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Ultrastructure of otolith organs in squirrel monkeys in different postures after exposure to high levels of gravitoinertial force
Gemini 5 and 7 astronaut participation in otolith function experiments
Influence of otolith organs on visual horizontal perception
Oculogravic illusion as indicator of otolith function based on specific testing conditions
Fast tilt test of semicircular canals in cats, and slow tilt and dropping platform tests of otoliths in cats
Control theory applied to analysis of vestibular function for obtaining mathematical model of semicircular canals and otolith organs
Chemical analysis of molecular structure and chemical composition of fish otoliths
Cosmonauts inversion illusion in parabolic flight studied with normal and deaf subjects, noting probable dependence on otolith function
Dynamic otolith model based on input-output experiments, including static component to permit steady output to acceleration or sustained tilt
Evaluation of otolith organ function by photographic measurement of ocular counterrolling
Otolith stimulation effects on nystagmic and sensory human reactions during acceleration
Otolith organs as primary etiological factor in motion sickness
Scheduled double launch of Orbiting Frog Otolith and Radiation Meteor spacecraft by single Scout launch vehicle - press kit
Ocular counter-rolling as otolith organ function indicator
Human subjects were exposed to a linear acceleration vector that rotated in the transverse plane of the skull without angular counterrotation. Lateral eye movements showed a sinusoidal change in slow phase velocity and an asymmetry or bias in the same direction as vector rotation. A model is developed that attributes the oculomotor response to otolithic mechanisms. It is suggested that the bias component is the manifestation of torsion of the statoconial plaque relative to the base of the utricular macula and that the sinusoidal component represents the translational oscillation of the statoconia. The model subsumes a hypothetical neural mechanism which allows x- and y-axis accelerations to be resolved. Derivation of equations of motion for the statoconial plaque in torsion and translation, which take into account forces acting in shear and normal to the macula, yield estimates of bias and sinusoidal components that are in qualitative agreement with the diverse experimental findings.
The feasibility of using free urease enzyme and ANGC-101 ion exchange resin to remove urea and ammonium ion for space system waste water applications was studied. Specifically examined is the prevention of urea and ammonia toxicity in a 30-day Orbiting Frog Otolith (OFO) flight experiment. It is shown that free urease enzyme used in conjunction with ANGC-101 ion-exchange resin and pH control can control urea and amonium ion concentration in unbuffered recirculating water. In addition, the resin does not adversely effect the bullfrogs by lowering the concentration of cations below critical minimum levels. Further investigations on bioburden control, frog waste excretion on an OFO diet, a trade-off analysis of methods of automating the urea/ammonium ion removal system and fabrication and test of a semiautomated breadboard were recommended as continuing efforts. Photographs of test equipment and test animals are shown.
This paper presents a model for the perception of dynamic orientation resulting from stimuli which involve both the otoliths and the semicircular canals. The model was applied to several multisensory stimuli and its predictions evaluated. In all cases, the model predictions were in substantial agreement with the known illusions or with the relevant experimental data.
Observations with three astronauts yielded two major findings. First, perceived self-motion during sinusoidal roll differed immediately postflight from preflight. Between 70 and 150 min after landing, roll was perceived primarily as linear translation. Secondly, more horizontal eye movement was elicited by roll simulation immediately postflight relative to both preflight and later postflight observations. These results support an 'otolith tilt-translation reinterpretation' hypothesis, which has clear implications for understanding astronaut reports of space motion sickness during the early period of orbital flight. A proposal for 'prophylactic adaptation training' which may provide preflight adaptation to weightlessness, derives from this reearch.