Aerospace medicine and biology: A continuing bibliography with indexes, supplement 130, July 1974

This special bibliography lists 291 reports, articles, and other documents introduced into the NASA scientific and technical information system in June 1974

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

The Impact of Power Training on Balance and Visual Feedback Removal

Because power training has been known to augment stability, the purpose of this study was to assess whether the removal of visual input affects lower limb muscle power production in young women who are resistance trained to the same degree it affects the untrained. This provided insight as far as the need for resistance training protocols in a largely untrained visually impaired population. To study this, fourteen college-aged female participants (18-23 years) performed a seated double-leg press on a leg sled machine, isolating power production of the lower limbs. After establishing baselines, which involved finding an average of power produced during five trials, the subjects were asked to close their eyes for the following set of five pushes. The power production was assessed by utilizing a Tendo Unit, with placement on one of the limbs of the machine, to measure power output during leg extension (measured in Watts). Statistics analyzed in SPSS determined the average power deficit of the athletic population to be 11.57 Watts, whereas the general population had an average power deficit of 37.43 Watts. The deficits experienced by each respective group upon visual removal were significantly different from one another, as evidenced by a p-value of .048. This accentuated the power-trained group’s resilience. A suggested training plan regimen including cardiorespiratory, resistance, flexibility, and neuromotor exercises has been appended for persons experiencing visual impairment and seeking to better their balance through power

Electrical vestibular stimulation in humans. A narrative review

Background: In patients with bilateral vestibulopathy, the regular treatment options, such as medication, surgery, and/ or vestibular rehabilitation, do not always suffice. Therefore, the focus in this field of vestibular research shifted to electri- cal vestibular stimulation (EVS) and the development of a system capable of artificially restoring the vestibular func- tion. Key Message: Currently, three approaches are being investigated: vestibular co-stimulation with a cochlear im- plant (CI), EVS with a vestibular implant (VI), and galvanic vestibular stimulation (GVS). All three applications show promising results but due to conceptual differences and the experimental state, a consensus on which application is the most ideal for which type of patient is still missing. Summa- ry: Vestibular co-stimulation with a CI is based on “spread of excitation,” which is a phenomenon that occurs when the currents from the CI spread to the surrounding structures and stimulate them. It has been shown that CI activation can indeed result in stimulation of the vestibular structures. Therefore, the question was raised whether vestibular co- stimulation can be functionally used in patients with bilat- eral vestibulopathy. A more direct vestibular stimulation method can be accomplished by implantation and activa- tion of a VI. The concept of the VI is based on the technology and principles of the CI. Different VI prototypes are currently being evaluated regarding feasibility and functionality. So far, all of them were capable of activating different types of vestibular reflexes. A third stimulation method is GVS, which requires the use of surface electrodes instead of an implant- ed electrode array. However, as the currents are sent through the skull from one mastoid to the other, GVS is rather unspe- cific. It should be mentioned though, that the reported spread of excitation in both CI and VI use also seems to in- duce a more unspecific stimulation. Although all three ap- plications of EVS were shown to be effective, it has yet to be defined which option is more desirable based on applicabil- ity and efficiency. It is possible and even likely that there is a place for all three approaches, given the diversity of the pa- tient population who serves to gain from such technologies

Summer Institute in Space Biology Final report, Apr. 1 - Nov. 30, 1968

Space biology laboratory on effects of aerospace environments on physiological and psychological performance of astronaut

Structural elements in the concept of motion sickness

Structural elements in concept of motion sicknes

Aerospace medicine and biology. A continuing bibliography (supplement 231)

This bibliography lists 284 reports, articles, and other documents introduced into the NASA scientific and technical information system in March 1982

Aerospace Medicine and Biology: A continuing bibliography with indexes, supplement 144

This bibliography lists 257 reports, articles, and other documents introduced into the NASA scientific and technical information system in July 1975

Perception of the Body in Space: Mechanisms

The principal topic is the perception of body orientation and motion in space and the extent to which these perceptual abstraction can be related directly to the knowledge of sensory mechanisms, particularly for the vestibular apparatus. Spatial orientation is firmly based on the underlying sensory mechanisms and their central integration. For some of the simplest situations, like rotation about a vertical axis in darkness, the dynamic response of the semicircular canals furnishes almost enough information to explain the sensations of turning and stopping. For more complex conditions involving multiple sensory systems and possible conflicts among their messages, a mechanistic response requires significant speculative assumptions. The models that exist for multisensory spatial orientation are still largely of the non-rational parameter variety. They are capable of predicting relationships among input motions and output perceptions of motion, but they involve computational functions that do not now and perhaps never will have their counterpart in central nervous system machinery. The challenge continues to be in the iterative process of testing models by experiment, correcting them where necessary, and testing them again

To develop behavioral tests of vestibular functioning in the Wistar rat

Two tests of vestibular functioning in the rat were developed. The first test was the water maze. In the water maze the rat does not have the normal proprioceptive feedback from its limbs to help it maintain its orientation, and must rely primarily on the sensory input from its visual and vestibular systems. By altering lighting conditions and visual cues the vestibular functioning without visual cues was assessed. Whether there was visual compensation for some vestibular dysfunction was determined. The second test measured vestibular functioning of the rat's behavior on a parallel swing. In this test the rat's postural adjustments while swinging on the swing with the otoliths being stimulated were assessed. Less success was achieved in developing the parallel swing as a test of vestibular functioning than with the water maze. The major problem was incorrect initial assumptions of what the rat's probable behavior on the parallel swing would be