Knowing what's coming: Anticipatory audio cues can mitigate motion sickness.

Being able to anticipate upcoming motion is known to potentially mitigate sickness resulting from provocative motion. We investigated whether auditory cues could increase anticipation and subsequently reduce motion sickness. Participants (N = 20) were exposed on a sled on a rail track to two 15-min conditions. Both were identical in terms of motion, being composed of the same repeated 9 m fore-aft displacements, with a semi-random timing of pauses and direction. The auditory cues were either 1) informative on the timing and direction of the upcoming motion, or 2) non-informative. Illness ratings were recorded at 1-min intervals using a 11-point scale. After exposure, average illness ratings were significantly lower for the condition that contained informative auditory cues, as compared to the condition without informative cues. This knowledge, i.e. that auditory signals can improve anticipation to motion, could be of importance in reducing carsickness in domains such as that of autonomous vehicles.

Effectiveness of a placebo intervention on visually induced nausea in women - A randomized controlled pilot study.

OBJECTIVE: Improvement of nausea by placebo interventions has recently been demonstrated in clinical trials and experimental settings. However, many questions regarding placebo effects on nausea remain unanswered. For example, nausea reduction in women could only be achieved when the placebo intervention was "enhanced" by conditioning, while men responded primarily to verbally suggested improvement. It is unclear whether these findings are generalizable or were due to situational variables. In this pilot study, we investigated the effects of sham acupuncture point stimulation and verbal suggestions on visually-induced nausea in a female population. METHODS: In a within-subjects design, 21 healthy female volunteers underwent both a placebo condition and a natural history condition (control condition) in a randomized order on two separate days. On both days, nausea was induced through optokinetic stimulation. On the placebo day, participants received sham acupuncture point stimulation together with positive verbal suggestions of nausea improvement. Expected and perceived nausea severity as well as symptoms of motion sickness were repeatedly assessed. RESULTS: Twenty participants completed both testing days. Participants developed significantly less nausea on the placebo day compared to the control day (p<0.001), and the effect size of placebo-induced nausea reduction was large (partial η2=0.71). Symptoms of motion sickness were also reduced (p=0.003). Expectation of nausea decreased following the placebo intervention as compared to no treatment (p=0.030), indicating successful expectancy manipulation. CONCLUSION: Sham acupuncture point stimulation combined with verbal suggestions induced a significant placebo effect on visually-induced nausea in women.

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.

Simultaneous transcutaneous electrical nerve stimulation mitigates simulator sickness symptoms in healthy adults: a crossover study.

BACKGROUND: Flight simulators have been used to train pilots to experience and recognize spatial disorientation, a condition in which pilots incorrectly perceive the position, location, and movement of their aircrafts. However, during or after simulator training, simulator sickness (SS) may develop. Spatial disorientation and SS share common symptoms and signs and may involve a similar mechanism of dys-synchronization of neural inputs from the vestibular, visual, and proprioceptive systems. Transcutaneous electrical nerve stimulation (TENS), a maneuver used for pain control, was found to influence autonomic cardiovascular responses and enhance visuospatial abilities, postural control, and cognitive function. The purpose of present study was to investigate the protective effects of TENS on SS. METHODS: Fifteen healthy young men (age: 28.6 ± 0.9 years, height: 172.5 ± 1.4 cm, body weight: 69.3 ± 1.3 kg, body mass index: 23.4 ± 1.8 kg/m2) participated in this within-subject crossover study. SS was induced by a flight simulator. TENS treatment involved 30 minutes simultaneous electrical stimulation of the posterior neck and the right Zusanli acupoint. Each subject completed 4 sessions (control, SS, TENS, and TENS + SS) in a randomized order. Outcome indicators included SS symptom severity and cognitive function, evaluated with the Simulator Sickness Questionnaire (SSQ) and d2 test of attention, respectively. Sleepiness was rated using the Visual Analogue Scales for Sleepiness Symptoms (VAS-SS). Autonomic and stress responses were evaluated by heart rate, heart rate variability (HRV) and salivary stress biomarkers (salivary alpha-amylase activity and salivary cortisol concentration). RESULTS: Simulator exposure increased SS symptoms (SSQ and VAS-SS scores) and decreased the task response speed and concentration. The heart rate, salivary stress biomarker levels, and the sympathetic parameter of HRV increased with simulator exposure, but parasympathetic parameters decreased (p < 0.05). After TENS treatment, SS symptom severity significantly decreased and the subjects were more able to concentrate and made fewer cognitive test errors (p < 0.05). CONCLUSIONS: Sympathetic activity increased and parasympathetic activity decreased after simulator exposure. TENS was effective in reducing SS symptoms and alleviating cognitive impairment. TRIAL REGISTRATION NUMBER: Australia and New Zealand Clinical Trials Register: http://ACTRN12612001172897.

Effects of transcutaneous electrical nerve stimulation on motion sickness induced by rotary chair: a crossover study.

OBJECTIVES: Motion sickness (MS) is evoked by the conflict among somatosensory, visual, and vestibular input. Some of the MS symptoms and signs are mediated by activation of the autonomic nervous system (ANS). Transcutaneous electrical nerve stimulation (TENS), a maneuver used for pain control, was found to influence cardiovascular responses through ANS reflex, and to enhance motor function, visuospatial abilities, postural control, and cognitive function. The purpose of the present study is to investigate the effects of TENS on MS. SUBJECTS AND DESIGN: Fifteen (15) healthy young men participated in a within-subjects crossover study. Each completed four test sessions (control, rotation, TENS, TENS+rotation) in randomized order. Rotary chair (120°/s) combined with pitch movement of the subject's head was used as a model to provoke MS. Whole rotation protocol consisted of 5 1-minute rotations, each separated by a 1-minute rest period. TENS protocol involved simultaneous electrical stimulation of posterior neck and Zusanli acupoint. OUTCOME MEASURES: Motion sickness susceptibility was rated on a standardized questionnaire (Motion Sickness Susceptibility Questionnaire). Motion sickness symptoms, blood pressure (BP), skin temperature, heart rate (HR), and heart rate variability (HRV) were measured. Saliva samples were collected to analyze the level of stress markers. Cognitive function was evaluated with d2 test prior to and after MS provocation. RESULTS: Spinning by itself significantly decreased task response speed and contraction. MS symptom scores, BP, as well as the sympathetic parameter of HRV increased progressively with MS provocation (p<0.05), but skin temperature decreased (p=0.023). Severity of MS symptoms significantly decreased with TENS intervention (p<0.05). After TENS treatment, subjects were able to concentrate better and showed fewer errors in a cognitive test. Salivary cortisol concentration significant decreased after TENS treatment. CONCLUSIONS: Sympathetic activity increased but parasympathetic activity decreased during MS. TENS was effective in reducing MS symptoms as well as alleviating cognitive impairment.

Could sound be used as a strategy for reducing symptoms of perceived motion sickness?

BACKGROUND: Working while exposed to motions, physically and psychologically affects a person. Traditionally, motion sickness symptom reduction has implied use of medication, which can lead to detrimental effects on performance. Non-pharmaceutical strategies, in turn, often require cognitive and perceptual attention. Hence, for people working in high demand environments where it is impossible to reallocate focus of attention, other strategies are called upon. The aim of the study was to investigate possible impact of a mitigation strategy on perceived motion sickness and psychophysiological responses, based on an artificial sound horizon compared with a non-positioned sound source. METHODS: Twenty-three healthy subjects were seated on a motion platform in an artificial sound horizon or in non-positioned sound, in random order with one week interval between the trials. Perceived motion sickness (Mal), maximum duration of exposure (ST), skin conductance, blood volume pulse, temperature, respiration rate, eye movements and heart rate were measured continuously throughout the trials. RESULTS: Mal scores increased over time in both sound conditions, but the artificial sound horizon, applied as a mitigation strategy for perceived motion sickness, showed no significant effect on Mal scores or ST. The number of fixations increased with time in the non-positioned sound condition. Moreover, fixation time was longer in the non-positioned sound condition compared with sound horizon, indicating that the subjects used more time to fixate and, hence, assumingly made fewer saccades. CONCLUSION: A subliminally presented artificial sound horizon did not significantly affect perceived motion sickness, psychophysiological variables or the time the subjects endured the motion sickness triggering stimuli. The number of fixations and fixation times increased over time in the non-positioned sound condition.

Effects of Command and Control Vehicle (C2V) operational environment on soldier health and performance.

The purpose of this project was to use NASA technology to assist the US Army in the assessment of motion sickness incidences and effects on soldier performance and mood states within the Command and Control Vehicle (C2V). Specific objectives were (1) to determine if there was a significant difference between three internal configurations of the C2V and/or between seats within these vehicles; (2) to determine if there was a significant difference between the park, move, or short-halt field conditions; and (3) to validate a method of converging indicators developed by NASA to assess environmental impact of long duration spaceflight on crewmembers, using a large sample of subjects under ground-based operational conditions.

[An experimental validation of pharmacological agents to arrest the vestibulo-autonomic syndrome (motion sickness)]. / Eksperimental'noe obosnovanie farmakologicheskikh sredtsv kupirovaniia vestibulo-vegetativnogo sindroma (bolezn' dvizheniia).

The results of development and experimental evaluation of the efficiency of pharmacological means of cupping the vestibulo-vegetative syndrome in man are presented. A model and procedure of evaluation of pharmacological cupping of the Vestibulo-vegetative syndrome are developed. The intramuscular injection of the mixture containing ephedrine, promethazine hydrochloride and strychnine (25, 50, and 1 mg, respectively) appeared most effective.

The Canadian Forces Airsickness Rehabilitation Program, 1981-1991.

Airsickness is a significant obstacle in the training of some student pilots. When conventional therapy fails, desensitization therapy may be indicated. Using experience gained by the RAF and USAF, the Canadian Forces (CF) began such a program in 1981. This paper reports program results from 1981-1991. Following subject identification, treatment consists of three phases: biofeedback relaxation therapy, ground-based desensitization training and in-flight desensitization therapy with a pilot-flight surgeon. Employing a definition of cure used by the RAF, success was compared with that of the RAF and USAF programs. A total of 22 student pilots have undergone rehabilitation, 17 of whom have been successfully treated for a success rate of 77%. This is comparable to success rates of other programs. It is reaffirmed that desensitization is a valid clinical tool in treatment of airsickness.

Psychological differences noted in aircrewmembers undergoing systematic desensitization and their subsequent functioning.

This study presents the results of a 3-year follow-up of patients treated for flight anxiety via relaxation/desensitization. Noted differences between successfully and unsuccessfully treated patients are discussed as well as the long-range effectiveness of relaxation/desensitization. Significant differences were noted on MMPI (Minnesota Multiphase Personality Inventory) scale elevations and major presenting symptoms. There was a significant relationship between specific MMPI profiles and failure to successfully treat flight anxiety. Individuals most likely to benefit from therapy were those subjects who exhibited normal MMPI profiles and manifested airsickness as their major presenting symptom.

Self-control desensitization with cue-controlled relaxation for treatment of a conditioned vomiting response to air travel.

A 33 yr old female with a flying phobia which involved frequent conditioned vomiting and fainting was successfully treated by a combination of self-control desensitization and cue-controlled relaxation. A 12 and 18 month follow-up indicated that treatment effects were maintained. Implications are discussed of this procedure for the treatment of conditioned nausea and vomiting resulting from cancer chemotherapy.

Physiological and psychological correlates of motion sickness.

Motion sickness (MS)has been inconclusively associated with personality and physical vestibular functioning in both males and females. The present work consisted of six tests: test of field dependency; pure balance test; motion sickness questionnaire; body steadiness test; primary suggestibility test; resistance to disturbance test. In addition the EPI was completed by a proportion of subjects. Male and female data for the 15 male and 15 female subjects in an age range 20 to 30 years, obtained from within Bedford College, University of London, were factor analysed separately. The results show that, firstly, field dependence, as understood by Witkin, is not associated with any of the factor and correlated significantly (r = 0.83, P less than 0.001; two-tailed test). The same correlation in women was not significantly (r = 0.17). For females, MS and neuroticism appeared on the same factor and correlated significantly (r = 0.62, P less than 0.05; two tailed test). The same correlation in men was not significant (r = 0.06). This suggests that MS in females is associated primarily with neuroticism, whereas in males it is associated with vestibular disturbance thresholds.