Adaptation To Coriolis Accelerations

The problem was to determine how adaptation to Coriolis accelerations, acquired through controlled head movements in a room rotating in one direction, transfers to the opposite direction as a consequence of the stimulus mode during an intervening period at zero velocity. Under one experimental condition the subjects continued to make the same head movements as those used to acquire perrotational adaptation, thus evoking postrotational responses opposite in sign but similar in quality to those experienced during the initial period of rotation. In the other, mechanical restraints were applied to the head and torso for an equivalent period of time. Subjects who performed the head motion activity during the intervening static period were able to adapt more rapidly to the second (opposite) direction of rotation than to the first. In addition, the intervening activity appeared to confer some immunity to motion sickness during the second direction of rotation. Postrotational effects following the second direction of rotation were less severe and of shorter duration than those experienced following the initial period of rotation. The opposite findings were obtained for those subjects who remained immobilized during the intervening period at zero velocity. (Author).

The purpose of this experiment was to answer specific questions relating to the design of an adaptation schedule effective in protecting against motion sickness in a rotating environment. Ten men with normal vestibular function executed controlled head and body movements at each of ten 1-rpm step increase in the velocity of the Pensacola Slow Rotation Room. On the completion of every moment, subjects were required to indicate whether or not they had detected sensations of vestibular or somatosensory origin. At each velocity step, the movements were continued until each of 24 consecutive movements had elicited a negative response and the subject was judged to be symptom free. When this arbitrary adaptation criterion was reached, the angular velocity was increased by 1 rpm and the procedure repeated. On attaining the criterion at the terminal velocity (10 rpm), the rotation was stopped and the postrotatory phenomena were investigated using the same techniques. The principal finding was that the number of movements necessary to achieve the adaptation criterion was systematically related to the absolute level of angular velocity. Considerably more head and body movements were required to reach the same level of adaptation at faster speeds than at slower speeds, even though the size of the step increment remained constant. There was some evidence to indicate that the amount of stimulation to criterion depended upon the initial magnitude of sensation elicited by the increment. There were also wide individual differences in both the rate of adaptation and the minimum velocity necessary to evoke sensation. (Author).

This compendium, written by active researchers in the field, encompasses topics ranging from anatomical and physiological subjects, through analyses of stimulus characteristics, prediction of sickness, and consideration of human factors, to pharmacological and behavioral therapeutic measures for terrestrial as well as microgravity travelers. Material often found scattered in diverse journals, paper-bound proceedings of symposia, difficult-to-find laboratory reports, or included with other topics in collections having a diffuse focus, are presented here in one volume dedicated to a single theme. The critical up-to-date- reviews are a first source for researchers and research program managers as well as an essential information source for engineers and practitioners.

The function of the vestibular system is not as obvious as those of vision, hearing, touch or smell. Vestibular dysfunction, however, is clearly apparent where lesions are present. It is probably for this reason that the vestibular sense was not discovered until the nineteenth century and that clinicians have continued to playa major role in basic vestibular research right up to the present. The relationship between basic and clinical research is certainly stronger in the vesti bular field than in that of tactile sensation, for instance, as testified by the work of clinicians as MENIERE, BREUER, BARANY, DEKLEIJN and FRENZEL. In this respect the situation is similar in vestibular physiology and in endocrinology, and for the same reason. This second part of the vestibular volume of the Handbook of Sensory Physio logy will be of interest to neurologists, otologists, neurosurgeons, ophthalmologists and physiotherapists on the one hand, and psychologists, physiologists, engineers and aviation specialists on the other. For a full understanding of Part 2, it is necessary to have assimilated the basic anatomy, physiology, and biochemistry of Part 1.

This book offers a survey of the state of the art in the field of motion sickness. It begins by describing the historical background and the current definition of motion sickness, then discusses the prevalence among individuals, along with the physiological and psychological concomitants of the disorder. It reviews the incidence of motion sickness in numerous provocative motion environments and discusses various personal factors that appear to influence this aspect. Various characteristics of provocative motion stimuli are also described, together with the results of studies conducted in the laboratory, on motion simulators and at sea. Laboratory tests that could potentially be used to assess an individual’s susceptibility to motion sickness and his or her ability to adapt to motion environments are presented in detail, together with the ways in which individuals might be trained to prevent motion sickness or more effectively cope with motion environments. In closing, the book reports on the cognitive-behavioral approach developed by the author (Dobie, 1963) as well as the various desensitization programs employed in military settings, and discusses the relative effectiveness of these methods in comparison to cognitive-behavioral counseling.

II. Sensation, Perception & Attention: John Serences (Volume Editor) (Topics covered include taste; visual object recognition; touch; depth perception; motor control; perceptual learning; the interface theory of perception; vestibular, proprioceptive, and haptic contributions to spatial orientation; olfaction; audition; time perception; attention; perception and interactive technology; music perception; multisensory integration; motion perception; vision; perceptual rhythms; perceptual organization; color vision; perception for action; visual search; visual cognition/working memory.)