EVALUATION OF VISUALLY INDUCED MOTION SICKNESS CAUSED BY VIEWING OF 3D STEREOSCOPY USING ELECTROENCEPHALOGRAPHY TECHNIQUE

The 3D movies are attracting the viewers as they see objects flying out of the screen. However, many viewers reportof problems that they face after watching 3D movies. Visual fatigue, eye strain, headaches, dizziness, blurred vision or in other words, Visually Induced Motion Sickness (VIMS) are reported by viewers of 3D movies. In this thesis, we aim to compare a 3D passive technology with a conventional 2D technology to find whether 3D is causing trouble in the viewers or not

Quality of Experience Comparison of Stereoscopic 3D Videos in Different Projection Devices: Flat Screen, Panoramic Screen and Virtual Reality Headset

The use of Stereoscopic 3D (S3D) videos has been popular in commercial markets with ongoing developments in the field of visual entertainment in recent years. A wide variety of projection methods of 3D video content is currently available, such as projection to a panoramic screen and projection of omnidirectional video content from head mounted displays using Virtual Reality (VR) technology. This article investigates the Quality of Experience (QoE) and associated Visually Induced Motion Sickness (VIMS) caused by the viewing of S3D videos. The investigations used three different projection screens: a 3D flat screen, a 3D panoramic screen in a hemispherical shaped room and a VR headset. Several assessment methods including a Simulator Sickness Questionnaire (SSQ), ElectroEncephaloGraphy (EEG), and measurement tools for eye blink rate detection were applied to measure the QoE experienced by viewers. The SSQ scores were also compared with the behavioral data such as attention and meditation levels and enjoyment ratings acquired from different video content and projection screens. The results indicate that the projection screen is a key factor affecting the level of visual fatigue, VIMS and QoE assessments, which are discussed in-depth in the article

Visual discomfort whilst viewing 3D stereoscopic stimuli

3D stereoscopic technology intensifies and heightens the viewer s experience by adding an extra dimension to the viewing of visual content. However, with expansion of this technology to the commercial market concerns have been expressed about the potential negative effects on the visual system, producing viewer discomfort. The visual stimulus provided by a 3D stereoscopic display differs from that of the real world, and so it is important to understand whether these differences may pose a health hazard. The aim of this thesis is to investigate the effect of 3D stereoscopic stimulation on visual discomfort. To that end, four experimental studies were conducted. In the first study two hypotheses were tested. The first hypothesis was that the viewing of 3D stereoscopic stimuli, which are located geometrically beyond the screen on which the images are displayed, would induce adaptation changes in the resting position of the eyes (exophoric heterophoria changes). The second hypothesis was that participants whose heterophoria changed as a consequence of adaptation during the viewing of the stereoscopic stimuli would experience less visual discomfort than those people whose heterophoria did not adapt. In the experiment an increase of visual discomfort change in the 3D condition in comparison with the 2D condition was found. Also, there were statistically significant changes in heterophoria under 3D conditions as compared with 2D conditions. However, there was appreciable variability in the magnitude of this adaptation among individuals, and no correlation between the amount of heterophoria change and visual discomfort change was observed. In the second experiment the two hypotheses tested were based on the vergence-accommodation mismatch theory, and the visual-vestibular mismatch theory. The vergence-accommodation mismatch theory predicts that a greater mismatch between the stimuli to accommodation and to vergence would produce greater symptoms in visual discomfort when viewing in 3D conditions than when viewing in 2D conditions. An increase of visual discomfort change in the 3D condition in comparison with the 2D condition was indeed found; however the magnitude of visual discomfort reported did not correlate with the mismatch present during the watching of 3D stereoscopic stimuli. The visual-vestibular mismatch theory predicts that viewing a stimulus stereoscopically will produce a greater sense of vection than viewing it in 2D. This will increase the conflict between the signals from the visual and vestibular systems, producing greater VIMS (Visually- Induced Motion Sickness) symptoms. Participants did indeed report an increase in motion sickness symptoms in the 3D condition. Furthermore, participants with closer seating positions reported more VIMS than participants sitting farther away whilst viewing 3D stimuli. This suggests that the amount of visual field stimulated during 3D presentation affects VIMS, and is an important factor in terms of viewing comfort. In the study more younger viewers (21 to 39 years old) than older viewers (40 years old and older) reported a greater change in visual discomfort during the 3D condition than the 2D condition. This suggests that the visual system s response to a stimulus, rather than the stimulus itself, is a reason for discomfort. No influence of gender on viewing comfort was found. In the next experiment participants fusion capability, as measured by their fusional reserves, was examined to determine whether this component has an impact on reported discomfort during the watching of movies in the 3D condition versus the 2D condition. It was hypothesised that participants with limited fusional range would experience more visual discomfort than participants with a wide fusion range. The hypothesis was confirmed but only in the case of convergent and not divergent eye movement. This observation illustrates that participants capability to convergence has a significant impact on visual comfort. The aim of the last experiment was to examine responses of the accommodation system to changes in 3D stimulus position and to determine whether discrepancies in these responses (i.e. accommodation overshoot, accommodation undershoot) could account for visual discomfort experienced during 3D stereoscopic viewing. It was found that accommodation discrepancy was larger for perceived forwards movement than for perceived backwards movement. The discrepancy was slightly higher in the group susceptible to visual discomfort than in the group not susceptible to visual discomfort, but this difference was not statistically significant. When considering the research findings as a whole it was apparent that not all participants experienced more discomfort whilst watching 3D stereoscopic stimuli than whilst watching 2D stimuli. More visual discomfort in the 3D condition than in the 2D condition was reported by 35% of the participants, whilst 24% of the participants reported more headaches and 17% of the participants reported more VIMS. The research indicates that multiple causative factors have an impact on reported symptoms. The analysis of the data suggests that discomfort experienced by people during 3D stereoscopic stimulation may reveal binocular vision problems. This observation suggests that 3D technology could be used as a screening method to diagnose un-treated binocular vision disorder. Additionally, this work shows that 3D stereoscopic technology can be easily adopted to binocular vision measurement. The conclusion of this thesis is that many people do not suffer adverse symptoms when viewing 3D stereoscopic displays, but that if adverse symptoms are present they can be caused either by the conflict in the stimulus, or by the heightened experience of self-motion which leads to Visually-Induced Motion Sickness (VIMS)

VR Sickness Prediction for Navigation in Immersive Virtual Environments using a Deep Long Short Term Memory Model

International audienceThis paper proposes a new objective metric of visually induced motion sickness (VIMS) in the context of navigation in virtual environments (VEs). Similar to motion sickness in physical environments, VIMS can induce many physiological symptoms such as general discomfort, nausea, disorientation, vomiting, dizziness and fatigue. To improve user satisfaction with VR applications, it is of great significance to develop objective metrics for VIMS that can analyze and estimate the level of VR sickness when a user is exposed to VEs. One of the well-known objective metrics is the postural instability. In this paper, we trained a LSTM model for each participant using a normal-state postural signal captured before the exposure, and if the postural sway signal from post-exposure was sufficiently different from the pre-exposure signal, the model would fail at encoding and decoding the signal properly; the jump in the reconstruction error was called loss and was proposed as the proposed objective measure of simulator sickness. The effectiveness of the proposed metric was analyzed and compared with subjective assessment methods based on the simulator sickness questionnaire (SSQ) in a VR environment, achieving a Pearson correlation coefficient of .89. Finally, we showed that the proposed method had the potential to be deployed within a closed-loop system and get real-time performance to predict VR sickness, opening new insights to develop user-centered and customized VR applications based on physiological feedback

Presence and Cybersickness in Virtual Reality Are Negatively Related: A Review

In order to take advantage of the potential offered by the medium of virtual reality (VR), it will be essential to develop an understanding of how to maximize the desirable experience of “presence” in a virtual space (“being there”), and how to minimize the undesirable feeling of “cybersickness” (a constellation of discomfort symptoms experienced in VR). Although there have been frequent reports of a possible link between the observer’s sense of presence and the experience of bodily discomfort in VR, the amount of literature that discusses the nature of the relationship is limited. Recent research has underlined the possibility that these variables have shared causes, and that both factors may be manipulated with a single approach. This review paper summarizes the concepts of presence and cybersickness and highlights the strengths and gaps in our understanding about their relationship. We review studies that have measured the association between presence and cybersickness, and conclude that the balance of evidence favors a negative relationship between the two factors which is driven principally by sensory integration processes. We also discuss how system immersiveness might play a role in modulating both presence and cybersickness. However, we identify a serious absence of high-powered studies that aim to reveal the nature of this relationship. Based on this evidence we propose recommendations for future studies investigating presence, cybersickness, and other related factors

A head-mounted display as a personal viewing device : Dimensions of subjective experiences

The use of head-mounted displays (HMDs) can produce both positive and negative experiences. In an effort increase positive experiences and avoid negative ones, researchers have identified a number of variables that may cause sickness and eyestrain, although the exact nature of the relationship to HMDs may vary, depending on the tasks and the environments. Other non-sickness-related aspects of HMDs, such as users opinions and future decisions associated with task enjoyment and interest, have attracted little attention in the research community. In this thesis, user experiences associated with the use of monocular and bi-ocular HMDs were studied. These include eyestrain and sickness caused by current HMDs, the advantages and disadvantages of adjustable HMDs, HMDs as accessories for small multimedia devices, and the impact of individual characteristics and evaluated experiences on reported outcomes and opinions. The results indicate that today s commercial HMDs do not induce serious sickness or eyestrain. Reported adverse symptoms have some influence on HMD-related opinions, but the nature of the impact depends on the tasks and the devices used. As an accessory to handheld devices and as a personal viewing device, HMDs may increase use duration and enable users to perform tasks not suitable for small screens. Well-designed and functional, adjustable HMDs, especially monocular HMDs, increase viewing comfort and usability, which in turn may have a positive effect on product-related satisfaction. The role of individual characteristics in understanding HMD-related experiences has not changed significantly. Explaining other HMD-related experiences, especially forward-looking interests, also requires understanding more stable individual traits and motivations.Päässä pidettävän näytön käyttö voi olla mukava kokemus ilman silmärasituksen tai pahoinvoinnin oireita. Joskus siihen voi liittyä myös erilaisia negatiivisia tuntemuksia. Vuosien varrella on tunnistettu monia systeemiin, käyttäjään ja tehtävään liittyviä taustamuuttujia, joilla on vaikutusta negatiivisten tuntemusten ja kokemusten syntyyn. Muita, päässä pidettävän näytön käyttöön liittyviä kokemuksia ja käyttäjien mielipiteitä on tutkittu vain vähän tai ei ollenkaan. Tässä väitöskirjassa tutkittiin markkinoilla olevien erilaisten päässä pidettävien näyttöjen käyttökokemuksia. Yksityiskohtaisemmin tarkasteltiin päässä pidettävien näyttöjen käyttöön liittyvä silmärasitusta ja pahoinvointia sekä näytön säätömahdollisuuden hyötyjä ja haittoja käyttäjän näkökulmasta. Lisäksi tutkittiin laitteen käyttöä lisälaitteena muille pienille multimedialaitteille sekä sitä, miten erilaiset taustamuuttujat ja laitteen käyttöön liittyvät kokemukset auttavat meitä ymmärtämään laitteen tulevaan käyttöön liittyviä mielipiteitä. Tässä väitöskirjassa esitettyjen tutkimustulosten mukaan päässä pidettävät näytöt voivat aiheuttaa lievää silmärasitusta ja pahoinvointia, mutta erot muihin näyttöihin ovat selvästi pienentyneet. Päässä pidettävän näytön säätömahdollisuus parantaa katselukokemusta etenkin monokulaarisen päässä pidettävän näytön tapauksessa, mutta näyttöjen säädettävyys voi hyödyttää myös bi-okulaaristen näyttöjen käyttäjiä. Päässä pidettävän näytön käyttö lisälaitteena pienille multimedialaitteille pidentää sovelluksen käyttöaikaa ja mahdollistaa sellaisten tehtävien suorituksen, jotka olisivat erittäin vaativia pienellä näytöllä. Aikaisemmin julkaistujen tulosten mukaan monet käyttäjän yksilölliset ominaisuudet auttavat ymmärtämään koettua silmärasitusta ja pahoinvointia. Myös väitöskirjassa esitetyt tulokset tukevat tätä näkemystä. Johtopäätöksenä voidaankin esittää, että jos tavoitteena on ymmärtää laitteen tulevaan käyttöön liittyviä mielipiteitä, niin välittömien käyttökokemusten lisäksi pitäisi tarkastella myös käyttäjän persoonallisuuspiirteiden ja motivaatioiden vaikutusta

Leveraging eXtented Reality & Human-Computer Interaction for User Experi- ence in 360◦ Video

EXtended Reality systems have resurged as a medium for work and entertainment. While 360o video has been characterized as less immersive than computer-generated VR, its realism, ease of use and affordability mean it is in widespread commercial use. Based on the prevalence and potential of the 360o video format, this research is focused on improving and augmenting the user experience of watching 360o video. By leveraging knowledge from Extented Reality (XR) systems and Human-Computer Interaction (HCI), this research addresses two issues affecting user experience in 360o video: Attention Guidance and Visually Induced Motion Sickness (VIMS). This research work relies on the construction of multiple artifacts to answer the de- fined research questions: (1) IVRUX, a tool for analysis of immersive VR narrative expe- riences; (2) Cue Control, a tool for creation of spatial audio soundtracks for 360o video, as well as enabling the collection and analysis of captured metrics emerging from the user experience; and (3) VIMS mitigation pipeline, a linear sequence of modules (including optical flow and visual SLAM among others) that control parameters for visual modi- fications such as a restricted Field of View (FoV). These artifacts are accompanied by evaluation studies targeting the defined research questions. Through Cue Control, this research shows that non-diegetic music can be spatialized to act as orientation for users. A partial spatialization of music was deemed ineffective when used for orientation. Addi- tionally, our results also demonstrate that diegetic sounds are used for notification rather than orientation. Through VIMS mitigation pipeline, this research shows that dynamic restricted FoV is statistically significant in mitigating VIMS, while mantaining desired levels of Presence. Both Cue Control and the VIMS mitigation pipeline emerged from a Research through Design (RtD) approach, where the IVRUX artifact is the product of de- sign knowledge and gave direction to research. The research presented in this thesis is of interest to practitioners and researchers working on 360o video and helps delineate future directions in making 360o video a rich design space for interaction and narrative.Sistemas de Realidade EXtendida ressurgiram como um meio de comunicação para o tra- balho e entretenimento. Enquanto que o vídeo 360o tem sido caracterizado como sendo menos imersivo que a Realidade Virtual gerada por computador, o seu realismo, facili- dade de uso e acessibilidade significa que tem uso comercial generalizado. Baseado na prevalência e potencial do formato de vídeo 360o, esta pesquisa está focada em melhorar e aumentar a experiência de utilizador ao ver vídeos 360o. Impulsionado por conhecimento de sistemas de Realidade eXtendida (XR) e Interacção Humano-Computador (HCI), esta pesquisa aborda dois problemas que afetam a experiência de utilizador em vídeo 360o: Orientação de Atenção e Enjoo de Movimento Induzido Visualmente (VIMS). Este trabalho de pesquisa é apoiado na construção de múltiplos artefactos para res- ponder as perguntas de pesquisa definidas: (1) IVRUX, uma ferramenta para análise de experiências narrativas imersivas em VR; (2) Cue Control, uma ferramenta para a criação de bandas sonoras de áudio espacial, enquanto permite a recolha e análise de métricas capturadas emergentes da experiencia de utilizador; e (3) canal para a mitigação de VIMS, uma sequência linear de módulos (incluindo fluxo ótico e SLAM visual entre outros) que controla parâmetros para modificações visuais como o campo de visão restringido. Estes artefactos estão acompanhados por estudos de avaliação direcionados para às perguntas de pesquisa definidas. Através do Cue Control, esta pesquisa mostra que música não- diegética pode ser espacializada para servir como orientação para os utilizadores. Uma espacialização parcial da música foi considerada ineficaz quando usada para a orientação. Adicionalmente, os nossos resultados demonstram que sons diegéticos são usados para notificação em vez de orientação. Através do canal para a mitigação de VIMS, esta pesquisa mostra que o campo de visão restrito e dinâmico é estatisticamente significante ao mitigar VIMS, enquanto mantem níveis desejados de Presença. Ambos Cue Control e o canal para a mitigação de VIMS emergiram de uma abordagem de Pesquisa através do Design (RtD), onde o artefacto IVRUX é o produto de conhecimento de design e deu direcção à pesquisa. A pesquisa apresentada nesta tese é de interesse para profissionais e investigadores tra- balhando em vídeo 360o e ajuda a delinear futuras direções em tornar o vídeo 360o um espaço de design rico para a interação e narrativa

Sensory Conflict: Effects on the Perceived Onset of Motion and Cybersickness in Virtual Reality

The perception of self-motion involves the integration of multisensory information, however there are scenarios in which the sensory feedback we receive from these different sources can conflict with one another. For example, when inside the cabin of a ship at sea or playing a game in virtual reality (VR), sensory signals for self-motion from the visual and vestibular systems may not be congruent. It has been well documented that such scenarios are associated with feelings of discomfort and alterations in our perception of motion, but the mechanisms leading to these perceptual consequences remain uncertain. The goal of this dissertation is to explore the effect of sensory conflict between vestibular and visual signals on the perception of self-motion and implications for cybersickness. Chapter Two examined the effect of sensory conflict on the perceived timing of a passive whole-body rotation paired with both congruent and incongruent visual feedback using VR. It was found that the visual signal only influenced the perception of movement onset when the direction of the visual motion did not match the expected equal and opposite response relative to physical rotation. In Chapter Three, the effect of sensory conflict between visual, vestibular and body cues on the perceived timing of visual motion was explored. The results revealed that changing the orientation of the body relative to gravity to dissociate the relationship between vestibular and body cues of upright delays the perceived onset of visual yaw rotation in VR by an additional 30ms compared to an upright posture. Lastly, Chapter Four investigated the relationship between sensory conflict and sensory reweighting through measures of cybersickness and sensory perception after exposure to VR gameplay. The results indicated that the perception of subjective vertical was significantly influenced by an intense VR experience and that sensory reweighting may play a role in this effect, along with providing a potential explanation for individual differences for cybersickness severity. Altogether, this dissertation highlights some of the perceptual consequences of sensory conflict between vestibular and visual signals and provides insights for the potential mechanisms that determine the perception of self-motion and cybersickness in VR