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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 361 records · Page 20
All sourcesNASA NTRSDOE OSTI
NASA NTRS1974

Vestibular ataxia and its measurement in man

Methods involved in and results obtained with a new comprehensive ataxia test battery are described, and definitions of spontaneous and induced vestibular ataxia in man are given in terms of these findings. In addition, the topic of alcohol-induced ataxia in relation to labyrinth function is investigated. Items in the test battery comprise a sharpened Romberg test, in which the subject stands on the floor with eyes closed and arms folded against his chest, feet heel-to-toe, for 60 seconds; an eyes-open walking test; an eyes-open standing test; an eyes-closed standing test; an eyes-closed on-leg standing test; an eyes-closed walk a line test; an eyes-closed heel-to-toe walking test; and supplementary ataxia tests such as the classical Romberg test.

Fregly, A. R.↗
NASA NTRS1976

Research on habituation to novel visual-vestibular environments with particular reference to space flight

Progress in the development of a cohesive theory of the underlying physiological mechanisms associated with spatial orientation in unusual environments is described. Results can be applied to providing means of preventing and/or minimizing the space motion sickness which has been observed during prolonged space missions. Three major areas were investigated: (1) the interaction of visual and vestibular cues in conflict in the human, (2) the plasticity of the vestibulo-ocular reflex in monkeys, and (3) end organ function in the ray with particular emphasis on the effect of ionic concentration.

Young, L. R.↗
NASA NTRS1976

Eye movements during afterimage tracking under sinusoidal and random vestibular stimulation

The smooth portion of the horizontal vestibulo-ocular reflex was analyzed in terms of the frequency response, relating slow-phase eye velocity to angular velocity of a rotating chair under four different cases: sinusoidal rotation about a vertical axis in total darkness, sinusoidal rotation during afterimage tracking, pseudorandom head rotation in total darkness, and pseudorandom head rotation during afterimage tracking. Eye movements were recorded using a photoelectric limbus tracking method. The observation that the presence of an afterimage during vestibular stimulation increases the velocity of slow-phase eye movements is in support of the theory that such slow-phase movements are generated, at least in part, by the perceived velocity of the target. Since the target is immobilized on the retina, this perceived velocity is clearly not generated by retinal slip, but rather by a mechanism related to the eye movement such as corollary discharge.

Yasui, S.↗
NASA NTRS1977

Vestibular functions and sleep in space experiments

Physical indices of sleep were continuously monitored in an owl monkey living in a chamber continuously rotating at a constant angular velocity. The electrophysiological data obtained from chronically implanted electrodes was analyzed to determine the chronic effects of vestibular stimulation on sleep and wakefulness cycles. The interaction of linear and angular acceleration on the vestibulo-ocular reflex was investigated in three rhesus monkeys at various angular accelerations.

Perachio, A. A.↗
NASA NTRS1977

Certain aspects of the vestibular problem in space medicine

Vestibulovegetative disorders on manned space flights are discussed. A study relating to the vestibular stimuli in respiration, diaphoresis cardiac rhythm and a broad complex of hemodynamic indices was conducted. Certain tests for astronaut candidates are discussed.

Source record↗
NASA NTRS1978

Vestibular Function Research (VFR) experiment. Phase B: Design definition study

The Vestibular Functions Research (VFR) Experiment was established to investigate the neurosensory and related physiological processes believed to be associated with the space flight nausea syndrome and to develop logical means for its prediction, prevention and treatment. The VFR Project consists of ground and spaceflight experimentation using frogs as specimens. The phase B Preliminary Design Study provided for the preliminary design of the experiment hardware, preparation of performance and hardware specification and a Phase C/D development plan, establishment of STS (Space Transportation System) interfaces and mission operations, and the study of a variety of hardware, experiment and mission options. The study consist of three major tasks: (1) mission mode trade-off; (2) conceptual design; and (3) preliminary design.

Source record↗
NASA NTRS1978

Vestibular influences on other sensory and motor processes

Vestibular effects on perceptual and motor processes are widespread. It is shown that gyrovisual modulation may take three forms: (1) gyrovisual inhibition (monitoring tasks and spurious motion); (2) gyrovisual facilitation (tracking); and (3) gyrovisual conflict (motion sickness and disorientation in flight).

Clark, B.↗
NASA NTRS1979

Perception and performance in flight simulators: The contribution of vestibular, visual, and auditory information

The pilot's perception and performance in flight simulators is examined. The areas investigated include: vestibular stimulation, flight management and man cockpit information interfacing, and visual perception in flight simulation. The effects of higher levels of rotary acceleration on response time to constant acceleration, tracking performance, and thresholds for angular acceleration are examined. Areas of flight management examined are cockpit display of traffic information, work load, synthetic speech call outs during the landing phase of flight, perceptual factors in the use of a microwave landing system, automatic speech recognition, automation of aircraft operation, and total simulation of flight training.

Source record↗
NASA NTRS1980

Influence of mobility restriction on habituation of the vestibular apparatus

Test results presented indicate that 30-day hypokinesia did not affect the intensity of nystagmus: velocity of slow phase, total number of jerks, and duration of the reaction in animals were the same as before mobility restriction and did not differ from those of the control group. However, hypokinesia resulted in the disappearance of habituation of the vestibulary system to repeated angular accelerations. The known hypokinetic changes in the endocrine system were studied. It was concluded that reduction in adrenergic function may be the cause of disappearance of vestibular apparatus habituation during hypokinesia.

Gorgiladze, G. I.↗
NASA NTRS1980

Cold shivering activity after unilateral destruction of the vestibular apparatus

The bioelectric activity of muscles (flexors and extensors of the forelimbs and hindlimbs) during cold shivering after unilateral destruction of the vestibular apparatus. It was found, that unilateral delabyrinthing produces bilateral facilitation of cold shivering in the flexor extremities more pronounced on the ipsilateral side. In the extensor muscles there was an absence of bioelectric activity both before and after delabyrinthing. Enhancement of cold shivering in the flexor extremities following intervention was evidently conditioned by removal of the inhibiting effect of the vestibulary apparatus on the function of special centers.

Kuzmina, G. I.↗
NASA NTRS1980

Bioelectrical activity of limb muscles during cold shivering of stimulation of the vestibular apparatus

The effects of caloric and electric stimulation of the vestibular receptors on the EMG activity of limb muslces in anesthetized cats during cold induced shivering involved flexor muscles alone. Both types of stimulation suppressed bioelectrical activity more effectively in the ipsilateral muscles. The suppression of shivering activity seems to be due to the increased inhibitory effect of descending labyrinth pathways on the function of flexor motoneurons.

Kuzmina, G. I.↗
NASA NTRS1980

Mechanisms for vestibular disorders in space flight. Facts and hypotheses

This article discusses the vestibular disorders associated with space flight. It is found there is still no complete understanding of the changes occurring in the sensory systems of the body during weightlessness. Results of studies are presented, including results of a ground model.

Matsnev, E. I.↗
NASA NTRS1981

Habituation to novel visual vestibular environments with special reference to space flight

The etiology of space motion sickness and the underlying physiological mechanisms associated with spatial orientation in a space environment were investigated. Human psychophysical experiments were used as the basis for the research concerning the interaction of visual and vestibular cues in the development of motion sickness. Particular emphasis is placed on the conflict theory in terms of explaining these interactions. Research on the plasticity of the vestibulo-ocular reflex is discussed.

Young, L. R.↗
NASA NTRS1982

Space motion sickness and vestibular experiments in Spacelab

Approximately 43 percent of Apollo, Skylab, Soyuz/Salyut and Shuttle crewmen have experienced symptoms resembling motion sickness during their first several days in space. This paper reviews the space sickness problem in both an operational and physiological context, and describes experiments planned by a team of vestibular researchers from the USA and Canada to study space sickness and associated sensory-motor adaptation to weightlessness during Spacelab missions 1 and 4, and the German Spacelab mission D-1.

Oman, C. M.↗
NASA NTRS1983

Spatial orientation - Visual-vestibular-somatic interaction

The compensation signals from somatosensory and vestibular receptors, which act to compensate for disturbances produced by the displacement of our eyes relative to other parts of our bodies and for visual disturbances such as tilted frames or moving visual fields, are investigated. Disturbances were evoked by tilting the head and by rotating a large visual display, while compensation signals related to gravity were altered by placing the subjects horizontally on a board or seating them vertically. The first experiment studied the effects of visual disturbance on the ability of supine observers to set a line to the longitudinal body axis while the head was tilted toward one shoulder or while the head was straight. Results showed that the effects of the visual disturbance were greater when the head was tilted than when it was straight, which indicates that the effects of visual disturbance were greater for a task that required compensation. The second experiment compared the performance of supine and erect observers. No differences were found between the performance of observers on a task requiring the use of compensation signals under these two conditions, which suggests that the enrichment of compensatory signals did not reduce the effects of visual disturbancs.

Parker, D. E.↗
NASA NTRS1985

Thermoregulatory and Vestibular Systems in the Rat

Responses in six rats to auditory and vestibular stimuli were compared at two temperatures. It was observed that the peaks in the BAER recorded at a brain temperature of approximately 34 degrees centigrade occur later in time than the peaks from the 37 degree waveforms. In addition, the later peaks of the BAER recorded at the low temperature were more delayed than the earlier peaks, indicating that the interpeak latency increases as brain temperature is decreased. Responses to angular acceleration also show that later peaks in the evoked waveforms are associated with increases in interpeak latencies with decreasing temperature.

Horowitz, J. M.↗