Visually Induced Motion Sickness Research Articles

Vection and visually induced motion sickness: how are they related?

The occurrence of visually induced motion sickness has been frequently linked to the sensation of illusory self-motion (vection), however, the precise nature of this relationship is still not fully understood. To date, it is still a matter of debate as to whether vection is a necessary prerequisite for visually induced motion sickness (VIMS). That is, can there be VIMS without any sensation of self-motion? In this paper, we will describe the possible nature of this relationship, review the literature that addresses this relationship (including theoretical accounts of vection and VIMS), and offer suggestions with respect to operationally defining and reporting these phenomena in future.

Motion in images is essential to cause motion sickness symptoms, but not to increase postural sway

ObjectiveIt is generally assumed that motion in motion images is responsible for increased postural sway as well as for visually induced motion sickness (VIMS). However, this has not yet been tested. To that end, we studied postural sway and VIMS induced by motion and still images. Method15 Participants were exposed to motion- and still images in separate sessions. Motion images consisted of video clips taken from a first person shooter game. Still images consisted of stills taken every 10s from these same clips. Before, during, and after exposure, VIMS was rated and postural sway was measured. Sway path length, standard deviation and short- and long-term scaling components of the centre of pressure were calculated as measures of postural sway. ResultsVIMS scores obtained during and after exposure to motion images were significantly higher compared to scores obtained before, and directly after exposure to still images. The sway path length, standard deviation in anteroposterior direction and short-term scaling components in mediolateral and anteroposterior direction increased significantly during exposure to motion and still images. ConclusionIn this experiment motion- and still images caused different levels of VIMS, but comparable increases in postural sway. We assume VIMS was caused by a mismatch between visual and vestibular motion cues. The increase in sway during exposure to still images can be explained by visual effects present in still images. The lack of vection in the motion images may explain why sway was not larger when viewing these motion images as compared to viewing the still images.

Visually induced motion sickness can be alleviated by pleasant odors.

Visually induced motion sickness (VIMS) is a common side effect in virtual environments and simulators. Several countermeasures against VIMS exist, but a reliable method to prevent or ease VIMS is unfortunately still missing. In the present study, we tested whether olfactory cues can alleviate VIMS. Sixty-two participants were exposed to a 15-min-long video showing a first-person-view bicycle ride that had successfully induced VIMS in previous studies. Participants were randomly assigned to one of three groups; the first group was exposed to a pleasant odor (rose) while watching the video, the second group was exposed to an unpleasant odor (leather), and the third group was not exposed to any odor. VIMS was measured using a verbal rating scale (0-20) and the Simulator Sickness Questionnaire. Results showed that only half of the participants who were exposed to the odor did notice it (n = 21), whereas the other half failed to detect the odor. However, among those participants who did notice the odor, the rose scent significantly reduced the severity of VIMS compared to the group that did not notice the odor. A moderate positive correlation between odor sensitivity and VIMS showed that participants with higher odor sensitivity also reported stronger VIMS. Our results demonstrate that olfaction can modulate VIMS and that a pleasant odor can potentially reduce VIMS. The relationship between olfactory perception, olfactory sensibility, and VIMS is discussed.

Investigation of visually induced motion sickness in dynamic 3D contents based on subjective judgment, heart rate variability, and depth gaze behavior.

Visually induced motion sickness (VIMS) is an important safety issue in stereoscopic 3D technology. Accompanying subjective judgment of VIMS with objective measurement is useful to identify not only biomedical effects of dynamic 3D contents, but also provoking scenes that induce VIMS, duration of VIMS, and user behavior during VIMS. Heart rate variability and depth gaze behavior are appropriate physiological indicators for such objective observation. However, there is no information about relationship between subjective judgment of VIMS, heart rate variability, and depth gaze behavior. In this paper, we present a novel investigation of VIMS based on simulator sickness questionnaire (SSQ), electrocardiography (ECG), and 3D gaze tracking. Statistical analysis on SSQ data shows that nausea and disorientation symptoms increase as amount of dynamic motions increases (nausea: p<;0.005; disorientation: p<;0.05). To reduce VIMS, SSQ and ECG data suggest that user should perform voluntary gaze fixation at one point when experiencing vertical motion (up or down) and horizontal motion (turn left and right) in dynamic 3D contents. Observation of 3D gaze tracking data reveals that users who experienced VIMS tended to have unstable depth gaze than ones who did not experience VIMS.

OC-064 Psychophysiological And Cortical Responses To Visually Induced Motion Sickness

IntroductionNausea is an aversive experience, which negatively impacts on quality of life, adherence to treatment and is a cause for discontinuation of the development of novel compounds. Significant knowledge gaps...

The role of the parasympathetic nervous system in visually induced motion sickness: systematic review and meta-analysis.

The parasympathetic nervous system (PNS) has been implicated in the development of visually induced motion sickness. The objective of this study was to perform a systematic review and meta-analysis of the effect of visually induced motion sickness on validated parameters of PNS tone. Methods followed PRISMA recommendations. Controlled trials reporting validated measures of PNS tone in visually induced motion sickness in healthy adults were included. One reviewer performed the screening of articles and data extraction, and two reviewers independently performed methodological evaluation. Data were synthesised using standardised mean differences (SMDs) for all relevant outcomes using a random-effects model. Publication bias was assessed via funnel plots and Egger's test. The search strategy identified seven citations comprising 237 healthy individuals. The mean quality score was 4/10 (range 3-7). There was no difference between baseline PNS tone between individuals who developed visually induced motion sickness and those that did not. Visually induced motion sickness (VIMS)-sensitive individuals had a reduction in PNS tone, following exposure to the stimulus (mean weighted SMD = -0.45, 95% confidence interval -0.64 to -0.27, Z = -4.8, p < 0.0001). There was no evidence of heterogeneity or publication bias. These data suggest that baseline PNS parameters do not provide a useful measure of predicting the probability of developing visually induced motion sickness. However, a fall in PNS tone, as indicated by cardiac activity, is characteristic in sensitive individuals. Further work is needed to characterise these responses in clinical populations, in conjunction with improvements and standardisation in study design.

Does visual fatigue from 3D displays affect autonomic regulation and heart rhythm?

Most investigations into the negative effects of viewing stereoscopic 3D content on human health have addressed 3D visual fatigue and visually induced motion sickness (VIMS). Very few, however, have looked into changes in autonomic balance and heart rhythm, which are homeostatic factors that ought to be taken into consideration when assessing the overall impact of 3D video viewing on human health. In this study, 30 participants were randomly assigned to two groups: one group watching a 2D video, (2D-group) and the other watching a 3D video (3D-group). The subjects in the 3D-group showed significantly increased heart rates (HR), indicating arousal, and an increased VLF/HF (Very Low Frequency/High Frequency) ratio (a measure of autonomic balance), compared to those in the 2D-group, indicating that autonomic balance was not stable in the 3D-group. Additionally, a more disordered heart rhythm pattern and increasing heart rate (as determined by the R-peak to R-peak (RR) interval) was observed among subjects in the 3D-group compared to subjects in the 2D-group, further indicating that 3D viewing induces lasting activation of the sympathetic nervous system and interrupts autonomic balance.

Pleasant music as a countermeasure against visually induced motion sickness

Visually induced motion sickness (VIMS) is a well-known side-effect in virtual environments or simulators. However, effective behavioral countermeasures against VIMS are still sparse. In this study, we tested whether music can reduce the severity of VIMS. Ninety-three volunteers were immersed in an approximately 14-minute-long video taken during a bicycle ride. Participants were randomly assigned to one of four experimental groups, either including relaxing music, neutral music, stressful music, or no music. Sickness scores were collected using the Fast Motion Sickness Scale and the Simulator Sickness Questionnaire. Results showed an overall trend for relaxing music to reduce the severity of VIMS. When factoring in the subjective pleasantness of the music, a significant reduction of VIMS occurred only when the presented music was perceived as pleasant, regardless of the music type. In addition, we found a gender effect with women reporting more sickness than men. We assume that the presentation of pleasant music can be an effective, low-cost, and easy-to-administer method to reduce VIMS.

Evaluation of Human Factors for the Next-Generation Displays: A Review of Subjective and Objective Measurement Methods

Objective: This study aimed to investigate important human factors that should be considered when developing ultra-high definition TVs by reviewing measurement methods and main characteristics of ultra-high definition displays. Background: Although much attention has been paid to high-definition displays, there have been few studies for systematically evaluating human factors. Method: In order to determine human factors to be considered in developing human-friendly displays, we reviewed subjective and objective measurement methods to figure out the current limitations and establish a guideline for developing human-centered ultra-high definition TVs. In doing so, pros and cons of both subjective and objective measurement methods for assessing humans factors were discussed and specific aspects of ultra-high definition displays were also investigated in the literature. Results: Hazardous effects such as visually-induced motion sickness, visual fatigue, and mental fatigue in the brain caused by undesirable TV viewing are induced by not only temporal decay of visual function but also cognitive load in processing sophisticated external information. There has been a growing evidence that individual differences in visual and cognitive ability to process external information can make contrary responses after exposing to the same viewing situation. A wide vision, ultra-high definition TVs provide, can has positive and negative influences on viewers depending on their individual characteristics. Conclusion: Integrated measurement methods capable of considering individual differences in human visual system are required to clearly determine potential effects of super-high vision displays with a wide view on humans. All of brainwaves, autonomic responses, eye functions, and psychological responses should be simultaneously examined and correlated. Application: The results obtained in this review are expected to be a guideline for determining optimized viewing factors of ultra-high definition displays and accelerating successful penetration of the next-generation displays into our daily life.

Frequency Characteristics of Visually Induced Motion Sickness

The aim of this study was to explore the frequency response of visually induced motion sickness (VIMS) for oscillating linear motion in the fore-and-aft axis. Simulators, virtual environments, and commercially available video games that create an illusion of self-motion are often reported to induce the symptoms seen in response to true motion. Often this human response can be the limiting factor in the acceptability and usability of such systems. Whereas motion sickness in physically moving environments is known to peak at an oscillation frequency around 0.2 Hz, it has recently been suggested that VIMS peaks at around 0.06 Hz following the proposal that the summed response of the visual and vestibular self-motion systems is maximized at this frequency. We exposed 24 participants to random dot optical flow patterns simulating oscillating fore-and-aft motion within the frequency range of 0.025 to 1.6 Hz. Before and after each 20-min exposure, VIMS was assessed with the Simulator Sickness Questionnaire. Also, a standard motion sickness scale was used to rate symptoms at 1-min intervals during each trial. VIMS peaked between 0.2 and 0.4 Hz with a reducing effect at lower and higher frequencies. The numerical prediction of the "crossover frequency" hypothesis, and the design guidance curve previously proposed, cannot be accepted when the symptoms are purely visually induced. In conditions in which stationary observers are exposed to optical flow that simulates oscillating fore-and-aft motion, frequencies around 0.2 to 0.4 Hz should be avoided.

Visually induced motion sickness and presence in videogames: The role of sound

Visually induced motion sickness (VIMS) is a well-known phenomenon in virtual environments, simulators, and videogames. We conducted an experiment to analyze the role of sound on the severity of VIMS and the feeling of presence in videogames. Thirty-two subjects first watched a pre-recorded sequence of the game “Mirrors Edge” and then played the game actively. Game-play sound was activated for half of the participants. VIMS was measured via the Simulator Sickness Questionnaire and the Fast Motion Sickness Scale, presence was captured using the Presence Questionnaire. Results showed severe VIMS in all participants during the passive video session, whereas active-play revealed only moderate VIMS. However, in both conditions sound turned out to have no effect, neither on the severity of VIMS nor on the amount of presence. We found a moderate negative correlation between VIMS and presence. The results indicate that sound is less important than often thought.

Effects of foveal retinal slip on visually induced motion sickness: a pilot study

This experiment isolated and studied the effects of eye motions on visually induced motion sickness (VIMS) from the effects of foveal retinal slip velocity on VIMS. Eye motion has been shown to contribute to motion sickness. However, most previous work manipulated eye motion using eye fixation pointer. In so doing eye motion suppression was co-founded with increase in the relative velocity between the eyes and the visual stimulus (retinal slip velocity). Retinal slip is a necessary condition in perception of visual motion and could affect VIMS. However, due to difficulties in controlling eye motion in isolation of retinal slip, few work examined this topic. Guo et al. (2011) studied the effect of eye motion by controlling retinal slip velocity and showed that eye motion can still have significant effects on VIMS after retinal slip velocity is controlled. In this study, four conditions represent the factorial combinations of high (+) and low (-) levels of eye motions (EM) and foveal retinal slip velocity (FRSV). Peripheral retinal slip velocity was kept the same throughout the four conditions. A real time eye-slaved pointer was used to achieve the design and presentation of the conditions. Eight subjects participated in the experiment and within subject design was used. Results of Wilcoxon signed rank tests on preliminary data indicated that reduction of foveal retinal slip while keeping eye movements and peripheral retinal slip the same can significantly reduce levels of VIMS (post-exposure total simulator sickness questionnaire scores: p &lt; 0.02 and 7-point nausea ratings: p &lt; 0.05). Implications of these preliminary results are discussed in the paper.

Developing an evaluation system of visually induced motion sickness for safe usage of moving images

We have developed an evaluation system of moving images by estimating temporal variations of discomfort levels of visually induced motion sickness (VIMS) caused by the images. The system is useful for making image producers understand the importance of reducing the possibility of VIMS. This activity will provide an environment that allows people to use moving images at ease in a variety of fields, such as entertainment, education and medical services. The system was developed by the collaborative research of image analysis, image producing and measurements of biomedical effects to apply the basic characteristics of VIMS for evaluating general images.

Effect of An Hour-Long Stereoscopic Film on Human Body

Three-dimensional (3D) television sets are available in the market and are becoming increasingly popular among consumers. However, viewing 3D films has potential adverse effects such as asthenopia and visually induced motion sickness (VIMS). The phenomenon of VIMS is not fully understood yet. One cause of VIMS has been considered to be sensory conflict, ie,, the disagreement between vergence and visual accommodation, while viewing a stereoscopic film. VIMS can be analyzed in subjective and physiological terms. The aim of this study is to evaluate the effect of viewing a long stereoscopic film on the human body. An electrocardiogram was obtained for subjects viewing an hour-long stereoscopic film. We also conducted stabilometric analysis for the subjects in the Romberg posture, flicker tests, and subjective questionnaires to detect fatigue and eye strain every 20 minutes. Statistical significance was observed for subjective averages of the test results obtained before exposure to the film and 40 minutes after the initiation of the measurement (p < 0.05). Symptoms of VIMS could be detected during the exposure to the hour-long 3D film. Based on this result, guidelines will be devised to ensure safety in viewing 3D movies.

Effects of Eye Fixation on Visually Induced Motion Sickness: Are they Caused by Changes in Retinal Slip Velocity?

Watching slowly moving wide field-of-view patterns can cause symptoms of visually induced motion sickness (VIMS) in viewers. A within-subject full factorial experiment was designed to test two hypotheses: 1) when watching patterns rotating at 60 degrees per second (dps), eye fixation increases the peripheral retinal slip velocity leading to a reduction in the levels of VIMS; and 2) when watching patterns rotating at 7 dps, eye fixation increases the peripheral retinal slip velocity leading to an increase in the levels of VIMS. The experimental design used two levels of eye fixation (with and without). Nine participants (4 male and 5 female) were exposed to all four conditions with a week’s break between each condition. Results indicated that when watching patterns rotating at 60 dps, eye fixation significantly increased the peripheral retinal slip velocity from 35 dps to 60 dps and reduced the levels of mean nausea from 3.6 to 2.7 (p < 0.01). When watching patterns rotating at 7 dps, eye fixation signific...

Evaluation of temporal relationship between a physiological index and a subjective score using average mutual information

Recently, because of the ubiquitous popularization of home video cameras, countless people have had opportunities to watch video images captured by amateur cameramen. Because of this, concerns have arisen over potential negative impacts on viewer health, such as visually-induced motion sickness (VIMS). To determine the mechanism inducing VIMS and to establish a method of preventing it, it is necessary to understand which types of video scenes are associated with the onset of VIMS. Furthermore, while it is useful to consider viewer self-assessments while watching such scenes, physiological indices can provide even more information because they can be measured second-by-second in real time. However, there is not much knowledge regarding the temporal relationships between the severity of VIMS and its accompanying physiological conditions. In this study, the average mutual information was employed to determine the temporal relationship between subjective evaluation scores (a subject’s personal evaluation of his/her own condition) and various physiological indices present when people suffer from VIMS. Our analysis of experimental data found that changes in the two physiological indices, which were respiratory sinus arrhythmia and the maximum cross-correlation coefficient between heart rate and pulse transmission time, had a concordance rate of more than 60% with changes in the severity of VIMS symptoms experienced by test subjects. Furthermore, we determined that it may be possible to detect signs of impending VIMS prior to the development of symptoms by analyzing physiological indices.

The Relationship between Spatial Velocity, Vection, and Visually Induced Motion Sickness: An Experimental Study

Spatial velocity (SV), a product of scene complexity and navigation velocity, is a metric to quantify virtual scene movement for the study of visually induced motion sickness (VIMS) (So et al., 2001). As SV increases, VIMS increases, peaks, and then decreases. Watching VIMS provoking stimuli of similar SV is hypothesized to produce similar levels of vection and VIMS. An experiment was conducted to test the hypothesis. Ten participants were exposed to five visual motion oscillating along fore-and-aft axis at different frequencies (from 0.05 to 0.8Hz). The r.m.s. velocity was kept constant and the frequency changes were achieved by changing the amplitudes of oscillation. These five stimuli had similar SVs. To our surprise, participants reported significantly different vection as the frequency increased even though the SVs were kept the same (p < 0.001). Levels of VIMS was not significantly different because the exposure duration was too short (20 seconds). A second experiment using stimuli with 30 minutes was conducted. Preliminary results indicated that levels of nausea significantly changed when viewers were exposed to visual oscillations with similar SVs but different frequency. Modifications to the previously reported SV metric are proposed.

The Effects of Optokinetic Nystagmus on Visually Induced Motion Sickness after the Confounding Effects of Retinal Slip is Controlled

Ebenholtz (1994) predicts that eye movement is a major cause of visually induced motion sickness (VIMS). This paper examines the effects of optkinetic nystagmus (OKN) on VIMS. Past studies had shown that reducing OKN with eye fixation could significantly reduce levels of VIMS. However, the reduction of OKN was confounded with increases in the velocity of image motion projected on viewers' retina (peripherial retinal slip velocity; PRSV). When watching alternating black-and-white vertical stripe rotating at 60 degrees-per-second along the yaw axis, increases in retinal slip velocity have been shown to reduce levels of VIMS (Hu et al., 1989). A within-subject experiment was conducted to study the effects of eye fixation on VIMS with and without the control of the PRSV. After controlling the confounding effect of increasing PRSV, reduction of OKN by eye fixation significantly reduced levels of VIMS as measured by normalized ratio-scale data (p = 0.017), mean 7-point nausea ratings (p = 0.006), and post simulator-sickness-questionnaire scores (p = 0.002). This finding is new and original. It suggests that eye movement by itself rather than its modulating effects on retinal slip velocity is responsible for increases in levels of VIMS. Implications of the results are discussed.

Visually induced motion sickness: Single- versus dual-axis motion

The majority of studies into visually induced motion sickness (VIMS) either use complex motion scenarios or are limited to single-axis motion. This study compared VIMS during single- and dual-axis motion. Twelve participants were exposed to (i) oscillating roll motion, (ii) linear motion in the fore-and-aft axis, and (iii) spiral motion, i.e. the summed direction of both of these flow vectors. Increased sensory conflict during exposure to spiral motion was hypothesised to increase the level of VIMS compared with exposure to its constituent motion patterns in isolation. Unexpectedly, spiral motion was not found to be more provocative than either of the two single-axis motion patterns, and this finding appears to be inconsistent with VIMS being determined by simple summation of the provocative stimuli. In the spiral motion condition, an atypical decrease in VIMS was observed during exposure, which was consistently preceded by a reduction in reported vection. It was hypothesised that the abstract nature as well as the unusual motion profile in the spiral motion condition may have rendered the stimulus increasingly ‘improbable’ and ultimately being disregarded, or ‘quarantined’, as an orientation cue by the central nervous system. The results are discussed in the context of methodological consequences for VIMS research and potential limitations of the use of abstract stimuli.

A pilot application of a questionnaire to evaluate visually induced motion sickness in spectators of tri-dimensional (3D) movies

Background: The increasing popularity of tri-dimensional (3D) movies has raised public concern and media interest about the safety of projected images for spectators. No specific instrument exists to assess the occurrence of visually induced motion sickness (VIMS) symptoms in 3D movie spectators in movie theaters. Methods: We developed a questionnaire containing 20 items divided into socio demographics, individual characteristics, movie vision characteristics and VIMS symptoms (during, right after, and at two hours from the viewing of the movie ). The questionnaire was self administered to 38 subjects, asking them to report time taken for its completion, comments and eventual difficulties in interpreting items. Results: Poor understanding or problems in identifying the correct item choice were noted for 4 questions belonging to the socio demographics section that were simplified in the final version of the questionnaire. Two other questions were merged into one after homogeneity analysis. Most VIMS symptoms were observed during the movie and quickly thereafter. Tired eyes was the symptom most often reported (39.5% of responders) followed by headache (18.4%), dizziness (18.4%) and nausea (15.8%). Double vision and palpitation were reported with very low frequency (respectively 5.3% and 2.3%) and vomit was not reported by any respondent. Homogeneity of symptom items was good (Cronbach alpha= 0.69). Reliability analysis showed satisfactory item-total correlations (alpha coefficient ranging from 0.61 to 0.73). Conclusions: The refined survey questionnaire can be applied in future studies to assess the frequency of VIMS symptoms in spectators of 3D movies and to identify the risk factors connected to inter-individual differences in susceptibility and to the characteristics of the movie viewing.