Motion sickness is a completely artificial disease which has plagued mankind since we first stepped onto a floating raft or climbed onto an animal's back. Characterized by symptoms of nausea, emesis, pallor, vertigo, sweating, and general malaise, motion sickness is not only debilitating, but in the case of military fighter pilots or astronauts in space, these symptoms can be lethal. Typically, motion sickness is treated with medications such as scopolamine or promethazine. While these medications may be highly effective, they produce unwanted sideeffects such as blurred vision, slower reaction time, decreased short-term memory, and impairment of decision making skills. As such, American military pilots under the influence of such medications are not allowed to fly solo.  

Most research in this field has been devoted to the study of vestibular physiology, perceptual phenomena, or pharmacological intervention in man and in animals. In contrast, the primary objective of our own research group has been to develop a method of training people to control their own motion sickness symptoms. Our method of treatment is AutogenicFeedback Training (AFT), which involves training physiological self-regulation.

Because our laboratory research showed that certain Autonomic Nervous System (ANS) responses were correlated with, and were indeed predictors of reports of motion sickness distress (i.e., consistently preceded), it was hypothesized that training subjects to control these responses might prevent or reduce symptoms. The observed individual differences in responding suggest that, to be effective, such training would have to be directed at the different responses for different people. In other words, training would have to be "tailored" for each individual.

AFT is actually a combined application of several physiological and perceptual training techniques, principal among these are Autogenic Therapy and biofeedback. This combined therapies approach produces a methodology which is appreciably more effective than either of these two techniques when used alone. Autogenic exercises provide the subject with a specific set of instructions and method of concentration which are likely to produce the desired response. For example, self-suggestions of warmth in the hands and feet are associated with measurable increases in peripheral vasodilatation. Consequently, the time normally spent by the subject using a trial and error strategy is shortened and the initial probability of making a correct response is substantially increased. Biofeedback complements Autogenic Therapy by providing immediate sensory information to the subject about the magnitude and direction of a response. Operant conditioning procedures allow for more precise control of a response, and the "reward" (or feedback) can be presented only as the subject makes gradually larger response changes in the desired direction. As a result, the ultimate effectiveness of training is significantly increased.

During a typical training session, subjects are instructed to control a pattern of 12 to 20 different physiological responses and are given many different feedback displays (visual and auditory) simultaneously. Multiparameter feedback requires additional training in attending to a complex set of feedback signals. Verbal instructions by the experimenter are often required to direct the subject's attention to specific feedback signals and to advise him of alternative strategies when an inappropriate response has occurred. Included in these alternative strategies are elements.of systematic desensitization and progressive relaxation of muscle tension monitored at several sites.

In preparation for tests of AFT in space, we conducted investigations on over 300 people. Each study was designed to test the effectiveness of AFT as a countermeasure for motion sickness, and the feasibility of using AFT to prevent or reduce the severity of space motion sickness symptoms in aerospace crews. Another important objective was to determine if the reduction in symptoms observed could be attributed to some experimental factor other than AFT.

Research showed that the reduction in symptoms was clearly due to the degree of autonomic control demonstrated during AFT. Other results showed that tolerance to motion sickness increased only in the group that received AFT, and that these effects were still present three years after this treatment ended.This effect was achieved with 6 hours of training and both sexes learned to increase their tolerance equally. People who were highly susceptible to motion sickness could learn to suppress these symptoms just as well as those with more resistance to motion sickness. AFT has an advantage over the training methods for motion sickness because it enables trained persons to simultaneously regulate their levels of many physiological variables. This results in a more system wide reactivity to stressors and this makes the person a more capable pilot in other circumstances as well.

AFT, as described in this paper, was developed for use in the NASA space program as an alternative to traditional chemotherapy treatment for space motion sickness, and has been tested successfully aboard two shuttle missions. A number of `space medicine spin-off applications for AFT in finding solutions to Earth-based problems have been and continue to be explored. Included among these are tests of AFT for training cancer patients to suppress the nausea associated with radiation or chemotherapy; improvements in the effectiveness of the treatment of essential orthostatic intolerance (e.g., as in paralyzed patients); the successful treatment of military pilots suffering from intractable airsickness, for whom all other forms of treatment had failed. And most recently, a demonstration that AFT significantly improves pilot performance during emergency flying conditions in a number of areas including: crew coordination and communication, planning and situational awareness, stress management, and aircraft handling. It was concluded that the pilot performance improvements observed were due to learned self-regulation of autonomic responses to environmental stressors. These findings may be instrumental in reducing stress-related performance decrements associated with `human error' fatal aircraft accidents.

Cowings, P.S., Naifeh, K.H., Toscano, W.B. The stability of individual patterns of autonomic responses to motion sickness simulation. Aviation, Space and Environmental Medicine, 1990; 61:(5), 399-405.

© 1995
Association for Applied Psychophysiology and Biofeedback