Nineteen normal persons and three deaf subjects with bilateral loss of labyrinthine function (L-D subjects) were exposed to Coriolis accelerations during the brief periods of weightlessness in parabolic flighy by having them move their heads while rotating in a Barany chair at 30 rpm. None of the L-D but all of the normal subjects except three experienced motion sickness: Only one of eight subjects selected on the basis of insusceptibility to symptoms in standard parabolic flights was free of symptoms; the other seven were motion sick and completed on the average only six parabolas. Two of three subjects selected primarily on the basis of low susceptibility to Coriolis acceleration in a slow rotation room were symptom free, and one was motion sick but his level of symptoms did not reach the end point of severe malaise during ten parabolas. In addition to demonstrating susceptibility to motion sickness when exposed to Coriolis acceleration in the weightless phase of parabolic flight, the findings are important in emphasizing the difficulty in predicting susceptibility to motion sickness in novel force environments. (Author).

Nineteen normal persons and three deaf subjects with bilateral loss of labyrinthine function (L-D subjects) were exposed to Coriolis accelerations during the brief periods of weightlessness in parabolic flighy by having them move their heads while rotating in a Barany chair at 30 rpm. None of the L-D but all of the normal subjects except three experienced motion sickness: Only one of eight subjects selected on the basis of insusceptibility to symptoms in standard parabolic flights was free of symptoms; the other seven were motion sick and completed on the average only six parabolas. Two of three subjects selected primarily on the basis of low susceptibility to Coriolis acceleration in a slow rotation room were symptom free, and one was motion sick but his level of symptoms did not reach the end point of severe malaise during ten parabolas. In addition to demonstrating susceptibility to motion sickness when exposed to Coriolis acceleration in the weightless phase of parabolic flight, the findings are important in emphasizing the difficulty in predicting susceptibility to motion sickness in novel force environments. (Author).

Motion sickness susceptibility of five labyrinthine-defective (L-D) and 25 normal subjects was tested under the force environments encountered in parabolic flight (0 g and hyper-g). The L-D subjects were uniformly symptomless, while the normal subjects revealed great inter- and intra-individual differences in susceptibility to motion sickness provoked by standardized head movements during: (1) the hypergravic and (2) the weightless phases of the parabolic maneuver while restrained; and (3) the weightless phase while being rotated in a chair. Four of six subjects tested under condition 1 were completely unaffected by the condition while two reacted with symptoms. Condition 2 provoked severe symptoms in five of the twelve subjects tested and moderate symptoms in one. Fifteen subjects tested under condition 3 revealed either a marked increase or decrease in susceptibility to Coriolis acceleration in weightlessness compared to terrestrial baseline measurements. (Author).

Motion sickness susceptibility of five labyrinthine-defective (L-D) and 25 normal subjects was tested under the force environments encountered in parabolic flight (0 g and hyper-g). The L-D subjects were uniformly symptomless, while the normal subjects revealed great inter- and intra-individual differences in susceptibility to motion sickness provoked by standardized head movements during: (1) the hypergravic and (2) the weightless phases of the parabolic maneuver while restrained; and (3) the weightless phase while being rotated in a chair. Four of six subjects tested under condition 1 were completely unaffected by the condition while two reacted with symptoms. Condition 2 provoked severe symptoms in five of the twelve subjects tested and moderate symptoms in one. Fifteen subjects tested under condition 3 revealed either a marked increase or decrease in susceptibility to Coriolis acceleration in weightlessness compared to terrestrial baseline measurements. (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.

A selection of annotated references to unclassified reports and journal articles that were introduced into the NASA scientific and technical information system and announced in Scientific and technical aerospace reports (STAR) and International aerospace abstracts (IAA).