Showing papers on "Motion sickness published in 2014"
TL;DR: 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.
Abstract: 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.
207 citations
TL;DR: An overall trend for relaxing music to reduce the severity of VIMS was found and a gender effect with women reporting more sickness than men was found.
72 citations
TL;DR: It is proposed that conditions producing persistent activity of vestibular “sensory conflict” neurons, or their targets, stimulate nearby brainstem emetic centers—via an as yet unidentified mechanism.
Abstract: The origin of the internal "sensory conflict" stimulus causing motion sickness has been debated for more than four decades. Recent studies show a subclass of neurons in the vestibular nuclei and deep cerebellar nuclei that respond preferentially to passive head movements. During active movement, the semicircular canal and otolith input ("reafference") to these neurons are canceled by a mechanism comparing the expected consequences of self-generated movement (estimated with an internal model-presumably located in the cerebellum) with the actual sensory feedback. The un-canceled component ("exafference") resulting from passive movement normally helps compensate for unexpected postural disturbances. Notably, the existence of such vestibular "sensory conflict" neurons had been postulated as early as 1982, but their existence and putative role in posture control and motion sickness have been long debated. Here, we review the development of "sensory conflict" theories in relation to recent evidence for brainstem and cerebellar reafference cancelation, and identify some open research questions. We propose that conditions producing persistent activity of these neurons, or their targets, stimulate nearby brainstem emetic centers-via an as yet unidentified mechanism. We discuss how such a mechanism is consistent with the notable difference in motion sickness susceptibility of drivers as opposed to passengers, human immunity to normal self-generated movement and why head restraint or lying horizontal confers relative immunity. Finally, we propose that fuller characterization of these mechanisms and their potential role in motion sickness could lead to more effective, scientifically based prevention and treatment for motion sickness.
62 citations
TL;DR: The results of the analysis showed that the simulator test conditions affect in different ways the severity of the simulator sickness symptoms, depending on the time which has elapsed since performing the task on the simulator.
61 citations
Journal Article•
TL;DR: Patients should learn to identify situations that will lead to motion sickness and minimize the amount of unpleasant motion they are exposed to by avoiding difficult conditions while traveling or by positioning themselves in the most stable part of the vehicle.
Abstract: Motion sickness is a common syndrome that occurs upon exposure to certain types of motion. It is thought to be caused by conflict between the vestibular, visual, and other proprioceptive systems. Although nausea is the hallmark symptom, it is often preceded by stomach awareness, malaise, drowsiness, and irritability. Early self-diagnosis should be emphasized, and patients should be counseled about behavioral and pharmacologic strategies to prevent motion sickness before traveling. Patients should learn to identify situations that will lead to motion sickness and minimize the amount of unpleasant motion they are exposed to by avoiding difficult conditions while traveling or by positioning themselves in the most stable part of the vehicle. Slow, intermittent exposure to the motion can reduce symptoms. Other behavioral strategies include watching the true visual horizon, steering the vehicle, tilting their head into turns, or lying down with their eyes closed. Patients should also attempt to reduce other sources of physical, mental, and emotional discomfort. Scopolamine is a first-line medication for prevention of motion sickness and should be administered transdermally several hours before the anticipated motion exposure. First-generation antihistamines, although sedating, are also effective. Nonsedating antihistamines, ondansetron, and ginger root are not effective in the prevention and treatment of motion sickness.
57 citations
TL;DR: The incidence of motion sickness was greater in the Touch condition than in the Tilt condition, and movement of the head and torso differed as a function of the type of game control.
Abstract: Drivers are less likely than passengers to experience motion sickness, an effect that is important for any theoretical account of motion sickness etiology. We asked whether different types of control would affect the incidence of motion sickness, and whether any such effects would be related to participants’ control of their own bodies. Participants played a video game on a tablet computer. In the Touch condition, the device was stationary and participants controlled the game exclusively through fingertip inputs via the device’s touch screen. In the Tilt condition, participants held the device in their hands and moved the device to control some game functions. Results revealed that the incidence of motion sickness was greater in the Touch condition than in the Tilt condition. During game play, movement of the head and torso differed as a function of the type of game control. Before the onset of subjective symptoms of motion sickness, movement of the head and torso differed between participants who later reported motion sickness and those that did not. We discuss implications of these results for theories of motion sickness etiology.
55 citations
31 Dec 2014
TL;DR: Evidence from human and animal experiments indicates that the physiological mechanisms responsible for the motion sickness-induced hypothermia include cutaneous vasodilation and sweating (leading to an increase of heat loss and reduced thermogenesis), which suggest that motion sickness triggers highly coordinated physiological response aiming to reduce body temperature.
Abstract: Principal symptoms of motion sickness in humans include facial pallor, nausea and vomiting, and sweating. It is less known that motion sickness also affects thermoregulation, and the purpose of thi...
52 citations
27 Jan 2014
TL;DR: A methodology to evaluate the objective illness rating metrics deduced from the motion sickness dose value and questionnaires for both a static simulator and a dynamic simulator showed that the longitudinal head dynamics were the main element that induced discomfort for the static platform, whereas vertical head movements were themain factor to provoke discomfort forThe dynamic platform case.
Abstract: This paper deals with driving simulation and in particular with the important issue of motion sickness. The paper proposes a methodology to evaluate the objective illness rating metrics deduced from the motion sickness dose value and questionnaires for both a static simulator and a dynamic simulator. Accelerations of the vestibular cues (head movements) of the subjects were recorded with and without motion platform activation. In order to compare user experiences in both cases, the head-dynamics-related illness ratings were computed from the obtained accelerations and the motion sickness dose values. For the subjective analysis, the principal component analysis method was used to determine the conflict between the subjective assessment in the static condition and that in the dynamic condition. The principal component analysis method used for the subjective evaluation showed a consistent difference between the answers given in the sickness questionnaire for the static platform case from those for the dynamic platform case. The two-tailed Mann-Whitney U test shows the significance in the differences between the self-reports to the individual questions. According to the two-tailed Mann-Whitney U test, experiencing nausea (p = 0.019 < 0.05) and dizziness (p = 0.018 < 0.05) decreased significantly from the static case to the dynamic case. Also, eye strain (p = 0.047 < 0.05) and tiredness (p = 0.047 < 0.05) were reduced significantly from the static case to the dynamic case. For the perception fidelity analysis, the Pearson correlation with a confidence interval of 95% was used to study the correlations of each question with the x illness rating component IRx, the y illness rating component IRy, the z illness rating component IRz and the compound illness rating IRtot. The results showed that the longitudinal head dynamics were the main element that induced discomfort for the static platform, whereas vertical head movements were the main factor to provoke discomfort for the dynamic platform case. Also, for the dynamic platform, lateral vestibular-level dynamics were the major element which caused a feeling of fear.
45 citations
TL;DR: Multitasking cognitive performance declined even when motion sickness and soporific symptoms were mild, and an inverse relationship between motion sickness effects on performance and the cognitive effort focused on performing a task is suggested.
Abstract: Objective: In this study, we investigated the effects of mild motion sickness and sopite syndrome on multitasking cognitive performance. Background: Despite knowledge on general motion sickness, little is known about the effect of motion sickness and sopite syndrome on multitasking cognitive performance. Specifically, there is a gap in existing knowledge in the gray area of mild motion sickness. Method: Fifty-one healthy individuals performed a multitasking battery. Three independent groups of participants were exposed to two experimental sessions. Two groups received motion only in the first or the second session, whereas the control group did not receive motion. Measurements of motion sickness, sopite syndrome, alertness, and performance were collected during the experiment. Results: Only during the second session, motion sickness and sopite syndrome had a significant negative association with cognitive performance. Significant performance differences between symptomatic and asymptomatic participants in the second session were identified in composite (9.43%), memory (31.7%), and arithmetic (14.7%) task scores. The results suggest that performance retention between sessions was not affected by mild motion sickness. Conclusion: Multitasking cognitive performance declined even when motion sickness and soporific symptoms were mild. The results also show an order effect. We postulate that the differential effect of session on the association between symptomatology and multitasking performance may be related to the attentional resources allocated to performing the multiple tasks. Results suggest an inverse relationship between motion sickness effects on performance and the cognitive effort focused on performing a task. Application: Even mild motion sickness has potential implications for multitasking operational performance.
44 citations
TL;DR: It is demonstrated that the DB protocol can be used to significantly increase PNS tone and decrease the development of motion sickness symptoms.
Abstract: Evidence indicates that activation of the parasympathetic nervous system (PNS) suppresses physiological responses associated with motion sickness. Research also shows paced breathing increases PNS activation; the current study examines the use of paced diaphragmatic breathing (DB) training to quell motion sickness symptoms. Healthy participants (N = 60) were pre-screened for motion sickness susceptibility. Participants were then randomly assigned to either a control condition, focusing on environmental awareness, or to an experimental condition implementing paced DB. Following this, participants were exposed to a virtual reality (VR) motion sickness experience, while heart rate variability, breathing rate (RPM), and motion sickness ratings were collected. Results demonstrated participants in the DB condition had higher PNS activation and reported fewer motion sickness symptoms during the VR experience than the participants in the control condition. Results suggest that the DB protocol can be used to significantly increase PNS tone and decrease the development of motion sickness symptoms.
TL;DR: The prevalence of motion sickness in schoolchildren is greater when in a car or on a bus and an association was found between motion sickness and postural balance tests and motion sickness and quality of life.
Abstract: This study aimed to determine the prevalence of motion sickness in schoolchildren and related the finding to the postural balance and quality of life. A population-based cross-sectional study was carried out with 831 children aged 7 to 12 years. The frequency of motion sickness was evaluated based on the Motion Sickness Susceptibility Questionnaire-Short (MSSQ-short). Postural balance was assessed using the Romberg test under different sensory conditions. The Dizziness Handicap Inventory was used in order to assess the quality of life. The statistical analyses were performed using the chi-square, Kruskal–Wallis, Mann–Whitney, and Spearman correlation tests. The prevalence of motion sickness was 43.4 % in car, 43.2 % on bus, 11.7 % on park swing, and 11.6 % on Ferris wheel. Mean unadjusted scores on the MSSQ-short ranged from 5.0 (SE = 0.5) for 10-year-olds to 6.8 (SE = 0.5) for 9-year-olds. The most prevalent symptoms following the balance tests were dizziness (89.2 %), vertigo (54.9 %), headache (10.6 %), and nausea (8.2 %). Significant correlations were found between the MSSQ-short score and all postural balance tests. Significant correlations were found between the MSSQ and modified DHI (Dizziness Handicap Inventory) at all ages. Conclusion: The prevalence of motion sickness in schoolchildren is greater when in a car or on a bus. An association was found between motion sickness and postural balance tests and motion sickness and quality of life.
TL;DR: In conclusion, motion sickness is accompanied by hypothermia that involves both autonomic and thermoeffector mechanisms: tail-skin vasodilation and possibly reduction of the interscapular brown adipose tissue activity.
Abstract: // Sukonthar Ngampramuan 1 , Matteo Cerri 2 , Flavia Del Vecchio 2 , Joshua J. Corrigan 3 , Amornrat Kamphee 1 , Alexander S. Dragic 3 , John A. Rudd 4 , Andrej A. Romanovsky 3 , and Eugene Nalivaiko 5 1 Research Center for Neuroscience and Institute of Molecular Bioscience, Mahidol University, Bangkok, Thailand; 2 Department of Biomedical and Motor Sciences, University of Bologna, Bologna, Italy; 3 FeverLab, Trauma Research, St. Joseph’s Hospital and Medical Center, Phoenix, AZ, USA; 4 School of Biomedical Sciences, Chinese University of Hong Kong, Hong Kong, China; 5 School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, NSW, Australia. Correspondence: Eugene Nalivaiko, email: // Andrej A. Romanovsky, email: // Keywords : nausea, chemotherapy, temperature, hypothermia. Received : December 21, 2013 Accepted : February 21, 2014 Published : February 22 2014 Abstract Nausea is a prominent symptom and major cause of complaint for patients receiving anticancer chemo- or radiation therapy. The arsenal of anti-nausea drugs is limited, and their efficacy is questionable. Currently, the development of new compounds with anti-nausea activity is hampered by the lack of physiological correlates of nausea. Physiological correlates are needed because common laboratory rodents lack the vomiting reflex. Furthermore, nausea does not always lead to vomiting. Here, we report the results of studies conducted in four research centers to investigate whether nausea is associated with any specific thermoregulatory symptoms. Two species were studied: the laboratory rat, which has no vomiting reflex, and the house musk shrew (Suncus murinus), which does have a vomiting reflex. In rats, motion sickness was induced by rotating them in their individual cages in the horizontal plane (0.75 Hz, 40 min) and confirmed by reduced food consumption at the onset of dark (active) phase. In 100% of rats tested at three centers, post-rotational sickness was associated with marked (~1.5°C) hypothermia, which was associated with a short-lasting tail-skin vasodilation (skin temperature increased by ~4°C). Pretreatment with ondansetron, a serotonin 5-HT3 receptor antagonist, which is used to treat nausea in patients in chemo- or radiation therapy, attenuated hypothermia by ~30%. In shrews, motion sickness was induced by a cyclical back-and-forth motion (4 cm, 1 Hz, 15 min) and confirmed by the presence of retching and vomiting. In this model, sickness was also accompanied by marked hypothermia (~2°C). Like in rats, the hypothermic response was preceded by transient tail-skin vasodilation. In conclusion, motion sickness is accompanied by hypothermia that involves both autonomic and thermoeffector mechanisms: tail-skin vasodilation and possibly reduction of the interscapular brown adipose tissue activity. These thermoregulatory symptoms may serve as physiological correlates of nausea.
TL;DR: This study mapped the distribution of c-fos protein (Fos)-like immunoreactivity elicited during a galvanic vestibular stimulation paradigm that is known to induce motion sickness in felines.
Abstract: Motion sickness is a complex condition that includes both overt signs (e.g., vomiting) and more covert symptoms (e.g., anxiety and foreboding). The neural pathways that mediate these signs and symptoms are yet to identified. This study mapped the distribution of c-fos protein (Fos)-like immunoreactivity elicited during a galvanic vestibular stimulation paradigm that is known to induce motion sickness in felines. A principal components analysis was used to identify networks of neurons activated during this stimulus paradigm from functional correlations between Fos labeling in different nuclei. This analysis identified five principal components (neural networks) that accounted for greater than 95% of the variance in Fos labeling. Two of the components were correlated with the severity of motion sickness symptoms, and likely participated in generating the overt signs of the condition. One of these networks included neurons in locus coeruleus, medial, inferior and lateral vestibular nuclei, lateral nucleus tractus solitarius, medial parabrachial nucleus and periaqueductal gray. The second included neurons in the superior vestibular nucleus, precerebellar nuclei, periaqueductal gray, and parabrachial nuclei, with weaker associations of raphe nuclei. Three additional components (networks) were also identified that were not correlated with the severity of motion sickness symptoms. These networks likely mediated the covert aspects of motion sickness, such as affective components. The identification of five statistically independent component networks associated with the development of motion sickness provides an opportunity to consider, in network activation dimensions, the complex progression of signs and symptoms that are precipitated in provocative environments. Similar methodology can be used to parse the neural networks that mediate other complex responses to environmental stimuli.
TL;DR: Body sway was affected by loads and by load position, consistent with previous research, and sway differed between well and sick participants both before and during exposure to visual motion stimuli.
TL;DR: Results show that both the rotarod test and the modified balance beam test can be used to identify changes in balance performance during aging as an alternative to more difficult and invasive techniques such as vestibulo-ocular (VOR) measurements.
Abstract: Age related decline in balance performance is associated with deteriorating muscle strength, motor coordination and vestibular function. While a number of studies show changes in balance phenotype with age in rodents, very few isolate the vestibular contribution to balance under either normal conditions or during senescence. We use two standard behavioral tests to characterize the balance performance of mice at defined age points over the lifespan: the rotarod test and the inclined balance beam test. Importantly though, a custom built rotator is also used to stimulate the vestibular system of mice (without inducing overt signs of motion sickness). These two tests have been used to show that changes in vestibular mediated-balance performance are present over the murine lifespan. Preliminary results show that both the rotarod test and the modified balance beam test can be used to identify changes in balance performance during aging as an alternative to more difficult and invasive techniques such as vestibulo-ocular (VOR) measurements.
TL;DR: The present study is the first to demonstrate that motion sickness may be caused by pure auditory stimulation, which it refers to as “auditorily induced motion sickness”.
Abstract: Auditory cues can create the illusion of self-motion (vection) in the absence of visual or physical stimulation. The present study aimed to determine whether auditory cues alone can also elicit motion sickness and how auditory cues contribute to motion sickness when added to visual motion stimuli. Twenty participants were seated in front of a curved projection display and were exposed to a virtual scene that constantly rotated around the participant's vertical axis. The virtual scene contained either visual-only, auditory-only, or a combination of corresponding visual and auditory cues. All participants performed all three conditions in a counterbalanced order. Participants tilted their heads alternately towards the right or left shoulder in all conditions during stimulus exposure in order to create pseudo-Coriolis effects and to maximize the likelihood for motion sickness. Measurements of motion sickness (onset, severity), vection (latency, strength, duration), and postural steadiness (center of pressure) were recorded. Results showed that adding auditory cues to the visual stimuli did not, on average, affect motion sickness and postural steadiness, but it did reduce vection onset times and increased vection strength compared to pure visual or pure auditory stimulation. Eighteen of the 20 participants reported at least slight motion sickness in the two conditions including visual stimuli. More interestingly, six participants also reported slight motion sickness during pure auditory stimulation and two of the six participants stopped the pure auditory test session due to motion sickness. The present study is the first to demonstrate that motion sickness may be caused by pure auditory stimulation, which we refer to as "auditorily induced motion sickness".
TL;DR: Broadly inclusive studies of well-characterized patients with other neurotologic and psychiatric comorbidities are needed to fully understand how vestibular symptoms and migraine interact in order to truly validate Vestibular migraine, distill its essential features, define its boundaries, and characterize overlapping comorbiities.
Abstract: A growing body of clinical and epidemiological evidence supports a specific relationship between vestibular symptoms and migraine. Without a biomarker or complete understanding of pathophysiology, diagnosis of vestibular migraine (VM) currently depends upon symptoms in two dimensions: episodic vestibular symptoms temporally related to migraine symptoms. The Barany Society and the International Headache Society have recently developed consensus diagnostic criteria. However, many issues remain unsettled, including the type, duration, and timing of vestibular symptoms related to headache that should be required for diagnosing VM. This paper focuses on the challenging third dimension of comorbidity, a frequent cause of diagnostic uncertainty that may confound clinical application and research validation of VM criteria. Several other neurotologic conditions occur more frequently in migraineurs than controls, including benign paroxysmal positional vertigo, Meniere's disease, and motion sickness. Patients with VM also have high rates of chronic subjective dizziness, which may be associated with anxious, introverted temperaments that can affect clinical presentation and treatment response. Broadly inclusive studies of well-characterized patients with other neurotologic and psychiatric comorbidities are needed to fully understand how vestibular symptoms and migraine interact in order to truly validate vestibular migraine, distill its essential features, define its boundaries, and characterize overlapping comorbidities.
TL;DR: An overview of the multiple facets of the link between migraine and Vestibular dysfunction is given, which is complex and has many aspects beyond vestibular migraine.
Abstract: Purpose of review Awareness of the importance of migraine in patients with symptoms of vestibular dysfunction is increasing. This article gives an overview of the multiple facets of the link between migraine and vestibular dysfunction. Recent findings The vestibular and the headache community have published a consensual definition of vestibular migraine, which is an important step to promote research on the topic and the awareness of clinicians. Vestibular migraine is considered the most common cause of spontaneous recurrent vertigo. So far, the evidence for vestibular migraine has been mainly epidemiological, but the recent follow-up of a cohort over 9 years could show the robustness of the diagnosis over time.Additionally, migraine and vestibular dysfunction have multiple potential interactions and links through a range of comorbidities such as Meniere's disease, benign paroxysmal positional vertigo, anxiety and motion sickness, which go beyond the diagnostic entity of vestibular migraine. Summary The further refinement and wider acceptance of the diagnostic entity of vestibular migraine is an important development as it is one the most common vestibular disorders. But the relationship between migraine and vestibular dysfunction is complex and has many aspects beyond vestibular migraine.
TL;DR: A systematic review and meta-analysis of the effect of visually induced motion sickness on validated parameters of parasympathetic nervous system (PNS) tone was performed in this paper.
Abstract: 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.
TL;DR: The current study is the first to report that greater susceptibility to motion sickness is associated with larger cVEMP amplitudes and lower interaural cV EMP asymmetries and is consistent with the theory that vertical motions elicit motion sickness.
Abstract: BACKGROUND Motion sickness is a common debilitating condition associated with both actual and perceived motion. Despite the commonality, little is known about the underlying physiological mechanisms. One theory proposes that motion sickness arises from a mismatch between reality and past experience in vertical motions. Physiological tests of the vestibular system, however, have been inconclusive regarding the underlying pathogenesis. Cervical vestibular-evoked myogenic potentials (cVEMPs) arise from the saccule, which responds to vertical motion. If vertical motion elicits motion sickness, the cVEMP should be affected. PURPOSE The purpose of this investigation was to determine if cVEMP characteristics differ among individuals with a range of motion sickness susceptibility from negligible to severe. The hypothesis was that individuals with high susceptibility would have larger cVEMP amplitudes and shorter cVEMP latencies relative to those who are resistant to motion sickness. RESEARCH DESIGN The study had two parts. The first was quasi-experimental in which participants comprised three groups based on susceptibility to motion sickness (low, mild-moderate, high) as identified on the short version of the Motion Sickness Susceptibility Questionnaire (MSSQ-S). The second part of the study was correlational and evaluated the specific relationships between the degree of motion sickness susceptibility and characteristics of the VEMPs. STUDY SAMPLE A total of 24 healthy young adults (ages 20-24 yr) were recruited from the university and the community without regard to motion sickness severity. DATA COLLECTION AND ANALYSIS Participants took the MSSQ-S, which quantifies susceptibility to motion sickness. The participants had a range of motion sickness susceptibility with MSSQ raw scores from 0.0-36.6, which correspond to percent susceptibility from 0.0-99.3%. VEMPs were elicited by 500 Hz tone-bursts monaurally in both ears at 120 dB pSPL. MSSQ-S percent scores were used to divide the participants into low, mild-moderate, and high susceptibility groups. A fixed general linear model with repeated-measures analysis of variance tested cVEMP characteristics for the susceptibility groups (between participants) and ears (within participants). A univariate analysis of variance tested the cVEMP interaural amplitudes across groups. The second analysis was a regression of the severity of motion sickness in percent on cVEMP characteristics. Significance was defined as p < 0.05. RESULTS Participants in the high susceptibility group had significantly higher cVEMP amplitudes than those in the low susceptibility group. cVEMP amplitudes did not differ between ears, and latencies did not differ between the two groups or between ears. Regression analysis on MSSQ-S percent susceptibility by VEMP amplitudes revealed a best-fit cubic function in both ears, with r(2) values of more than 42%. The interaural asymmetry ratio was negatively associated with motion sickness susceptibility (r(2) = 0.389). CONCLUSIONS The current study is the first to report that greater susceptibility to motion sickness is associated with larger cVEMP amplitudes and lower interaural cVEMP asymmetries. Larger interaural asymmetries in cVEMPs did not promote motion sickness susceptibility. The cVEMP findings implicate the saccule and its neural pathways in the production of motion sickness and are consistent with the theory that vertical motions elicit motion sickness. Motion sickness susceptibility may contribute to the variability in normative cVEMP amplitudes.
TL;DR: The present study highlighted the lack of influence of odors in motion-induced sickness but an impact of a nauseogenic test on olfactory perception and showed that intensity of odor was significantly increased after OVAR and the intensity was significantly higher for unpleasant odors than for pleasant one.
TL;DR: The significant correlations found between motion sickness severity and mal de debarquement duration and severity imply that both syndromes might stem from a failure to adapt to new motion conditions, and there is a disparity between the previously reported reduction in motion sickness symptoms by an artificial horizon, and its failure to influence the duration and symptoms.
Abstract: BACKGROUND:Exposure to unfamiliar motion patterns commonly results in motion sickness and a false perception of motion, termed mal de debarquement, on the return to stable conditions. OBJECTIVE: To investigate whether motion sickness severity is correlated with the duration and severity of mal de debarquement; to study the possible preventive effect of projecting earth-referenced scenes (an artificial horizon) during exposure to motion on the development of mal de debarquement. METHODS: Thirty subjects were exposed to the recorded motion profile of a boat in a 3-degrees-of-freedom ship motion simulator. During the simulated voyage, the study participants were repeatedly put through a performance test battery and completed a motion sickness susceptibility questionnaire, while self-referenced and earth-referenced scenes were projected inside the simulator cabin. Six hours post disembarkation, subjects completed a questionnaire on mal de debarquement duration and severity. RESULTS: Mal de debarquement, mostly of mild severity, was reported following 59% of the exposures to the provocative motion profile, and in 79% of cases lasted less than 6 hours. The incidence of mal de debarquement, its duration, and the severity of symptoms did not differ between the various artificial horizon projection modes. Significant correlations were found between motion sickness severity and the duration and severity of the mal de debarquement that followed. CONCLUSIONS: The significant correlations found between motion sickness severity and mal de debarquement duration and severity imply that both syndromes might stem from a failure to adapt to new motion conditions. There is a disparity between the previously reported reduction in motion sickness symptoms by an artificial horizon, and its failure to influence the duration and symptoms of mal de debarquement. This might be explained by the different response in the two syndromes, physical versus cognitive.
TL;DR: Evidence is provided that yawning may be a viable behavioral marker to recognize the onset of soporific effects and their concomitant reduction in cognitive performance.
Abstract: Mild motion sickness and sopite syndrome, a symptom-complex related to motion sickness, can impact a person's ability to perform assigned tasks. However, mild motion sickness and sopite syndrome lack clear behavioral markers and are not easily identified. The objective of this study is to investigate yawning as one such behavioral marker. Thirty-nine healthy individuals participated in two 1-hour sessions and performed a multitasking battery on a head mounted display while seated on a moving platform. Yawning and motion sickness data were collected and symptoms were assessed with the Motion Sickness Assessment Questionnaire (MSAQ). Results showed that subjects who yawned while in motion had increased severity of motion sickness and symptoms of drowsiness, along with reduced cognitive performance while multitasking. The results indicate that yawning is associated with and may be a viable behavioral marker for motion sickness and sopite syndrome.
TL;DR: An experimental protocol and a statistical analysis procedure for quantitatively evaluating how motion-sickness is developed during car-driving are introduced and demonstrated that the protocol and procedure are useful for quantitative assessment of the time-course motion sickness development.
TL;DR: Galvanic vestibular stimulation has the potential of up-regulating disturbed sensory-motor mismatch originated by kinetosis and space sickness by modulating the GABA-related ion channels neural transmission in the inner ear.
Abstract: Motion sickness or kinetosis is the result of the abnormal neural output originated by visual, proprioceptive and vestibular mismatch, which reverses once the dysfunctional sensory information becomes coherent The space adaptation syndrome or space sickness relates to motion sickness; it is considered to be due to yaw, pith, and roll coordinates mismatch Several behavioural and pharmacological measures have been proposed to control these vestibular-associated movement disorders with no success Galvanic vestibular stimulation has the potential of up-regulating disturbed sensory-motor mismatch originated by kinetosis and space sickness by modulating the GABA-related ion channels neural transmission in the inner ear It improves the signal-to-noise ratio of the afferent proprioceptive volleys, which would ultimately modulate the motor output restoring the disordered gait, balance and human locomotion due to kinetosis, as well as the spatial disorientation generated by gravity transition
TL;DR: Results showed that dexamethasone lowered the motion sickness index and restored the levels of endogenous cannabinoids and the expression of the endocannabinoid CB1 receptor, which declined after the induction of motion sickness, in the dorsal vagal complex and stomach of rats exposed to a motion sickness protocol.
TL;DR: In this paper, the authors examined how the complexity of motion stimulus and the coupling of a motion stimulus to the actions of the participant influenced postural sway and motion sickness and found that postural stability is critical for our ability to engage in other behaviors and can be influenced by several factors, including changes in optic flow.
Abstract: Postural stability is critical for our ability to engage in other behaviors and can be influenced by several factors, including changes in optic flow. In situations where postural stability is degraded for prolonged periods of time, motion sickness commonly results. The current research examined how the complexity of a motion stimulus and the coupling of a motion stimulus to the actions of the participant influenced postural sway and motion sickness. Differences in incidence of motion sickness and postural sway characteristics emerged across conditions. In particular, postural sway of participants who became motion sick was characterized by increases in magnitude and spatial complexity but by a decrease in temporal complexity compared with participants who remained well.
TL;DR: The theory of heritable negative reinforcement as a basis for motion sickness is supported by extensive evidence in the medical literature and is compared and contrasted with other theories.
Abstract: It has been theorized that motion sickness evolved as a negative reinforcement system which terminates motion involving postural instability and/or sensory conflict. A hypothetical example is provided by a "thought experiment" whereby protohominids are in a tree looking for food. Selection pressure results when the organisms that have an aversion to motion-producing sensory conflict do not venture out too far on the tree limbs and therefore tend to survive. In order to support an evolutionary model for motion sickness there must be evidence for genetic and/or heritable predisposition. The present study involves a retrospective literature review which reveals abundant evidence for genetic/heritable factors in motion sickness. Examples include genetic polymorphism of the alpha-2-adrenergic receptor, which has been shown to increase susceptibility to motion sickness, examination of family trees revealing heritable motion sickness susceptibility, evidence indicating that Asians are hyper-susceptible to motion sickness, and twin studies, just to mention a few. Thus, the theory of heritable negative reinforcement as a basis for motion sickness is supported by extensive evidence in the medical literature. This theory is compared and contrasted with other theories. Further areas for research are suggested.