I Am The Passenger: How Visual Motion Cues Can Influence Sickness For In-Car VR

This paper explores the use of VR Head Mounted Displays (HMDs) in-car and in-motion for the first time. Immersive HMDs are becoming everyday consumer items and, as they offer new possibilities for entertainment and productivity, people will want to use them during travel in, for example, autonomous cars. However, their use is confounded by motion sickness caused in-part by the restricted visual perception of motion conflicting with physically perceived vehicle motion (accelerations/rotations detected by the vestibular system). Whilst VR HMDs restrict visual perception of motion, they could also render it virtually, potentially alleviating sensory conflict. To study this problem, we conducted the first on-road and in motion study to systematically investigate the effects of various visual presentations of the real-world motion of a car on the sickness and immersion of VR HMD wearing passengers. We established new baselines for VR in-car motion sickness, and found that there is no one best presentation with respect to balancing sickness and immersion. Instead, user preferences suggest different solutions are required for differently susceptible users to provide usable VR in-car. This work provides formative insights for VR designers and an entry point for further research into enabling use of VR HMDs, and the rich experiences they offer, when travelling

Fidelity metrics for virtual environment simulations based on spatial memory awareness states

This paper describes a methodology based on human judgments of memory awareness states for assessing the simulation fidelity of a virtual environment (VE) in relation to its real scene counterpart. To demonstrate the distinction between task performance-based approaches and additional human evaluation of cognitive awareness states, a photorealistic VE was created. Resulting scenes displayed on a headmounted display (HMD) with or without head tracking and desktop monitor were then compared to the real-world task situation they represented, investigating spatial memory after exposure. Participants described how they completed their spatial recollections by selecting one of four choices of awareness states after retrieval in an initial test and a retention test a week after exposure to the environment. These reflected the level of visual mental imagery involved during retrieval, the familiarity of the recollection and also included guesses, even if informed. Experimental results revealed variations in the distribution of participants’ awareness states across conditions while, in certain cases, task performance failed to reveal any. Experimental conditions that incorporated head tracking were not associated with visually induced recollections. Generally, simulation of task performance does not necessarily lead to simulation of the awareness states involved when completing a memory task. The general premise of this research focuses on how tasks are achieved, rather than only on what is achieved. The extent to which judgments of human memory recall, memory awareness states, and presence in the physical and VE are similar provides a fidelity metric of the simulation in question

CHARACTERISTICS OF HEAD MOUNTED DISPLAYS AND THEIR EFFECTS ON SIMULATOR SICKNESS

Characteristics of head-mounted displays (HMDs) and their effects on simulator sickness (SS) and presence were investigated. Update delay and wide field of views (FOV) have often been thought to elicit SS. With the exception of Draper et al. (2001), previous research that has examined FOV has failed to consider image scale factor, or the ratio between physical FOV of the HMD display and the geometric field of view (GFOV) of the virtual environment (VE). The current study investigated update delay, image scale factor, and peripheral vision on SS and presence when viewing a real-world scene. Participants donned an HMD and performed active head movements to search for objects located throughout the laboratory. Seven out of the first 28 participants withdrew from the study due to extreme responses. These participants experienced faint-like symptoms, confusion, ataxia, nausea, and tunnel vision. Thereafter, the use of a hand-rail was implemented to provide participants something to grasp while performing the experimental task. The 2X2X2 ANOVA revealed a main effect of peripheral vision, F(1,72) = 6.90, p= .01, indicating peak Simulator Sickness Questionnaire (SSQ) scores were significantly higher when peripheral vision was occluded than when peripheral vision was included. No main effects or interaction effects were revealed on Presence Questionnaire (PQ version 4.0) scores. However, a significant negative correlation of peak SSQ scores and PQ scores, r(77) = -.28, p= .013 was revealed. Participants also were placed into \u27sick\u27 and \u27not-sick\u27 groups based on a median split of SSQ scores. A chi-square analysis revealed that participants who were exposed to an additional update delay of ~200 ms were significantly more likely to be in the \u27sick\u27 group than those who were exposed to no additional update delay. To reduce the occurrence of SS, a degree of peripheral vision of the external world should be included and attempts to reduce update delay should continue. Furthermore, participants should be provided with something to grasp while in an HMD VE. Future studies should seek to investigate a critical amount of peripheral vision and update delay necessary to elicit SS

Simulator sickness when performing gaze shifts within a wide field of view optic flow environment: preliminary evidence for using virtual reality in vestibular rehabilitation

BACKGROUND: Wide field of view virtual environments offer some unique features that may be beneficial for use in vestibular rehabilitation. For one, optic flow information extracted from the periphery may be critical for recalibrating the sensory processes used by people with vestibular disorders. However, wide FOV devices also have been found to result in greater simulator sickness. Before a wide FOV device can be used in a clinical setting, its safety must be demonstrated. METHODS: Symptoms of simulator sickness were recorded by 9 healthy adult subjects after they performed gaze shifting tasks to locate targets superimposed on an optic flow background. Subjects performed 8 trials of gaze shifting on each of the six separate visits. RESULTS: The incidence of symptoms of simulator sickness while subjects performed gaze shifts in an optic flow environment was lower than the average reported incidence for flight simulators. The incidence was greater during the first visit compared with subsequent visits. Furthermore, the incidence showed an increasing trend over the 8 trials. CONCLUSION: The performance of head unrestrained gaze shifts in a wide FOV optic flow environment is tolerated well by healthy subjects. This finding provides rationale for testing these environments in people with vestibular disorders, and supports the concept of using wide FOV virtual reality for vestibular rehabilitation

Latency Requirements for Head-Worn Display S/EVS Applications

NASA s Aviation Safety Program, Synthetic Vision Systems Project is conducting research in advanced flight deck concepts, such as Synthetic/Enhanced Vision Systems (S/EVS), for commercial and business aircraft. An emerging thrust in this activity is the development of spatially-integrated, large field-of-regard information display systems. Head-worn or helmet-mounted display systems are being proposed as one method in which to meet this objective. System delays or latencies inherent to spatially-integrated, head-worn displays critically influence the display utility, usability, and acceptability. Research results from three different, yet similar technical areas flight control, flight simulation, and virtual reality are collectively assembled in this paper to create a global perspective of delay or latency effects in head-worn or helmet-mounted display systems. Consistent definitions and measurement techniques are proposed herein for universal application and latency requirements for Head-Worn Display S/EVS applications are drafted. Future research areas are defined

THE ROLE OF HEAD MOVEMENTS IN SIMULATOR SICKNESS GENERATED BY A VIRTUAL ENVIRONMENT

Virtual environments (VEs) are being used in a variety of applications, including training, rehabilitation and clinical treatment. To effectively utilize VEs in these situations it is important to try to understand some of the effects of VE exposure. The purpose of this study was to investigate head and body movements in virtual and real environments during building clearing and the relationship between these movements and simulator sickness. The data for the current study were drawn from a larger team training study which investigated the use of VEs for training building clearing. The goal of the first part of this study was to compare head movements made in a real world (RW) environment to head movements made in a VE (Analysis I). The goal of second part of this study was to examine the relationship between head movements and simulator sickness in a VE (Analysis II). The first analysis used two independent samples t-tests to examine the differences between head movements made in a VE and head movements made in a RW environment. The t-tests showed that subjects in the VE moved their heads less, t(23.438)=12.690, p\u3c0.01, and less often, t(46)=8.682, p\u3c0.05, than subjects in the RW. In the second analysis, a 3 x 20 ANOVA found a significant difference between groups with low, med, and high simulator sickness scores, F(2,21)=4.221, p\u3c0.05, ήp2= 0.287, where subjects who reported being the most sick tended to restrict their head movements more than the other two groups. For VEs to progress as a useful tool, whether for training, therapy, etc., it will be necessary to identify the variable(s) that cause people to become motion sick and restrict their head movement during VE exposure. Future studies should seek to investigate more continuous measures of sickness, perhaps psychophysiological measures, and possible effects of a negative transfer of training due to the restriction of head movements in VEs

Augmenting low-fidelity flight simulation training devices via amplified head rotations

Due to economic and operational constraints, there is an increasing demand from aviation operators and training manufacturers to extract maximum training usage from the lower fidelity suite of flight simulators. It is possible to augment low-fidelity flight simulators to achieve equivalent performance compared to high-fidelity setups but at reduced cost and greater mobility. In particular for visual manoeuvres, the virtual reality technique of head-tracking amplification for virtual view control enables full field-of-regard access even with limited field-of-view displays. This research quantified the effects of this technique on piloting performance, workload and simulator sickness by applying it to a fixed-base, low-fidelity, low-cost flight simulator. In two separate simulator trials, participants had to land a simulated aircraft from a visual traffic circuit pattern whilst scanning for airborne traffic. Initially, a single augmented display was compared to the common triple display setup in front of the pilot. Starting from the base leg, pilots exhibited tighter turns closer to the desired ground track and were more actively conducting visual scans using the augmented display. This was followed up by a second experiment to quantify the scalability of augmentation towards larger displays and field of views. Task complexity was increased by starting the traffic pattern from the downwind leg. Triple displays in front of the pilot yielded the best compromise delivering flight performance and traffic detection scores just below the triple projectors but without an increase in track deviations and the pilots were also less prone to simulator sickness symptoms. This research demonstrated that head augmentation yields clear benefits of quick user adaptation, low-cost, ease of systems integration, together with the capability to negate the impact of display sizes yet without incurring significant penalties in workload and incurring simulator sickness. The impact of this research is that it facilitates future flight training solutions using this augmentation technique to meet budgetary and mobility requirements. This enables deployment of simulators in large numbers to deliver expanded mission rehearsal previously unattainable within this class of low-fidelity simulators, and with no restrictions for transfer to other training media

Use of Incremental Adaptation and Habituation Regimens for Mitigating Optokinetic Side-effects

The use of incremental and repeated exposures regimens have been put forth as effective means to mitigate visually induced motion sickness based on the Dual Process Theory (DPT) (Groves & Thompson, 1970) of neural plasticity. In essence, DPT suggests that by incrementing stimulus intensity the depression opponent process should be allowed to exert greater control over the net outcome than the sensitization opponent process, thereby minimizing side-effects. This conceptual model was tested by empirically validating the effectiveness of adaptation, incremental adaptation, habituation, and incremental habituation regimens to mitigate side-effects arising from exposure to an optokinetic drum. Forty college students from the University of Central Florida participated in the experimentation and were randomly assigned to a regimen. Efforts were taken to balance distribution of participants in the treatments for gender and motion sickness susceptibility. Results indicated that overall, the application of an incremental regimen is effective in reducing side-effects (e.g. malaise, dropout rates, postural instabilities, etc.) when compared to a non-incremented regimen, whether it be a one-time or repeated exposure. Furthermore, the application of the Motion History Questionnaire (MHQ) (Graybiel & Kennedy, 1965) for identifying high and low motion sickness susceptible individuals proved effective. Finally, gender differences in motion sickness were not found in this experiment as a result of balancing susceptibility with the gender subject variable. Findings from this study can be used to aid effective design of virtual environment (VE) usage regimens in an effort to manage cybersickness. Through pre-exposure identification of susceptible individuals via the MHQ, exposure protocols can be devised that may extend limits on exposure durations, mitigate side-effects, reduce dropout rates, and possibly increase training effectiveness. This document contains a fledgling set of guidelines form VE usage that append those under development by Stanney, Kennedy, & Kingdon (In press) and other previously established guidelines form simulator use (Kennedy et al., 1987). It is believed that through proper allocation of effective VE usage regimens cybersickness can be managed, if susceptible individuals are identified prior to exposure