The purpose of the present experiment was to study frequency changes in gastric myoelectric activity of healthy human subjects and the development of symptoms of motion sickness as brought about by vection or illusory self-motion. Fifteen fasted healthy human subjects were seated inside a circular vection drum, the rotation of ...

Controversy has surrounded the differentiation of Trypanosoma brucei gambiense from T. b. rhodesiense (causative agents of Gambian and Rhodesian sleeping sickness, respectively) almost from the moment they were named. In the light of recent findings from biochemical and immunological characterization studies, Wendy Gibson reviews the status of T. b. gambiense ...

The high curve speed railway vehicles (HCSRVs) of the Japanese National Railway have been operating since 1973 with the aim of increasing speed on ordinary routes with many curve track sections. Although the aim of increased speed has been attained, it has been pointed out that the swing of HCSRVs ...

Motion-induced vomiting was studied in cats exposed to vertical sinusoidal oscillation on a spring-suspended platform. Two groups of five cats each, namely, motion-untested and motion sickness-susceptible, were subjected to chronic ablation of the area postrema. Motion sickness occurred postoperatively in all the previously untested cats, and in four of the ...

A case of visually-induced motion sickness (VIMS) is presented. The patient underwent a program of dynamic adaptive vision therapy which relieved her symptoms of motion sickness. Symptoms of VIMS may include photophobia, an inability to read in a moving auto, and nausea, dizziness, headache, eye strain and anxiety following provocative ...

The aim of this research was to quantify the development of habituation or intensification of experimental motion sickness induced in Bolivian squirrel monkeys by repeated exposures to horizontal rotation. Incidence, frequency, and latency of vomiting responses were recorded from monkeys rotated daily in a transparent testing chamber at 30 rpm ...

The possible role of the alpha-2 adrenoceptors in xylazine-induced vomiting and in motion sickness was investigated. Cats were divided into two groups according to motion sickness susceptibility and were observed after s.c. injections of xylazine. The incidence of vomiting increased with the dose, and at each dose, the high susceptibility ...

Space motion sickness has become an operational concern in manned space flight. Considerable evidence exists that head movements in free fall, especially pitch movements, are provocative until adaptation occurs (3,4,8,9,11,17,18,22,26). The question arises whether space motion sickness is an unique nosological entity or is due to body movements in a ...

Episodes of emesis unaccompanied by the usual prodromal signs of motion sickness have been reported by astronauts in the space shuttle program (10). Such reports have raised the issue whether space motion sickness has different characteristics from terrestrial motion sickness. We present evidence here from parabolic flight experiments that sudden ...

Coriolis, cross-coupled angular acceleration stimulation readily induces motion sickness under terrestrial conditions. Nevertheless, the Skylab astronauts, when tested with such stimulation in-flight, were insusceptible even though each had been susceptible pre-flight. It is unclear whether this decreased susceptibility was the consequence of in-flight adaptation or in part the result of ...

Normal subjects show wide variability in their sensory scaling of breathlessness for equivalent degrees of ventilatory stimulation and behave "characteristically' irrespective of stimulus type. Observed differences are not explained by physical characteristics, ventilatory sensitivity or pattern of breathing although there is a weak association with the degree of physical fitness. ...

We have investigated Physarum polycephalum, a unicellular organism with no special gravity receptors, on its ability to react to gravity. The first experiments were 0 g-simulation experiments on the fast-rotating clinostat conducted with plasmodial strands of this acellular slime mold. In these earth-bound experiments the observed parameters were periodicity of ...

Experiments on human spatial orientation were conducted on four crewmembers of Space Shuttle Spacelab Mission 1. This introductory paper presents the conceptual background of the project, the relationship among the experiments and their relevance to a "sensory reinterpretation hypothesis". Detailed experiment procedures and results are presented in the accompanying papers ...

Eight highly-skilled hammer throwers were studied using film analysis procedures. The location and velocity of the center of mass (c.m.) of each thrower, hammer and thrower-hammer system were calculated. The vertical component of motion of all three c.m.s followed cyclic patterns with one fluctuation per turn. The fluctuation of the ...

Space sickness symptoms were observed by 4 specially trained observers on Spacelab-1. Three reported persistent symptoms, and vomited repeatedly during the first and/or second day of flight. Head movements on all axes were provocative, particularly in pitch and roll. Head acceleration data recorded from 2 symptomatic crewmen showed that after ...

Motion sickness releases ACTH, epinephrine, and norepinephrine. We are interested in endocrine responses to motion sickness, in adaptive responses leading to the resolution of the syndrome, and in how antimotion-sickness drugs influence the endocrine responses. Susceptible or insusceptible subjects were administered antimotion-sickness drugs prior to stressful stimulation. Insusceptible subjects displayed ...

The RAF Motion Sickness Desensitisation Programme has been in operation since 1966 and to January 1984 151 aircrew have been treated. The programme consists of a ground phase of treatment and a flying phase. Since January 1981 both phases have been located at Farnborough. Additional motion stimuli have been incorporated ...

Cutaneously-recorded electrogastrograms (EGGs) were obtained from 21 healthy volunteers who were seated within a drum, the rotation of which produced vection or illusory self-motion. Fourteen subjects developed symptoms of motion sickness during vection and in each the EGG frequency shifted from the normal 3 cpm to 5-8 cpm, tachygastria, an ...

During the 41-G mission, two payload specialist astronauts took part in six Canadian medical experiments designed to measure how the human nervous system adapts to weightlessness, and how this might contribute to space motion sickness. Similar tests conducted pre-flight provided base-line data, and post-flight experiments examined re-adaptation to the ground. ...

The appropriateness of kaolin consumption, one form of pica, as an index of motion sickness in the rat was examined. Unlike other motion sickness indices, the use of kaolin consumption results in a bitonic function across daily rotation sessions. This bitonic function is not predicted from any theory of motion ...

This study examined the second-order factor structure of Siller's (1969) Disability Factor Scale--General. Factor analysis of the seven attitudinal factors toward disabled individuals, based on the responses of 200 college students, yielded two major second-order factors. These two second-order factors of Net Affect and Authoritarian Virtuousness are further discussed in ...

We evaluated Transdermal Scopolamine related to the time of application prior to the onset of motion. In this study 44 subjects participated. The first group applied the transdermal disc within 4 h and the second group 8 h or more prior to the onset of motion. We observed a significant ...

The current status and implications of the neurohumoral hypothesis of motion-induced vomiting are reviewed. Data show that squirrel monkey subjects vomit only once if horizontal rotation is terminated immediately on the occurrence of the emetic response. Refractory periods for multiple vomiting episodes concurrent with continued rotation are sufficiently brief to ...

A motion sickness device is described which produces motion sickness in about 40% of an unselected population of unrestrained female cats during a 30-min exposure at 0.28 Hz. The apparatus provides a gentle wave stimulus, similar to that provided by an amusement park Ferris Wheel. Two cats may be tested ...

The emetic chemoreceptor trigger zone (CTZ), located in the area postrema of the medulla oblongata, is generally believed to be indispensable for the vomiting in motion sickness and, by extrapolation, also in space sickness. Accordingly, it has been postulated that a "motion vomiting substance" is secreted into the cerebrospinal fluid ...

Twenty-eight chronic headache sufferers of three headache types (migraine, tension and combined migraine-tension) selected on the basis of explicit inclusion and exclusion criteria and matched on five demographic characteristics were assessed in a headache and non-headache state on a number of psychophysiological measures (frontalis, forearm and neck EMG; cephalic vasomotor ...

It has recently been demonstrated that bubble formation in the crab Pachygrapsus crassipes is induced by limb motions following decompression from nitrogen pressures as low as 2 atm. Preformed gaseous nuclei are not involved in this process and are absent from this animal. We further demonstrate here that nuclei do ...

Under a variety of experimental conditions, nonrestrained adult male squirrel monkeys were subjected to continuous rotation in the horizontal plane at 33 rpm. Severity of motion-induced sickness was quantified by measuring latencies of three responses associated with sickness. Per- and postrotational nystagmus was recorded from a subsample of monkeys with ...

Space motion sickness (SMS) is an important medical problem facing NASA's space shuttle program. Two theories that have been advanced to explain SMS are the "fluid shift theory" and the "vestibulo-ocular sensory conflict theory". The "fluid shift theory" pre-supposes an active or passive shift of body fluid to the central ...

In studying physiologic responses to behavioral stressors, there are two competing strategies. Laboratory studies offer greater experimental control but less provocation. Field studies provide poorer experimental control but potentially greater provocation. Despite these differences, comparison within subjects of neuroendocrine responses to these different settings has not been performed. We studied ...

Membrane potential responses of a Hodgkin-Huxley oscillator to an externally-applied sinusoidal current were numerically calculated with relation to bifurcation parameters of the amplitude and the frequency of the stimulating current. The Hodgkin-Huxley oscillator, or the Hodgkin-Huxley axon in the state of self-sustained oscillation of action potentials, was realized by immersing ...

Unusual vestibular responses to head movements in weightlessness may produce spatial orientation illusions and symptoms of space motion sickness. An integrated set of experiments was performed during Spacelab 1, as well as before and after the flight, to evaluate responses mediated by the otolith organs and semicircular canals. A variety ...

Motion sickness affects approximately 90 percent of the population at some time during life, and for many the problem is recurrent and severe. Labyrinthine-defective individuals are "immune." Adaptation is highly specific to one type of motion. Recent studies have focused on the role of the limbic system in mechanisms of ...

The two main principles of ergonomics can be said to 'fit the job to the man', or 'fit the man to the job'. To a high extent this is really valid for lighting ergonomics. If an employee complains that he (or she) cannot see properly what he is doing in ...

The effect of transdermally administered scopolamine (TTS scopolamine) (release rate 5 micrograms/h) and dimenhydrinate (100 mg) was examined on optovestibular nystagmus in 16 volunteers in a randomized double-blind trial. A statistically significant decrease in the optokinetic part of nystagmus was observed during all treatments. Most profound reduction was found during ...

Every individual exhibits unique perceptual, behavioral, and physiological responses within and across a variety of settings. Despite the idiosyncratic nature of responses, we seek to establish theories that generalize across a large number of individuals. A strict idiographic method intensively examines the response patterns of a small number of individuals, ...

We compared susceptibility to motion sickness during exposure to sudden-stop stimulation as a function of gravitoinertial force level. Our findings show that susceptibility is greatly enhanced, both with eyes-closed and eyes-open, for zero-g and 2-g conditions in parabolic flight compared with 1-g test conditions. The change in susceptibility is likely ...

This paper addresses the "fluid shift theory" of space motion sickness. The primary purpose of our research was the development of procedures to assess individual differences in response to rostral body fluid shifts on earth. Experiment I examined inner ear fluid pressure changes during head-down tilt in intact human beings. ...

A sharp distinction should be made between symptoms of motion-sickness per se and phenomena inferred from the symptomatology, which include rates of acquisition and decay of adaptation effects. Foreknowledge of these "derived phenomena" are valuable if it can be shown that they hold true for virtually any motion environment. Recently, ...

If a foot were surgically removed and it was observed that walking was then impaired, it could be concluded that the foot is part of the normal mechanism for walking and that one of the physiological functions of the foot is to facilitate walking. In seven dogs, the vestibular apparatus ...

Motion sickness occurs in a wide variety of circumstances involving real or apparent motion, many of them novel and man-made. Significantly, voluntary body movements rarely result in symptoms, and the likelihood of motion sickness is greatly reduced by having control of the vehicle in which one is riding. The unifying ...

The evidence for possible roles of catecholamines in motion sickness is reviewed. l-Dopa is implicated in that it is the precursor to catecholaminergic neurotransmitters. Dopamine may have a role in stimulating motion sickness, though much basic information is lacking. Epinephrine may have a stimulatory role, since anatomical, pharmacological and physiological ...

The role of vision in motion sickness has often been either exaggerated or ignored. After examining some early theories of motion sickness, this review discusses the sensory conflict theory and visual aspects of motion sickness. A wide range of preventative measures, both optometric and non-optometric, are presented to give the ...

Space sickness is generally considered a variant of motion sickness although not fully proved as such. Understanding space sickness requires objective and quantitative characterization of the disorder. Vomiting is a quantifiable physiological event performed by the respiratory muscles which generate the pressures that evacuate the gut. Vomiting from all causes ...

The possibility that there might be a neurohumoral cerebrospinal fluid (CSF) link in motion sickness was directly tested in cats by blocking the flow of CSF from the third into the fourth ventricle. Evidence obtained thus far is consistent with the hypothesis. Cats with demonstrably sound blocks did not vomit ...

Eight subjects, wearing left-right vision reversing goggles, executed sequences of controlled active head movements to provoke motion sickness. Head movement sequences were interspaced with periods of eye closure and no head movement to permit partial remission of symptoms between sequences. Subjects reported the level of discomfort experienced by using a ...

Space motion sickness has been estimated as affecting between 1/3 and 1/2 of all space flight participants. NASA has at the moment proposed a combination of promethazine and ephedrine (P/E) and one of scopolamine and dextroamphetamine (S/D), both given orally, as well as a transdermally applied scopolamine (TAS), as preventive ...

Visual search within a head-fixed display consisting of a 12 X 12 digit matrix is degraded by whole-body angular oscillation at 0.02 Hz (+/- 155 degrees/s peak velocity), and signs and symptoms of motion sickness are prominent in a number of individuals within a 5-min exposure. Exposure to 2.5 Hz ...

Independent groups of up to 32 young men exposed in a standard seated posture to one of five conditions of vertical (Z axis) motion for up to 2 h. Exposure was less in the event of vomiting or a volunteer's voluntary withdrawal from the experiment. A control condition, sinusoidal motion ...

The existing literature dealing with the phasic orienting response (OR) in schizophrenia, examining, for the most part, the skin conductance component (SCOR), reports conflicting results with divergent implications for the nature of the attentional dysfunction in these patients. The present authors have contributed to that literature and to its divergencies. ...