Real-time motion sickness measurement: Feasibility and application of the real-time motion sickness scale (RMS).

Electric vehicles (EVs) pose a heightened risk of inducing motion sickness in passengers compared to conventional internal combustion engine vehicles. With the increasing prevalence of EVs, there is a pressing need for in-depth research on motion sickness in this specific context. To quantitatively assess motion sickness severity in electric vehicle occupants, this study meticulously selected 25 participants exhibiting a high susceptibility to motion sickness for experimental testing. The research endeavors to elucidate the intricate relationship between motion sickness assessment values, electrodermal activity (EDA) signals, and vehicle state signals during motion sickness episodes. Utilizing correlation analysis to scrutinize the interrelation between electrodermal signals and the severity of motion sickness, we advocate employing the mean and variation rate of EDA as objective metrics for characterizing the extent of motion sickness. Furthermore, we introduce the definition of cumulative seat rail vibration acceleration (CVA) as an integral component of this evaluation. Through meticulous correlation analysis, it is ascertained that the change rates of longitudinal vibration cumulative value (CVAx) and EDA exhibit robust correlations, signifying their significance in relation to motion sickness severity. This research not only establishes a theoretical foundation for quantifying motion sickness in electric vehicle occupants but also contributes profound insights into the underlying mechanisms of motion sickness in the context of electric vehicles.

Motion sickness is a common issue in electric vehicles, significantly impacting passenger comfort. This study aims to develop a functional brain network analysis model by integrating electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS) signals to evaluate motion sickness symptoms. During real-world testing with the Feifan F7 series of new energy-electric vehicles from SAIC Motor Corp, data were collected from 32 participants. The EEG signals were divided into four frequency bands: delta-range, theta-range, alpha-range, and beta-range, and brain oxygenation variation was calculated from the fNIRS signals. Functional connectivity between brain regions was measured to construct functional brain network models for motion sickness analysis. A motion sickness detection model was developed using a graph convolutional network (GCN) to integrate EEG and fNIRS data. Our results show significant differences in brain functional connectivity between participants in motion and non-motion sickness states. The model that combined fNIRS data with high-frequency EEG signals achieved the best performance, improving the F1 score by 11.4% compared to using EEG data alone and by 8.2% compared to using fNIRS data alone. These results highlight the effectiveness of integrating EEG and fNIRS signals using GCN for motion sickness detection. They demonstrate the model’s superiority over single-modality approaches, showcasing its potential for real-world applications in electric vehicles.

Motion and space sickness: Intestinal and autonomic correlates

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. 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. 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. 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. 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. 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). 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.

Antihistamines for motion sickness.

Electric vehicles (EVs), though becoming increasingly popular, raise concerns about motion sickness (MS). However, few studies have explored the causes of and solutions to MS in EVs. The regenerative braking (RB), as a unique function in EVs, is believed to cause MS but has not been validated. Thus, we investigated the effect of RB on MS development and explored whether providing auditory motion cues can mitigate MS among passengers. An on-road study with 16 participants who are susceptible to MS was conducted, with the level of RB (low- versus high-level) and auditory motion cues (presence versus absence) as the within-subject factor. Our results confirmed that higher levels of RB can induce MS. Further, providing auditory motion cues can mitigate MS when high-level RB was used. The findings highlight the importance of motion cues in EVs and provide insights into the design of RB systems and corresponding human-machine interaction strategies.

The objective of the study is to show that trait anxiety and motion sickness history are responsible for different temporal progressions of sickness in passengers. The level of inflight anxiety and inflight sickness severity was monitored for 124 passengers in a full-motion cabin simulator during a short-haul flight with four different flight segments. Four groups with different characteristics in trait anxiety and motion sickness susceptibility showed different profiles of inflight sickness development. High trait anxiety was responsible for high inflight anxiety and a constantly high level of motion sickness, while passengers with just a motion sickness history showed an increase in motion sickness severity over time. We suggest that trait anxiety and motion sickness susceptibility interact and have an impact on the temporal progression of inflight sickness severity. The analysis of temporal developments of anxiety and sickness are fruitful for understanding the origins of motion sickness, research and individual treatments. Practitioner summary: In a full-motion cabin simulator study with 124 passengers the level of inflight anxiety and inflight sickness severity was monitored. Trait anxiety and motion sickness history were found to have different impacts on the temporal progression of individual sickness severity. Abbreviations: ANOVA: analysis of variance; AVES: air vehicle simulator; hiA/hiM: group with high anxiety and high motion sickness susceptibility; hiA/loM: group with high anxiety and low motion sickness susceptibility;MSSQ: motion sickness susceptibility scale; loA/hiM: group with low anxiety and high motion sickness susceptibility; loA/loM: group with low anxiety and low motion sickness susceptibility; SPSS: statistical package for the social sciences; SSQ-TS: total score from the simulator sickness questionaire; STAI: state trait anxiety inventory

Can acceleration-coded vibrations help alleviate passenger motion sickness? Investigation in stop-and-go passenger rides.

This study investigates the influence of different variations of active roll stabilization (curve tilting, roll compensation and passive) and rear wheel steering (with and without) on the severity of motion sickness (MS) symptoms experienced by vehicle occupants, as there is a hint for reduction of MS based on past studies. A simulator study with 50 participants (age 20-60, 50% women, 50% men) was conducted. The simulator used features eight DOF and is able to reproduce the maneuvers realistically, which is necessary to reduce the probability of cross couplings with simulator sickness. There were two scenarios: driving on a winding country road and highway driving with frequent lane changes. MS severity was measured subjectively via questionnaire and objectively via heartrate. In addition temperature data was collected. Even though MS symptoms have been evoked, no significant effects were found in case of suspension settings for MS in general. For single symptoms nausea and vertigo, slight significances were detected between the roll compensated car and the other variants. High lateral acceleration led to significantly higher motion sickness ratings for all suspension variants and should be avoided in trajectory planning for autonomous vehicles. In conclusion there is no benefit by the use of active roll stabilization and rear wheel steering systems in case of motion sickness, when driving in similar driving conditions as in this study. But there is also no negative effect and there is some evidence, that another kind of control algorithm may have a positive effect.

Virtual vehicles (e.g., driving video games) can give rise to visually induced motion sickness. Typically, people drive virtual vehicles. In the present study, we investigated motion sickness among participants who were exposed to virtual vehicles as passengers; that is, they observed vehicle motion, but did not control it. We also asked how motion sickness and the postural precursors of motion sickness might be influenced by participants' previous experience of driving physical vehicles. Participants viewed a recording of a virtual automobile in a driving video game. Drivers were young adults with several years of experience driving physical automobiles, while non-drivers were individuals in the same age group who did not have a driver's license and had never driven an automobile. During exposure to the virtual vehicle, we monitored movement of the head and torso. The independent measures included the incidence and severity of motion sickness. After exposure to the virtual vehicle, the incidence and severity of motion sickness did not differ between Drivers and Non-Drivers. By contrast, postural movement differed between participants who later became motion sick and those who did not. In addition, during exposure to the virtual vehicle, physical driving experience was related to patterns of postural activity that preceded motion sickness. The results are consistent with the postural instability theory of motion sickness, and illuminate relations between the control of physical and virtual vehicles.

The vestibulo-ocular reflex (VOR) is the reflexive eye movement occurring in the opposite direction of head movement to stabilize the visual image during head movement. We hypothesize that there exists a correlation between motion sickness and the accuracy of VOR because motion sickness and VOR are thought to be related to the head movement signals estimated in the central nervous system. The first purpose of the present research is to investigate the relationship between motion sickness and VOR accuracy using a mathematical model, which simultaneously describes motion sickness and VOR. The result of numerical simulation experiments shows a strong negative correlation between VOR accuracy and the severity of motion sickness. The second purpose is to investigate the relationship between motion sickness and VOR accuracy by experiments on humans. The result shows moderate negative correlations between the VOR accuracy and the severity of motion sickness among participants.

We asked whether body sway during performance of a visual-manual task would differ between boxers who experienced post-match motion sickness and those who did not. Before and after boxing we measured standing body sway while participants performed a manual precision aiming task. After boxing, participants stated, yes/no, whether they were motion sick; they also reported motion sickness symptoms, and concussion-related symptoms. Seven of thirteen boxers reported motion sickness after boxing. We compared boxers who reported post-boxing motion sickness versus those who did not. Body sway before boxing differed between boxers who reported post-bout motion sickness and those who did not. Immediately after boxing, motion sickness symptoms and concussion-related symptoms were elevated among boxers who stated that they were motion sick. The results suggest that patterns of body sway may be related to individual differences in susceptibility to motion sickness and concussion-like symptoms in adult male boxers, such that objective measurements of body sway might be used to predict susceptibility in individuals.

Individuals who experience motion sickness (MS) frequently mention the presence of smells in the environment as a factor favoring the occurrence of MS symptoms. The aim of the present work was to compare olfactory function in MS sensitive (MS+) and insensitive (MS-) subjects. Olfactory testing included determination of odor detection thresholds, subjective evaluation of the quality (intensity, hedonicity, and familiarity) of three different odorants (limonene, isovaleric acid, and petrol) as well as measures of skin conductance responses to these three odorants. Results showed no difference in olfactory sensitivity between MS+ and MS- subjects. However, findings of both subjective (odor quality self-rating) and objective (psychophysiological responses) measures did reveal that the affective response to petrol odor was significantly different in MS+ and in MS- subjects. Indeed, on a scale from 0 (unpleasant) to 10 (pleasant) MS+ subjects rated petrol odor as more unpleasant (mean = 2.52) than MS- subjects (mean = 4.15) and rise-time of skin conductance responses to petrol odor was significantly longer in MS+ (mean = 5.98 s) compared to MS- subjects (mean = 3.22 s). Our study delves further into the knowledge of the relationship between motion sickness and olfaction by demonstrating a modified olfactory perception in motion sickness sensitive subjects at both the psychophysical and psychophysiological levels.Jacquot L, Millot J-L, Paillard AC. Assessment of olfactory perception in individuals with motion sickness. Aerosp Med Hum Perform. 2018; 89(5):428-433.

The study aimed was to determine whether there was a gender difference in sensitivity to visual stimulation-induced motion sickness (MS). Forty-nine participants (Female: 24, Male: 25) volunteered to join in the study. Participants were exposed to a visual video-recording stimulus to evoke the MS. Simulator Sickness Questionnaire (SSQ) was administered before, after, and 30 min after the MS stimulation to determine MS symptoms. Participants' self-report was used to identify motion sickness. Postural sway (PS) was measured before and immediately after MS stimulation. 58.3% of the female and 48.0% of the male reported that they had MS, while 41.7% of the female and 52.0% of the male reported that they did not have MS. Gender and MS distributions were not significant (p=0.469). Participants with MS before the stimulation had higher PS than those who declared no MS (p=0.008), but PS was not different after the stimulation (p=0.102). Although there was no difference in the pre-test (p=0.231), men with MS had higher PS than women with MS at the post-test (p=0.013). There was a significant increase in PS of men who declared that they had MS after the stimulation (p=0.012). The pre-test (p=0.899) and post-test (p=0.434) SSQ scores of men and women with MS were not different, while women had higher SSQ scores than men at the post-test 30 (p=0.020). Finally, there was no correlation between gender and rates of MS. In terms of symptom severity, females appear to be more susceptible to MS. PS may be a precursor to MS.

Tilting the head in roll to or from the upright while rotating at a constant velocity (roll while rotating, RWR) alters the position of the semicircular canals relative to the axis of rotation. This produces vertical and horizontal nystagmus, disorientation, vertigo, and nausea. With recurrent exposure, subjects habituate and can make more head movements before experiencing overpowering motion sickness. We questioned whether promethazine lessened the vertigo or delayed the habituation, whether habituation of the vertigo was related to the central vestibular time constant, i.e., to the time constant of velocity storage, and whether the severity of the motion sickness was related to deviation of the axis of eye velocity from gravity. Sixteen subjects received promethazine and placebo in a double-blind, crossover study in two consecutive 4-day test series 1 month apart, termed series I and II. Horizontal and vertical eye movements were recorded with video-oculography while subjects performed roll head movements of approx. 45 degrees over 2 s to and from the upright position while being rotated at 138 degrees /s around a vertical axis. Motion sickness was scaled from 1 (no sickness) to an endpoint of 20, at which time the subject was too sick to continue or was about to vomit. Habituation was determined by the number of head movements that subjects made before reaching the maximum motion sickness score of 20. Head movements increased steadily in each session with repeated testing, and there was no difference between the number of head movements made by the promethazine and placebo groups. Horizontal and vertical angular vestibulo-ocular reflex (aVOR) time constants declined in each test, with the declines being closely correlated to the increase in the number of head movements. The strength of vertiginous sensation was associated with the amount of deviation of the axis of eye velocity from gravity; the larger the deviation of the eye velocity axis from gravity, the more severe the motion sickness. Thus, promethazine neither reduced the nausea associated with RWR, nor retarded or hastened habituation. The inverse relationship between the aVOR time constants and number of head movements to motion sickness, and the association of the severity of motion sickness with the extent, strength, and time of deviation of eye velocity from gravity supports the postulate that the spatiotemporal properties of velocity storage, which are processed between the nodulus and uvula of the vestibulocerebellum and the vestibular nuclei, are likely to represent the source of the conflict responsible for producing motion sickness.