Effect of magnitude and direction of horizontal oscillation on motion sickness

BACKGROUND: Various types of motion and visual scene can cause motion sickness, but sickness in land transport seems to be often associated with variations in horizontal acceleration. If horizontal oscillation causes sickness, it seems reasonable to assume that greater amounts of motion (i.e., an increased magnitude of motion or an increased duration of motion) will increase the extent of the sickness. HYPOTHESIS: It was hypothesized that the magnitude, direction, and duration of horizontal oscillation would affect the sickness experienced by subjects. METHOD: The 144 subjects were exposed to horizontal sinusoidal oscillation at a frequency of 0.315 Hz while seated in a closed cabin with their eyes open for up to 30 min. Subjects were exposed to one of 12 conditions with either fore-and-aft or lateral oscillation at magnitudes of either: (i) 0.28 ms(-2) rms, (ii) 0.56 ms(-2) rms, (iii) 0.70 ms(-2) rms, (iv) 0.89 ms(-2) rms, (v) 1.11 ms(-2) rms, or (vi) a stationary control condition. Subjects provided ratings of their motion sickness symptoms at 1-min intervals during the 30-min exposures. RESULTS: At a frequency of 0.315 Hz, an increase in either the magnitude or the duration of horizontal oscillation resulted in increases in the incidence of motion sickness. There were significant positive correlations between self-ratings of motion sickness susceptibility provided by subjects before participating in the experiment and their illness ratings during the experiment. CONCLUSIONS: At a frequency of 0.315 Hz, motion sickness caused by horizontal oscillation increases with increases in the magnitude and duration of horizontal oscillation. For the conditions of this study, the sickness was similar with fore-and-aft and lateral oscillation.     

Effect of frequency and direction of horizontal oscillation on motion sickness

BACKGROUND: Low frequency horizontal oscillation can cause motion sickness in some transportation systems, but the influence of the frequency, magnitude, direction, and duration of oscillation are poorly understood. Hypothesis: It was hypothesized that motion sickness was independent of the direction of horizontal oscillation (fore-and-aft or lateral) and that there was no difference in the motion sickness produced by different frequencies of horizontal oscillation (between 0.2 and 0.8 Hz) when subjects were exposed to the same peak velocity of motion at each frequency. METHOD: The 192 subjects were exposed within a closed cabin to sinusoidal oscillation with a velocity of +/- 0.50 ms(-1). Each subject experienced up to 30 min of motion while sitting with eyes open on a seat with a low backrest. The 16 conditions involved either fore-and-aft or lateral oscillation at 8 different frequencies: (i) 0.20 Hz, (ii) 0.25 Hz, (iii) 0.315 Hz, (iv) 0.40 Hz, (v) 0.50 Hz, (vi) 0.63 Hz, (vii) 0.80 Hz, or (viii) a stationary control condition. Subjects provided ratings of their motion sickness symptoms at 1-min intervals during the 30-min exposures. RESULTS: Each frequency of oscillation produced significantly more sickness than the static control conditions. Overall, there were no significant differences in the sickness produced by the seven different frequencies or between the sickness produced by fore-and-aft or lateral oscillation. Self-ratings of motion sickness susceptibility provided by subjects before participating in the experiment were positively correlated with their illness ratings during the experiment. CONCLUSIONS: With horizontal oscillation over the range 0.2 to 0.8 Hz, motion sickness is very approximately dependent on the peak velocity of oscillation. An acceleration frequency weighting having a gain inversely proportional to frequency would provide a convenient simple method of evaluating this type of motion in transport. However, the results suggest that a more complex weighting, reflecting decreased nauseogenicity at higher and lower frequencies would be more accurate. The direction of motion (i.e., fore-and-aft or lateral) had no effect on the sickness experienced.     

Effect of roll oscillation frequency on motion sickness

BACKGROUND: In many environments associated with motion sickness there are low frequency motions in several axes, including roll. Roll motion has often been assumed to be a cause of motion sickness, either alone or in combination with motions in other axes. However, there have been no systematic studies of the effects of roll frequency on sickness. HYPOTHESIS: It was hypothesized that sickness caused by roll oscillation would depend on the frequency of roll. METHOD: There were 100 male subjects (aged 18 to 26 yr) who participated in a laboratory study. Prior to experiencing motion, all subjects completed a motion sickness history questionnaire giving information on travel and motion sickness experience. The seated subjects were exposed within a closed cabin to 30 min of sinusoidal roll motion at one of five frequencies: 0.025 Hz, 0.05 Hz, 0.10 Hz, 0.20 Hz, or 0.40 Hz. At each frequency, the cabin oscillated through +/-8 degrees about a center of rotation located on the seat surface. Ratings of motion sickness were obtained at 1-min intervals. RESULTS: Subject illness ratings were positively correlated with their previous motion sickness, although at each frequency the amount of sickness was small. Overall, there was no significant difference in the sickness ratings produced by the five motions. CONCLUSIONS: The frequency dependence of motion sickness produced by roll oscillation differs from that associated with vertical and horizontal oscillation. Motion sickness associated with pure roll oscillation of a seat will usually be less than the sickness associated with pure translational oscillation of the seat or the sickness associated with combined translation and rotation.     

A motion sickness maximum around the 0.2 Hz frequency range of horizontal translational oscillation

BACKGROUND: Low frequency translational oscillation can provoke motion sickness in land vehicles, ships and aircraft. Although controlled motion experiments indicate a progressive increase in nauseogenicity as frequency decreases toward 0.2 Hz, few data are available on the existence of a definite maximum nauseogenic potential of motion around 0.2 Hz, or decreased nauseogenicity below this frequency. HYPOTHESIS: Nauseogenicity should be maximal around 0.2 Hz. METHODS: We selected 12 subjects for high motion sickness susceptibility, and they were exposed to horizontal sinusoidal motion (1.0 m.s(-2) peak acceleration) at 3 different frequencies (0.1, 0.2 and 0.4 Hz), at 1-wk intervals at the same time of day, according to a factorial design. Subjects were seated comfortably in the upright position with head erect. Fore-aft motion was through the body and head X-axis. Motion was stopped (motion endpoint) at moderate nausea or after 30 min. RESULTS: The proportion of subjects experiencing moderate nausea was maximal at the intermediate frequency: 8/12 at 0.1 Hz, 12/12 at 0.2 Hz, 7/12 at 0.4 Hz. The mean time to motion endpoint was significantly (p < 0.01) shorter at the intermediate frequency: 18.0 min at 0.1 Hz; 11.2 min at 0.2 Hz; 20.2 min at 0.4 Hz. Similar frequency patterns emerged for other sickness ratings. The equivalent times to achieve moderate nausea using estimated values to correct for subjects who reached the 30 min time cut-off were: 22.7 min at 0.1 Hz; 11.2 min at 0.2 Hz; 28.1 min at 0.4 Hz. CONCLUSIONS: A maximum nauseogenic potential around 0.2 Hz was substantiated.     

Some influences of vision on susceptibility to motion sickness.

Two experiments were performed to evaluate the influence of vision on susceptibility to motion sickness during exposure to constant patterns of vestibular stimulation. The motion profile involved accelerating subjects at 20 degrees/s2 to 300 degrees/s, maintaining them at that constant velocity for 30 s, and decelerating them to a rapid stop in about 1.5 s. The number of stops tolerated by a subject before reaching the motion sickness endpoint served as his score. In Experiment 1, subjects were tested twice with their eyes open and twice with their eyes blindfolded. They tolerated fewer sudden stops when permitted sight of the experimental chamber. In Experiment 2, the effect of having the eyes-open or closed at different stages of the motion profile was evaluated. Having the eyes open during any stage of the test was more stressful than having the eyes closed, but this was especially true during the sudden stops. The findings are discussed in terms of their general implications for understanding a) situations in which vision alone elicits symptoms of motion sickness, and b) situations involving vestibular stimulation where vision heightens susceptibility.     

Locomotion and motion sickness during horizontally and vertically reversed vision

Locomotion and motion sickness during reversed vision were studied in ten normal subjects and a patient with bilateral labyrinthine loss. Whereas horizontal reversal produced moderate to severe gait disturbances as well as motion sickness in all normal subjects, vertical reversal failed to induce such symptoms. The patient, being free of motion sickness during both reversals, could not walk straight during horizontal reversal. The difference in the strength of sensory mismatch between both directions seemed to result from a difference in the role of vision for spatial orientation which is produced by the proprioceptive as well as otolithic inputs of gravity.     

Rotation direction change hastens motion sickness onset in an optokinetic drum

BACKGROUND: Many stationary subjects who view the patterned interior of a rotating cylinder (optokinetic drum) experience motion sickness (MS) symptoms. An experiment was conducted to investigate the effects of rotation direction change on MS onset and severity. It was predicted that intermittently changing rotation direction would hasten MS onset due to an increased degree of visual/vestibular sensory conflict. METHODS: There were 12 individuals who participated in the experiment (4 men, 8 women, mean age = 24.4 yr). Subjects viewed the interior of an optokinetic drum that rotated at 5 rpm (30 degrees x s(-1)). Drum rotation was either consistently in the same direction or rotation direction changed every 30 s. Eight MS symptoms were assessed at 2-min intervals using a subjective scale (0 = none, 1 = slight, 2 = moderate, 3 = severe). RESULTS: Overall, MS onset was fastest when drum rotation direction changed. Specific MS symptoms significantly affected were dizziness, stomach awareness, and nausea. CONCLUSIONS: These results suggest that a lack of correlation between the sensed and expected effects of motion alone can lead to MS. These results cannot be accounted for by a lack of correlation between sensed and expected gravitational vertical given that these were held constant across conditions.     

Eye movements to yaw, pitch, and roll about vertical and horizontal axes: adaptation and motion sickness

BACKGROUND: In the search for parameters to predict motion sickness that can be measured in the laboratory, we performed a longitudinal investigation in aviators. Since the vestibular system is involved in the generation of motion sickness as well as eye movements, vestibulo-ocular reflex (VOR) parameters seemed relevant. We investigated three topics: 1) the effect of axis orientation and its orientation to gravity on the VOR; 2) changes in VOR parameters depending on flight experience; and 3) differences in VOR parameters in aircrew with high and low susceptibility to motion sickness. HYPOTHESIS: Nystagmus decay after angular velocity steps would be faster for non-susceptible and trained aviators. METHODS: We recorded eye movements evoked by angular on-axis velocity steps (+/- 90 degrees x S(-2), to and from 90 degrees x S(-1)) in yaw, pitch, and roll, about both the Earth vertical and Earth horizontal axes in 14 subjects with a low susceptibility to motion sickness. These data were compared with those of 10 subjects with a high susceptibility. RESULTS: Horizontal axis rotations are nauseogenic. We found that during (per) and post-condition, left- and rightward rotation responses were equal, and the orientation with respect to gravity did not alter the basic nystagmus decay, apart from a sinusoidal modulation. Moreover, pitch and roll rotations show equal nystagmus decays, significantly faster than for yaw; yaw and pitch peak velocities were equal and were larger than for roll. With regard to changes in VOR parameters depending on flight experience, we found that repeated vestibular stimulation reduced nystagmus decay as well as the otolith modulation. With respect to the changes in VOR parameters and motion sickness susceptibility, we found that subjects highly susceptible to motion sickness showed a slower decay of nystagmus with a larger peak velocity than less susceptible subjects. CONCLUSIONS: Group averages indicate a difference in eye movement parameters, only in yaw, depending on flight experience; and between subjects with low and high susceptibility to motion sickness. The involvement of the velocity storage mechanism as realized by an internal model is given as a plausible explanation.     

Optokinetic nystagmus,vection, and motion sickness

BACKGROUND: Two current theories concerning the etiology of motion sickness (MS)-the eye movement hypothesis and sensory conflict theory-were evaluated under conditions that manipulated the degree of optokinetic nystagmus (OKN) and/or vection. METHOD: Eye movement and perceptual responses were elicited with whole field stimulation in a vertically striped rotating drum and modulated with fixation and/or a restriction of the field of view (FOV). Measures of OKN, vection, and MS were recorded under the various conditions. RESULTS: Both visual field restriction and/or fixation diminished circular vection, OKN, and MS. Conditions involving both fixation and restricted FOV resulted in greater reductions in MS than did either restriction alone. CONCLUSIONS: These findings lend support to a multi-factor explanation of MS, involving both sensory conflict and eye movement.     

既往运动病易感性对科里奥利加速度耐受性的影响

目的观察既往运动病易感性水平对科里奥利加速度耐受性是否有影响。方法采用运动病易感量表筛选58名不同运动病易感的健康志愿者,采用垂直轴旋转刺激(每秒钟60°顺时针旋转)使身体旋转,以恶心评定量表、恶心问卷和旋转耐受时间为指标观察不同易感者的症状程度和旋转耐受时间的差异。结果既往运动病易感组童年期运动病易感得分、成年期运动病易感得分、运动病易感总分均高于非易感组(P<0.01)。运动病易感组和非易感组旋转耐受时间差异无显著性意义。易感组旋转前、旋转后即刻、旋转后15 min、30 min恶心评定量表得分均高于非易感组,差异有显著性意义。易感组恶心问卷总分、消化道不适得分、情绪困扰得分高于非易感组,差异有非常显著性意义(P<0.01)。既往运动病易感性与旋转耐受时间不相关;与旋转前、旋转后即刻、旋转后15 min3、0 min恶心评定量表得分、恶心问卷总分、躯体不适得分、消化道不适得分和情绪困扰得分呈显著相关。结论既往运动病易感性影响科里奥利加速度耐受性,可作为试验性运动病的预测指标。     

Acupressure and motion sickness

The effectiveness of the "Sea Band" acupressure band compared with placebo and hyoscine (0.6 mg), also known as scopolamine, to increase tolerance to a laboratory nauseogenic cross-coupled motion challenge was assessed using 18 subjects. The results showed that the subjects had a significant increase in tolerance with hyoscine but had no increase in tolerance with the "Sea Band" or placebo. Possible reasons for the failure to show any significant protection from the use of these acupressure bands are insufficient movement of the wrist to provide continuous stimulation, and/or the likelihood that only a minority of the population would show non-negligible benefit as experience with medical acupressure would suggest. The application of transcutaneous electrical nerve stimulation may be worthy of study.     

Tachygastria and motion sickness

Cutaneously-recorded electrogastrograms (EGGs) were obtained from 21 healthy volunteers who were seated within a drum, the rotation of which produced vection or illusory self-motion. Fourteen subjects developed symptoms of motion sickness during vection and in each the EGG frequency shifted from the normal 3 cpm to 5-8 cpm, tachygastria, an abnormal pattern. In 6 of 7 asymptomatic subjects, the 3 cpm EGG pattern was unchanged during vection. It was concluded that illusory self-motion produces tachygastria and motion sickness in susceptible subjects.     

运动病的研究进展

该文从运动病病因与发病机制、预测与评估等相关方面评述运动病的研究进展,为运动病的深入研究及采取相应对策,预防其发生、发展提供理论基础。     

低氧对视动刺激诱发的运动病的影响

为探讨中度低氧对视动刺激诱发运动病的影响及其特点和规律,２０岁１８￣２５岁的健康男性,按照“拉丁方”排列和“自身对照”法,进行了单纯视动刺激和低氧视动刺激试验。主要观察和记录了运动病症状及视动性水平眼震（ＯＫＨＮ）。结果显示：（１）低氧视动刺激（ＨＯＳ）的运动病症状得分显著高于单纯视动刺激（ＯＳ）时的得分（Ｐ〈０．００１）;（２）低氧视动刺激时的视动性水平眼震慢相速度（ＳＰＶ）显著小于单纯视动刺激     

Gender differences in motion sickness history and susceptibility to optokinetic rotation-induced motion sickness

PURPOSE: The present study investigated gender differences in motion sickness history and susceptibility to optokinetic rotation-induced motion sickness. METHODS AND RESULTS: The study included two phases. In Phase 1, 485 subjects filled out a survey of previous incidence of motion sickness. Results indicated that women reported significantly greater incidence of feeling motion sickness than did men on buses, on trains, on planes, in cars, and on amusement rides before the age of 12 yr; and on buses, on trains, on planes, in boats, on ships, in cars, on amusement rides, and on swings between the ages of 12 and 25 yr. Women also reported significantly higher incidence of being actually sick than did men on buses before the age of 12 yr and on buses, on ships, and in cars between the ages of 12 and 25 yr. In Phase 2, each of the 47 subjects viewed an optokinetic rotating-drum for 16 min. Subjects' subjective symptoms of motion sickness (SSMS) were obtained during drum rotation. The results showed that there were no significant differences on SSMS scores between men and women. CONCLUSION: Although women reported greater incidence in motion sickness history, women did not differ from men in severity of symptoms of motion sickness while viewing a rotating optokinetic drum.     

Vertical display oscillation effects on forward vection and simulator sickness

BACKGROUND: The current study investigated the effects that vertical display oscillation had on the development of both vection and simulator sickness. METHODS: There were 16 subjects who were exposed to optic flow displays which simulated either: 1) constant velocity forward self-motion (pure radial flow); or 2) combined constant velocity forward and vertically oscillating self-motion (radial flow with vertical oscillation at one of three frequencies: 1.8, 3.7, or 7.4 Hz). During each 10-min display exposure, subjects rated the strength of their vection and eight symptoms listed on the Subjective Symptoms of Motion Sickness (SSMS) scale at 2-min intervals. Subjects also completed the Simulator Sickness Questionnaire (SSQ) designed by Kennedy and colleagues before and after each trial, which generated a total SSQ score and three SSQ subscores (nausea, oculomotor symptoms, and disorientation). RESULTS: Vertically oscillating displays (mean = 5.51; SD = 2.5) were found to produce significantly stronger vection ratings than non-oscillating displays (mean = 3.56; SD = 2.1). Vertically oscillating displays (mean = 58.18; SD = 32.2) were also found to produce significantly more severe sickness (as rated by total SSQ scores) than non-oscillating displays (mean = 29.67; SD = 24.7). Both vection and sickness symptoms increased in magnitude with prolonged exposure to optic flow. CONCLUSIONS: Our findings appear to represent a special case in visual self-motion perception where high-frequency vertical oscillation both enhances vection and increases simulator sickness when it is incorporated into an optic flow display simulating constant velocity self-motion in depth.     

Effect of transdermally administered scopolamine in preventing motion sickness.

The efficacy of transdermally administered scopolamine was compared with the efficacy of oral dimenhydrinate and placebo therapy in the prevention of motion-induced mausea in a vertical oscillator; medications were administered on a double-blind cross-over basis, with the order of treatments counterbalanced. Thirty-five subjects known to be susceptible to the stimulus were utilized. A placebo effect reduced the motion sickness incidence (MSI) from 100% to 59%. Administration of dimenhydrinate reduced the MSI to 32%, and use of the transdermal therapeutic system scopolamine (TTS-scopolamine) further reduced the MSI TO 16%. TTS-scopolamine afforded 73% protection against motion-induced nausea, compared to 46% protection with dimenhydrinate. The TTS-scopolamine is designed to remain in the body for 72 hours, providing advantages over intramuscular or oral administration of scopolamine, which include reduced daily dosage, and an effective alternate to the gastrointestinal tract for administrating medication at times of gastrointestinal distress.