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.

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

The use of head-mounted displays (HMD) for virtual reality (VR) application-based purposes including therapy, rehabilitation, and training is increasing. Despite advancements in VR technologies, many users still experience sickness symptoms. VR sickness may be influenced by technological differences within HMDs such as resolution and refresh rate, however, VR content also plays a significant role. The primary objective of this systematic review and meta-analysis was to examine the literature on HMDs that report Simulator Sickness Questionnaire (SSQ) scores to determine the impact of content. User factors associated with VR sickness were also examined. A systematic search was conducted according to PRISMA guidelines. Fifty-five articles met inclusion criteria, representing 3,016 participants (mean age range 19.5-80; 41% female). Findings show gaming content recorded the highest total SSQ mean 34.26 (95%CI 29.57-38.95). VR sickness profiles were also influenced by visual stimulation, locomotion and exposure times. Older samples (mean age ≥35 years) scored significantly lower total SSQ means than younger samples, however, these findings are based on a small evidence base as a limited number of studies included older users. No sex differences were found. Across all types of content, the pooled total SSQ mean was relatively high 28.00 (95%CI 24.66-31.35) compared with recommended SSQ cut-off scores. These findings are of relevance for informing future research and the application of VR in different contexts.

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Factors Associated With Virtual Reality Sickness in Head-Mounted Displays: A Systematic Review and Meta-Analysis

Motion sickness is a complex syndrome that includes many features besides nausea and vomiting. This review describes some of these factors and points out that under normal circumstances, many cases of motion sickness go unrecognized. Motion sickness can occur during exposure to physical motion, visual motion, and virtual motion, and only those without a functioning vestibular system are fully immune. The range of vulnerability in the normal population varies about 10,000 to 1. Sleep deprivation can also enhance susceptibility. Systematic studies conducted in parabolic flight have identified velocity storage of semicircular canal signals—velocity integration—as being a key factor in both space motion sickness and terrestrial motion sickness. Adaptation procedures that have been developed to increase resistance to motion sickness reduce this time constant. A fully adequate theory of motion sickness is not presently available. Limitations of two popular theories, the evolutionary and the ecological, are described. A sensory conflict theory can explain many but not all aspects of motion sickness elicitation. However, extending the theory to include conflicts related to visceral afferent feedback elicited by voluntary and passive body motion greatly expands its explanatory range. Future goals should include determining why some conflicts are provocative and others are not but instead lead to perceptual reinterpretations of ongoing body motion. The contribution of visceral afferents in relation to vestibular and cerebellar signals in evoking sickness also deserves further exploration. Substantial progress is being made in identifying the physiological mechanisms underlying the evocation of nausea, vomiting, and anxiety, and a comprehensive understanding of motion sickness may soon be attainable. Adequate anti-motion sickness drugs without adverse side effects are not yet available.

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Motion sickness: more than nausea and vomiting

Immersive virtual reality has become increasingly popular to improve the assessment and treatment of health problems. This rising popularity is likely to be facilitated by the availability of affordable headsets that deliver high quality immersive experiences. As many health problems are more prevalent in older adults, who are less technology experienced, it is important to know whether they are willing to use immersive virtual reality. In this study, we assessed the initial attitude towards head-mounted immersive virtual reality in 76 older adults who had never used virtual reality before. Furthermore, we assessed changes in attitude as well as self-reported cybersickness after a first exposure to immersive virtual reality relative to exposure to time-lapse videos. Attitudes towards immersive virtual reality changed from neutral to positive after a first exposure to immersive virtual reality, but not after exposure to time-lapse videos. Moreover, self-reported cybersickness was minimal and had no association with exposure to immersive virtual reality. These results imply that the contribution of VR applications to health in older adults will neither be hindered by negative attitudes nor by cybersickness.

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Acceptance of immersive head-mounted virtual reality in older adults.

Motion sickness (MS) is a common physiological response to real or virtual motion. Numerous studies have investigated the neurobiological mechanism and the control measures of MS. This review summarizes the current knowledge about pathogenesis and pathophysiology, prediction, evaluation, and countermeasures of MS. The sensory conflict hypothesis is the most widely accepted theory for MS. Both the hippocampus and vestibular cortex might play a role in forming internal model. The pathophysiology focuses on the visceral afference, thermoregulation and MS-related neuroendocrine. Single-nucleotide polymorphisms (SNPs) in some genes and epigenetic modulation might contribute to MS susceptibility and habituation. Questionnaires, heart rate variability (HRV) and electrogastrogram (EGG) are useful for diagnosing and evaluating MS. We also list MS medications to guide clinical practice. Repeated real motion exposure and combined visual-vestibular interaction training accelerate the progress of habituation. Behavioral and dietary countermeasures, as well as physiotherapy, are also effective in alleviating MS symptoms.

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Motion Sickness: Current Knowledge and Recent Advance.

Several studies have suggested that anxiety may play a role in motion sickness susceptibility (MSS) variability This study aimed to assess motion sickness susceptibility in healthy subjects and chronic vestibular patients and to investigate its relationship to gender, age and trait-anxiety Healthy subjects (n=167) and chronic dizzy patients with various vestibulopathies (n=94), aged from 20 to 92 years old, were asked to complete Motion Sickness Susceptibility questionnaire (MSSQ) and trait-anxiety questionnaire (STAI-B) When patients were divided into those who had vestibular loss (n=51) vs patients without vestibular loss (n=43), the MSSQ scores (mean ± SD) for patients with vestibular loss (188 ± 309) were lower than healthy subjects (364 ± 348), who were lower than vestibular patients without vestibular loss (590 ± 397) These significant differences could not be explained by gender, age, trait-anxiety, or interaction Women had higher MSS than men, and MSS declined with age for healthy subjects and vestibular patients The overall relationship between anxiety and MSS scores was weak and only reached significance in healthy subjects These results support the conclusion that the vestibular system is heavily involved in MSS and that trait-anxiety may play a role in MSS but only in healthy subjects

Fabio Paolino

Papers

Motion sickness susceptibility in healthy subjects and vestibular patients: Effects of gender, age and trait-anxiety