this study is to investigate the control of vertical posture during obstacle avoidance in a real versus a virtual reality (VR) environment. Ten healthy participants stood upright and lifted one leg to avoid colliding with a real obstacle sliding on the floor toward a participant and with its virtual image. Virtual obstacles were delivered by a head mounted display (HMD) or a 3D projector. The acceleration of the foot, center of pressure, and electrical activity of the leg and trunk muscles were measured and analyzed during the time intervals typical for early postural adjustments (EPAs), anticipatory postural adjustments (APAs), and compensatory postural adjustments (CPAs). The results showed that the peak acceleration of foot elevation in the HMD condition decreased significantly when compared with that of the real and 3D projector conditions. Reduced activity of the leg and trunk muscles was seen when dealing with virtual obstacles (HMD and 3D projector) as compared with that seen when dealing with real obstacles. These effects were more pronounced during APAs and CPAs. The onsets of muscle activities in the supporting limb were seen during EPAs and APAs. The observed modulation of muscle activity and altered patterns of movement seen while avoiding a virtual obstacle should be considered when designing virtual rehabilitation protocols.

Effects of Head-Mounted Display (HMD) Position on Procedure Following Tasks and Usability

Background Head-mounted displays (HMDs) have found value in industrial applications as aids in performing long and/or complicated procedural tasks. Currently, there are gaps in understanding the impact of various design characteristics on the performance of tasks aided by HMDs. This study investigated how different positioning of head mounted displays affected the performance of workers during procedure following tasks. Methods Eight car maintenance tasks were performed by 20 participants with task guidance presented at four display conditions: above-eye, eye-centered, below-eye and via traditional paper manual. Task times, errors were measured and user experience measurements were collected. Results The results showed that none of the display conditions had significant effects on completion times. However, below-eye display outperformed the above-eye display condition for tasks requiring participants to perform assessments. User experience ratings showed that the eye-central condition was the most preferred display position among the three HMD conditions. Conclusions A non-transparent, monocular HMD that partially blocks a user’s FoV was not observed to significantly decrease overall task performance time. In support of previous findings, an HMD positioned below the eye outperformed the above-eye position for assess actions in this study. User overreliance on the instructions provided via HMD was also observed in this study. In a slightly different finding from previous studies, users indicated that the eye-central HMD position provided the best overall experience and was the most preferred by participants in this study.

A comparative evaluation of viewing metaphors on psychophysical skills education in an interactive virtual environment

In an empirical evaluation, we examined the effect of viewing condition on psychophysical skills education in an interactive 3D simulation to train users in electrical circuitry. We compared an immersive head-mounted display (HMD)-based viewing metaphor versus a limited, desktop-based virtual reality (DVR) viewing metaphor with interaction using a spatial user interface. Psychophysical skills education involves the association of cognitive functions with motor functions to make the task autonomous with repeated practice. In electrical circuitry, this is demonstrated by the fine movements involved in handling and manipulating components on the electrical circuit, particularly while measuring electrical parameters. We created an interactive circuitry simulation (IBAS) where participants could learn about electrical measurement instruments such as the ammeter, voltmeter and multimeter, in a simulated breadboard VR system. Twenty-four participants utilized the simulation (12 in each condition), and the quantitative and qualitative aspects of psychophysical skills education with respect to the viewing metaphor were examined. Each viewing condition in IBAS was head-tracked and non-stereoscopic. Perspective correction was coupled with head-tracking in the DVR condition. The key quantitative measures were cognitive questionnaires addressing different levels of Bloom's cognitive taxonomy and a real-world psychophysical task addressing various levels of Dave's psychomotor taxonomy. The qualitative measures were the Witmer---Singer sense of presence questionnaire and self-report. Results suggest that there was a significant increase in cognition post-experiment in both DVR and HMD viewing conditions in levels of knowledge, application, analysis and evaluation. Results also revealed a significant learning benefit with respect to the higher level concepts pertaining to evaluation in the HMD condition as compared to DVR. Participants seem to have enjoyed a greater level of affordance in task performance and spent a larger amount of time to complete the simulated exercises as well as manually maneuvered to further distances in the HMD viewing condition as compared to DVR viewing.

Sense of presence and anxiety during virtual social interactions between a human and virtual humans.

Virtual reality exposure therapy (VRET) has been shown to be effective in treatment of anxiety disorders. Yet, there is lack of research on the extent to which interaction between the individual and virtual humans can be successfully implanted to increase levels of anxiety for therapeutic purposes. This proof-of-concept pilot study aimed at examining levels of the sense of presence and anxiety during exposure to virtual environments involving social interaction with virtual humans and using different virtual reality displays. A non-clinical sample of 38 participants was randomly assigned to either a head-mounted display (HMD) with motion tracker and sterescopic view condition or a one-screen projection-based virtual reality display condition. Participants in both conditions engaged in free speech dialogues with virtual humans controlled by research assistants. It was hypothesized that exposure to virtual social interactions will elicit moderate levels of sense of presence and anxiety in both groups. Further it was expected that participants in the HMD condition will report higher scores of sense of presence and anxiety than participants in the one-screen projection-based display condition. Results revealed that in both conditions virtual social interactions were associated with moderate levels of sense of presence and anxiety. Additionally, participants in the HMD condition reported significantly higher levels of presence than those in the one-screen projection-based display condition (p = .001). However, contrary to the expectations neither the average level of anxiety nor the highest level of anxiety during exposure to social virtual environments differed between the groups (p = .97 and p = .75, respectively). The findings suggest that virtual social interactions can be successfully applied in VRET to enhance sense of presence and anxiety. Furthermore, our results indicate that one-screen projection-based displays can successfully activate levels of anxiety in social virtual environments. The outcome can prove helpful in using low-cost projection-based virtual reality environments for treating individuals with social phobia.

Using virtual reality driving simulators in persons with spinal cord injury: three screen display versus head mounted display

Purpose: Virtual reality (VR) is a relatively new technology that is currently utilized in a wide variety of settings to test and train individuals in specialized skills. This study examines methods for improving driver retraining protocols for persons with spinal cord injury (SCI). Method: We compared a VR driving simulator, under two different display conditions, a head mounted display (HMD) and a three screen display (TSD) to identify the best method for retraining driving skills following SCI. Results: Although there was minimal evidence for driving performance difficulties in the HMD condition relative to the TSD condition (e.g. greater number of times for being off course and longer stopping latencies for the HMD condition), rates of simulator sickness did not differ between display conditions. Conclusions: Taken together, findings suggest that both the HMD and the TSD are reasonable simulator options for driver retraining in SCI.Implications for RehabilitationVirtual reality (VR) may be a useful tool for improving driver retraining for persons with spinal cord injury (SCI).Both head mounted display (HMD) and three screen display (TSD) virtual reality systems are reasonable simulator options for driver retraining in SCI.

Do the Physical Characteristics of a Virtual Reality Device Contraindicate Its Use for Balance Assessment?

Virtual reality environments may allow researchers to investigate functional balance performance without risks associated with testing in the real world. To investigate the effects of the mass of a head-mounted display (HMD) on balance performance. Counterbalanced pretest-posttest. Virtual reality laboratory. 20 healthy college students. Balance Error Scoring System (BESS) with a tracker-only headband and again with tracker plus HMD was performed. BESS error scores, elliptical sway area, and center of pressure travel distance were recorded. No effect of the HMD mass on balance performance was observed. A significant stance by surface interaction was present but was negated when the HMD conditions were included in the model. The mass of a HMD has not been proven to adversely affect balance performance. These data suggest the HMD mass is not a contraindication to the use of immersive virtual environments in future concussion research involving balance.