“Torso Rotation” Experiments; 2: Gaze Stability During Voluntary Head Movements Improves with Adaptation to Motion Sickness

1996 ◽  
Vol 6 (5) ◽  
pp. 377-385
Author(s):  
L.J.G. Bouyer ◽  
D.G.D. Watt
Keyword(s):  
Motion Sickness ◽  
Head Movements ◽  
Gaze Stability

“Torso Rotation”' experiments. 4: the role of vision and the cervico-ocular reflex in compensation for a deficient VOR

1999 ◽  
Vol 9 (2) ◽  
pp. 89-101
Author(s):  
L.J.G. Bouyer ◽  
D.G.D. Watt
Keyword(s):  
Motion Sickness ◽  
Vestibular Function ◽  
Repeated Exposure ◽  
Head Movements ◽  
Upper Body ◽  
Calibration Data ◽  
En Bloc ◽  
Mean Velocity ◽  
Gaze Stability ◽  
Velocity Gain

Acute, reversible changes in human vestibular function can be produced by exposure to “Torso Rotation” (TR), a method involving the overuse of certain types of simple, self-generated movements. A single session results in multiple, short-lasting aftereffects, including perceptual illusions, VOR gain reduction,gaze and postural instability, and motion sickness. With repeated exposure, motion sickness susceptibility disappears and gaze stability improves. VOR gain continues to be reduced, however. Therefore, another gaze stabilizing system must come into play. Are visual and/or neck inputs involved in this functional compensation? Six subjects participated in this 7-day experiment. Eye and head movements were measured during 2 tests: 1) voluntary “head only” shaking between 0.3 and 3.0 Hz (lights off) and 2) voluntary “head and torso” shaking, moving the upper body en bloc (neck immobilized). Measurements were obtained before and repeatedly after TR. Velocity gain (eye velocity/head velocity) was determined for each of these tests. Each day, mean velocity gain during “head only” shaking in the dark (averaged over 1.0 to 2.0 Hz) dropped significantly after TR ( P < 0.01), with no long-term improvement ( P > 0.9). Similar results, although more noisy, were obtained for “head and torso” shaking. As a control, EOG calibration data confirmed that gaze stability in the light did improve over the 7 days of testing. This experiment demonstrates that the reduction in gaze instability following repeated exposure to TR results from an increased use of vision. It excludes the VOR, the COR, and predictive mechanisms (including efference copy) as contributors. In addition, in the 20 minutes following TR completion, gaze stability recovered less than during previous VOR testing in the dark. These results are compatible with the motion that exposure to TR leads to a change in sensorimotor strategy involving a de-emphasis of vestibular inputs.

Visually Induced Motion Sickness in Virtual Environments

1992 ◽  
Vol 1 (3) ◽  
pp. 306-310 ◽  
Author(s):  
Lawrence J. Hettinger ◽  
Gary E. Riccio
Keyword(s):  
Virtual Environments ◽  
Motion Sickness ◽  
Visual Representations ◽  
Visual Display ◽  
Critical Issue ◽  
Head Movements ◽  
Visually Induced Motion Sickness ◽  
Induced Motion ◽  
Self Motion ◽  
The Relationship

Visually induced motion sickness is a syndrome that occasionally occurs when physically stationary individuals view compelling visual representations of self-motion. It may also occur when detectable lags are present between head movements and recomputation and presentation of the visual display in helmet-mounted displays. The occurrence of this malady is a critical issue for the future development and implementation of virtual environments. Applications of this emerging technology are likely to be compromised to the extent that users experience illness and/or incapacitation. This article presents an overview of what is currently known regarding the relationship between visually specified self-motion in the absence of inertial displacement and resulting illness and perceptual-motor disturbances.

Adaptation of the vestibulo-ocular reflex, subjective tilt, and motion sickness to head movements during short-radius centrifugation

2003 ◽  
Vol 13 (2-3) ◽  
pp. 65-77
Author(s):  
Laurence R. Young ◽  
Kathleen H. Sienko ◽  
Lisette E. Lyne ◽  
Heiko Hecht ◽  
Alan Natapoff
Keyword(s):  
Motion Sickness ◽  
Body Position ◽  
Rest Period ◽  
Vertical Axis ◽  
Head Movements ◽  
Whole Body ◽  
Slow Phase ◽  
Ocular Reflex ◽  
Vestibulo Ocular Reflex ◽  
Angular Velocities

Head movements made while the whole body is rotating at unusually high angular velocities (here with supine body position about an earth-vertical axis) result in inappropriate eye movements, sensory illusions, disorientation, and frequently motion sickness. We investigated the acquisition and retention of sensory adaptation to cross-coupled components of the vestibulo-ocular reflex (VOR) by asking eight subjects to make headturns while being rotated at 23 rpm on two consecutive days, and again a week later. The dependent measures were inappropriate vertical VOR, subjective tilt, and motion sickness in response to 90° yaw out-of-plane head movements. Motion sickness was evaluated during and following exposure to rotation. Significant adaptation effects were found for the slow phase velocity of vertical nystagmus, the reported magnitude of the subjective tilt experienced during head turns, and motion-sickness scores. Retention of adaptation over a six-day rest period without rotation occurred, but was not complete for all measures. Adaptation of VOR was fully maintained while subjective tilt was only partially maintained and motion-sickness scores continued to decrease. Practical implications of these findings are discussed with particular emphasis on artificial gravity, which could be produced in weightlessness by means of a short-radius (2 m) rotator.

1P1-A26 Analysis of Head Movements of Automobile Passenger using A Mathematical Model of Motion Sickness

2010 ◽  
Vol 2010 (0) ◽  
pp. _1P1-A26_1-_1P1-A26_4
Author(s):  
Satoru Fujisawa ◽  
Katsuya Imaizumi ◽  
Takahiro Wada ◽  
Norimasa Kamiji ◽  
Shun'ichi Doi
Keyword(s):  
Mathematical Model ◽  
Motion Sickness ◽  
Head Movements

Vestibular Gaze Stabilization: Different Behavioral Strategies for Arboreal and Terrestrial Avians

2005 ◽  
Vol 93 (3) ◽  
pp. 1165-1173 ◽  
Author(s):  
Asim Haque ◽  
J. David Dickman
Keyword(s):  
Avian Species ◽  
Head Movements ◽  
Head Motion ◽  
Behavioral Strategies ◽  
Specific Behavior ◽  
Gaze Stabilization ◽  
High Frequencies ◽  
Gaze Stability ◽  
Species Specific

In birds, it is thought that head movements play a major role in the reflexive stabilization of gaze and vision. In this study, we investigated the contributions of the eye and head to gaze stabilization during rotations under both head-fixed [vestibuloocular (VOR)] and head-free conditions in two avian species: pigeons and quails. These two species differ both in ocular anatomy (the pigeon has 2 distinct foveal regions), as well as in behavioral repertoires. Pigeons are arboreal, fly extended distances, and can navigate. Quails are primarily engrossed in terrestrial niches and fly only short distances. Unlike the head-fixed VOR gains that were under-compensatory for both species, gaze gains under head-free conditions were completely compensatory at high frequencies. This compensation was achieved primarily with head movements in pigeons, but with combined head and eye-in-head contributions in the quail. In contrast, eye-in-head motion, which was significantly reduced for head-free compared with head-fixed conditions, contributed very little to overall gaze stability in pigeons. These results suggest that disparity between the stabilization strategies employed by these two birds may be attributed to differences in species-specific behavior and anatomy.

Effect of radius versus rotation speed in artificial gravity

2008 ◽  
Vol 17 (5-6) ◽  
pp. 333-346
Author(s):  
Jan E. Holly
Keyword(s):  
Motion Sickness ◽  
Head Movement ◽  
Rotation Speed ◽  
Head Movements ◽  
Three Dimensions ◽  
Artificial Gravity ◽  
Whole Body ◽  
Movement Direction ◽  
Least Disturbance ◽  
Significant Disturbance

Artificial gravity by centrifugation can lead to perceptual disturbances in the form of motion sickness and/or misperception of motion during head movements, but the degree of perceptual disturbance during centrifugation in 0-g has not been thoroughly investigated. It is known that during whole-body on-axis yaw rotation in 0-g, head movements in pitch and roll cause very little disturbance, despite significant disturbance in 1-g. Therefore, 1-g experimental results do not apply directly to 0-g without further analysis. A modeling approach was used here to predict disorienting effects in 0-g and 1-g environments, with different rotation speeds, centrifuge radii, and directions of head movement. The results were based upon investigation of the stimulus itself, in the form of angular and linear accelerations, and their consequences due to linear-angular interactions in three dimensions. The results explain known differences in 0-g and 1-g, for head turns toward and away from the direction of motion, and for head movements on- and off-axis. Additional predictions include an increase in perceptual disturbance with the magnitude of the gravito-inertial acceleration (GIA), therefore an increase off-axis, but a decrease in 0-g. Also predicted is that head-movement direction makes a difference, with rotation outward relative to the centrifuge axis causing the least disturbance.

Roles of Head, Gaze, and Spatial Orientation in the Production of Oscillopsia

1991 ◽  
Vol 1 (3) ◽  
pp. 215-222
Author(s):  
Masahiro Takahashi ◽  
Yukihiro Okada ◽  
Akira Saito ◽  
Yasuhiko Takei ◽  
Ikuko Tomizawa ◽  
...  
Keyword(s):  
Spatial Orientation ◽  
High Frequency ◽  
Normal Subjects ◽  
Head Movements ◽  
Body Movements ◽  
Blurred Vision ◽  
Body Balance ◽  
Gaze Stability ◽  
Surrounding Space ◽  
Horizontal Rotations

To clarify the factors causing oscillopsia, we investigated head movement, gaze stability, and perception under various situations. High-frequency head movements, whether they were horizontal rotations or passively induced vertical oscillations, produced blurred vision and gaze fluctuations in patients with labyrinthine loss. However, this sensation differed from the oscillopsia perceived during walking, as it did not involve a sensation of oscillation of the surrounding space or a loss of body balance. Although patients with labyrinthine loss showed large irregular head perturbations during stepping, the resultant retinal velocity slips seemed too small to explain oscillopsia. Walking while wearing horizontal reversing prisms produced loss of spatial orientation, dysequilibrium, and instability of vision in normal subjects, which resembled the symptoms found in patients with oscillopsia. The present study suggests that oscillopsia represents a perceptual inability to detect spatial orientation during head or body movements rather than a mere blurring of vision caused by deficient compensation.

Vestibular suppression during space flight

2003 ◽  
Vol 13 (4-6) ◽  
pp. 363-376
Author(s):  
Douglas Watt ◽  
Luc Lefebvre
Keyword(s):  
Motion Sickness ◽  
Space Flight ◽  
Recent Experiment ◽  
Underlying Mechanism ◽  
Head Movements ◽  
Space Motion Sickness ◽  
Motor Strategy ◽  
Space Motion ◽  
The Subject ◽  
Similar Motor

Normal movements performed while voluntarily fixing the head to the torso can lead to motion sickness in susceptible individuals. The underlying mechanism may involve excessive suppression of vestibular responses. A similar motor strategy is often adopted in the early days of a space flight and might contribute to the development of space motion sickness. In a recent experiment, we monitored the eye, head and upper torso rotations of four Life and Microgravity Spacelab crew members. For the purposes of this study, all data were excluded except for periods during which the subject was performing pure yaw-axis head movements. All subjects showed a significant increase in gaze slip on the first day of their mission, suggesting that increased vestibular suppression was occurring. Furthermore, this amount of increased suppression would have been more than adequate to produce motion sickness in susceptible individuals on the ground. The results support the theory of two, independent mechanisms for space motion sickness.

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