Vestibulo-Oculomotor Research in Space

Vestibulo-Oculomotor Research in Space PDF Author: Andrew H. Clarke
Publisher: Springer
ISBN: 331959933X
Category : Medical
Languages : en
Pages : 85

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Book Description
This monograph describes the findings of spaceflight research related to spatial orientation, sensorimotor coordination and mental function. Exposed to the microgravity conditions of spaceflight, the human experiences a variety of physiological and psychological problems, which are presented here. Recent findings of sensory motor research in space are depicted and their benefits for life on earth discussed. The examination of the vestibulo-oculomotor system for example has led to the development of innovative devices for the measurement of three-dimensional eye and head movements. These devices are currently employed in Earthbound applications such as eye laser surgery. The book is written for students and researchers in neurosciences, biomedical engineering, for neurologists and psychologists as well as for persons wanting to know more about biomedical research in space and its application on earth.

Vestibulo-Oculomotor Research in Space

Vestibulo-Oculomotor Research in Space PDF Author: Andrew H. Clarke
Publisher: Springer
ISBN: 331959933X
Category : Medical
Languages : en
Pages : 85

Get Book Here

Book Description
This monograph describes the findings of spaceflight research related to spatial orientation, sensorimotor coordination and mental function. Exposed to the microgravity conditions of spaceflight, the human experiences a variety of physiological and psychological problems, which are presented here. Recent findings of sensory motor research in space are depicted and their benefits for life on earth discussed. The examination of the vestibulo-oculomotor system for example has led to the development of innovative devices for the measurement of three-dimensional eye and head movements. These devices are currently employed in Earthbound applications such as eye laser surgery. The book is written for students and researchers in neurosciences, biomedical engineering, for neurologists and psychologists as well as for persons wanting to know more about biomedical research in space and its application on earth.

Studies of the Vestibulo-Ocular Reflex on Sts 4, 5 and 6

Studies of the Vestibulo-Ocular Reflex on Sts 4, 5 and 6 PDF Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722817213
Category :
Languages : en
Pages : 44

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Book Description
The vestibulo-ocular reflex (VOR) may be altered by weightlessness. Since this reflex plays a large role in visual stabilization, it was important to document any changes caused by space flight. This is a report on findings on STS-4 through 6 and is part of a larger study of neurosensory adaptation done on STS-4 through 8. Voluntary horizontal head oscillations at 1/3 Hz with amplitude of 30 deg right and left of center were recorded by a potentiometer and compared to eye position recorded by electroculography under the following conditions: eyes open, head fixed, tracking horizontal targets switched 0, 15, and 30 degrees right and left (optokinetic reflex - OKR - and calibration); eyes open and fixed on static external target with oscillation, (vestibulo ocular reflex, eyes closed - VOR EC); eyes open and wearing opaque goggles with target fixed in imagination (vestibulo-ocular reflex, eyes shaded - VOR ES); and eyes open and fixed on a head synchronized target with head oscillation (VOR suppression). No significant changes were found in voluntary head oscillation frequency or amplitude in those with (n=5), and without (n=3), space motion sickness (SMS), with phase of flight or test condition. Variations in head oscillation were too small to have produced detectable changes in test results. Thornton, William E. and Pool, Sam L. and Moore, Thomas P. and Uri, John J. Johnson Space Center RTOP 073-36-00-00-72...

Oculomotor Systems and Perception

Oculomotor Systems and Perception PDF Author: Sheldon M. Ebenholtz
Publisher: Cambridge University Press
ISBN: 0521804590
Category : Medical
Languages : en
Pages : 236

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Book Description
This 2001 text was the first to emphasize the role of oculomotor systems in perception. Oculomotor systems that regulate eye movements play an important role in accounting for certain qualities of visual experience. They are implicated in a wide array of perceptual topics, from apparent size, depth, and distance, to apparent slant and vertical orientation. The text begins with a brief introduction to the basic characteristics of such oculomotor systems as those controlling vergence, pursuit, the vestibulo-ocular response, and saccadic eye movements. Also introduced are fundamental concepts in physiological optics. Next explored are mechanisms of perception, with a particular focus on eye movements, and the remarkably diverse implications of oculomotor research, which extend to motion sickness and life in space orbit. Insights into dysfunctional vision are also offered. This book complements standard texts on visual perception, yet may be read independently by those with a modest background in vision science.

Visual Suppression of the Vestibulo-Ocular Reflex During Space Flight

Visual Suppression of the Vestibulo-Ocular Reflex During Space Flight PDF Author: National Aeronautics and Space Adm Nasa
Publisher: Independently Published
ISBN: 9781792975257
Category :
Languages : en
Pages : 30

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Book Description
Visual suppression of the vestibulo-ocular reflex was studied in 16 subjects on 4 Space Shuttle missions. Eye movements were recorded by electro-oculography while subjects fixated a head mounted target during active sinusoidal head oscillation at 0.3 Hz. Adequacy of suppression was evaluated by the number of nystagmus beats, the mean amplitude of each beat, and the cumulative amplitude of nystagmus during two head oscillation cycles. Vestibulo-ocular reflex suppression was unaffected by space flight. Subjects with space motion sickness during flight had significantly more nystagmus beats than unaffected individuals. These susceptible subjects also tended to have more nystagmus beats before flight. Uri, John J. and Thornton, William E. and Moore, Thomas P. and Pool, Sam L. Johnson Space Center NASA-TM-102157, S-598, NAS 1.15:102157 RTOP 073-36-00-00-72...

Fifth Symposium on the Role of the Vestibular Organs in Space Exploration

Fifth Symposium on the Role of the Vestibular Organs in Space Exploration PDF Author:
Publisher:
ISBN:
Category : Gravitation
Languages : en
Pages : 292

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Book Description


Current Oculomotor Research

Current Oculomotor Research PDF Author: Wolfgang Becker
Publisher: Springer Science & Business Media
ISBN: 1475730543
Category : Medical
Languages : en
Pages : 459

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Book Description
This volume contains the proceedings of the Ninth European Conference on Eye Movements (ECEM 9), held in Ulm, Germany, on September 23-26, 1997. ECEM 9 con tinued a series of conferences initiated by Rudolf Groner of Bern, Switzerland, in 1981 which, from its very beginning, has brought together scientists from very diverse fields with a common interest in eye movements. About 40 of the papers presented at ECEM 9 have been selected for presentation in full length while others are rendered in condensed form. There is a broad spectrum of motives why people have become involved in, and fas cinated by, eye movement research. Neuroscientists have been allured by the prospect of understanding anatomical findings, single unit recordings, and the sequels of experimental lesions in terms of the clearly defined system requirements and the well documented be havioural repertoire of the oculomotor system. Others have been attracted by the richness of this repertoire and its dependence on an intricate hierarchy of factors spanning from "simple" reflexes to visual pattern recognition and spatio-temporal prediction. Neurolo gists, neuro-ophthalmologists and neuro-otologists have long standing experience with eye movements as sensitive indicators of lesions in the brain stem, the midbrain, and the cere bellum. By studying oculomotor malfunctions they have made, and are continuing to make, important contributions to our understanding of oculomotor functions.

Studies of the Horizontal Vestibulo-Ocular Reflex on Sts 7 and 8

Studies of the Horizontal Vestibulo-Ocular Reflex on Sts 7 and 8 PDF Author: National Aeronautics and Space Adm Nasa
Publisher: Independently Published
ISBN: 9781730717611
Category : Science
Languages : en
Pages : 56

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Book Description
Unpaced voluntary horizontal head oscillation was used to study the Vestibulo-Ocular Reflex (VOR) on Shuttle flights STS 7 and 8. Ten subjects performed head oscillations at 0.33 Hz + or - 30 deg amplitude under the followng conditions: VVOR (visual VOR), eyes open and fixed on a stationary target; VOR-EC, with eyes closed and fixed on the same target in imagination; and VOR-S (VOR suppression), with eyes open and fixed on a head-synchronized target. Effects of weightlessness, flight phase, and Space Motion Sickness (SMS) on head oscillation characteristics were examined. A significant increase in head oscillation frequency was noted inflight in subjects free from SMS. In subjects susceptible to SMS, frequency was reduced during their Symptomatic period. The data also suggest that the amplitude and peak velocity of head oscillation were reduced early inflight. No significant changes were noted in reflex gain or phase in any of the test conditions; however, there was a suggestion of an increase in VVOR and VOR-ES gain early inflight in asymptomatic subjects. A significant difference in VOR-S was found between SMS susceptible and non-susceptible subjects. There is no evidence that any changes in VOR characteristics contributed to SMS. Thornton, William E. and Uri, John J. and Moore, Thomas P. and Pool, Sam L. Johnson Space Center...

Visual Suppression of the Vestibulo-ocular Reflex During Space Flight

Visual Suppression of the Vestibulo-ocular Reflex During Space Flight PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 20

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Book Description


Eye and Head Motion During Head Turns in Spaceflight

Eye and Head Motion During Head Turns in Spaceflight PDF Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722226244
Category :
Languages : en
Pages : 28

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Book Description
Eye-head motion was studied pre-, in- and postflight during single voluntary head turns. A transient increase in vestibulo-ocular reflex (VOR) gain occurred early in the flight, but later trended toward normal. This increased gain was produced by a relative increase in eye counterrotation velocity. Asymmetries in gain with right and left turns also occurred, caused by asymmetries in eye counterrotation velocities. These findings were remarkably similar to those from Soviet primate studies using gaze fixation targets, except the human study trended more rapidly toward normal. These findings differ substantially from those measuring VOR gain by head oscillation, in which no significant changes were found inflight. No visual disturbances were noted in either test condition or in normal activities. These head turn studies are the only ones to date documenting any functional change in VOR in weightlessness. Thornton, William E. and Uri, John J. and Moore, Thomas P. and Pool, Sam L. Johnson Space Center RTOP 073-36-00-00-72...

Reduction of Ocular Counter-Rolling by Adaptation to Space

Reduction of Ocular Counter-Rolling by Adaptation to Space PDF Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722726355
Category :
Languages : en
Pages : 24

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Book Description
We studied the three-dimensional vestibulo-ocular reflex (VOR) of rhesus monkeys before and after the COSMOS Biosatellite 2229 Mission of 1992-1993. This included tests of ocular counter-rolling (OCR), the gain of the vestibulo-ocular reflex (VOR), and spatial orientation of velocity storage. A four-axis vestibular and oculomotor stimulator was transported to the Institute of Biomedical Problems in Moscow for the pre- and postflight ground-based testing. Twelve normal juvenile male rhesus monkey were implanted surgically with eye coils and tested 60-90 days before spaceflight. Two monkey (7906 and 6151), selected from the twelve as flight animals, flew from 12/29/92 to 1/10/93. Upon recovery, they were tested for 11 days postflight along with three control animals. Compensatory ocular torsion was produced in two ways: (1) Lateral head tilts evoked OCR through otolith-ocular reflexes. OCR was also measured dynamically during off-vertical axis rotation (OVAR). (2) Rotation about a naso-occipital axis that was either vertical of horizontal elicited torsional nystagmus through semicircular canal-ocular reflexes (roll VOR). OCR from the otoliths was substantially reduced (70 percent) for 11 days after reentry on both modes of testing. The gain of the roll VOR was also decreased, but less than OCR. These data demonstrate that there was a long-lasting depression of torsional or roll eye movements after adaptation to microgravity in these monkeys, especially those movements produced by the otolith organs. Dai, Mingjia and Mcgarvie, Leigh and Kozlovskaya, Inessa and Sirota, Mischa and Raphan, Theodore and Cohen, Bernard Unspecified Center NAG2-573; NAG2-703...