Eye movements and motion perception during off-vertical axis rotation after spaceflight

2013 ◽  
Vol 23 (1) ◽  
pp. 13-22 ◽  
Author(s):  
Gilles Clément ◽  
Scott J. Wood
Keyword(s):  
Eye Movements ◽  
Motion Perception ◽  
Vertical Axis ◽  
Axis Rotation

Eye Movements and Motion Perception Induced by Off-vertical Axis Rotation (OVAR) at Small Angles of Tilt after Spaceflight

1995 ◽  
Vol 115 (5) ◽  
pp. 603-609 ◽  
Author(s):  
Gilles Clement ◽  
Christian Darlot ◽  
Anna Petropoulos ◽  
Alain Berthoz
Keyword(s):  
Eye Movements ◽  
Motion Perception ◽  
Vertical Axis ◽  
Axis Rotation

The directions of nystagmus and apparent self-motion evoked by caloric tests and angular accelerations

2002 ◽  
Vol 11 (6) ◽  
pp. 349-355
Author(s):  
Ognyan I. Kolev
Keyword(s):  
Motion Perception ◽  
Frontal Plane ◽  
Vertical Axis ◽  
The Body ◽  
The Self ◽  
Whole Body ◽  
Caloric Stimulation ◽  
Infrared Video ◽  
Axis Rotation ◽  
Self Motion

Purpose: To further investigate the direction of (I) nystagmus and (II) self-motion perception induced by two stimuli: (a) caloric vestibular stimulations and (b) a sudden halt during vertical axis rotation. Subjects and methods: Twelve normal humans received caloric stimulation at 44°C, 30°C, and 20°C while in a supine position with the head inclined 30° upwards. In a second test they were rotated around the vertical axis with the head randomly placed in two positions: tilted 30° forward or tilted 60° backward, at a constant velocity of 90°/sec for 2 minutes and then suddenly stopped. After both tests they were asked to describe their sensations of self-motion. Eye movements were recorded with an infrared video-technique. Results: Caloric stimulation evoked only horizontal nystagmus in all subjects and induced a non-uniform complex perception of angular in frontal and transverse planes (the former dominated) and linear movements along the antero-posterior axis (sinking dominated) of the subject's coordinates. The self-motion was felt with the whole body or with a part of the body. Generally the perception evoked by cold (30°C) and warm (44°C) calorics was similar, although there were some differences. The stronger stimulus (20°C) evoked not only quantitative but also qualitative differences in perception. The abrupt halt of rotation induced self-motion perception and nystagmus only in the plane of rotation. The self-motion was felt with the whole body. Conclusion: There was no difference in the nystagmus evoked by caloric stimulation and a sudden halt of vertical axis rotation (in head positions to stimulate the horizontal canals); however, the two stimuli evoked different perceptions of self-motion. Calorics provoked the sensation of self-rotation in the frontal plane and linear motion, which did not correspond to the direction of nystagmus, as well as arcing and a reset phenomenon during angular and linear self-motion, caloric-induced self-motion can be felt predominantly or only with a part of the body, depending on the self-motion intensity. The findings indicate that, unlike the self-motion induced by sudden halt of vertical axis rotation, several mechanisms take part in generating caloric-induced self-motion.

Time Course and Magnitude of Illusory Translation Perception During Off-Vertical Axis Rotation

2006 ◽  
Vol 95 (3) ◽  
pp. 1571-1587 ◽  
Author(s):  
R.A.A. Vingerhoets ◽  
W. P. Medendorp ◽  
J.A.M. Van Gisbergen
Keyword(s):  
Motion Perception ◽  
Time Constant ◽  
Time Course ◽  
Interaction Model ◽  
Semicircular Canals ◽  
Vertical Axis ◽  
Original Proposal ◽  
Axis Rotation ◽  
Motion Percept ◽  
Self Motion

Human spatial orientation relies on vision, somatosensory cues, and signals from the semicircular canals and the otoliths. The canals measure rotation, whereas the otoliths are linear accelerometers, sensitive to tilt and translation. To disambiguate the otolith signal, two main hypotheses have been proposed: frequency segregation and canal–otolith interaction. So far these models were based mainly on oculomotor behavior. In this study we investigated their applicability to human self-motion perception. Six subjects were rotated in yaw about an off-vertical axis (OVAR) at various speeds and tilt angles, in darkness. During the rotation, subjects indicated at regular intervals whether a briefly presented dot moved faster or slower than their perceived self-motion. Based on such responses, we determined the time course of the self-motion percept and characterized its steady state by a psychometric function. The psychophysical results were consistent with anecdotal reports. All subjects initially sensed rotation, but then gradually developed a percept of being translated along a cone. The rotation percept could be described by a decaying exponential with a time constant of about 20 s. Translation percept magnitude typically followed a delayed increasing exponential with delays up to 50 s and a time constant of about 15 s. The asymptotic magnitude of perceived translation increased with rotation speed and tilt angle, but never exceeded 14 cm/s. These results were most consistent with predictions of the canal–otolith-interaction model, but required parameter values that differed from the original proposal. We conclude that canal–otolith interaction is an important governing principle for self-motion perception that can be deployed flexibly, dependent on stimulus conditions.

Compensatory and Orienting Eye Movements Induced By Off-Vertical Axis Rotation (OVAR) in Monkeys

2002 ◽  
Vol 88 (5) ◽  
pp. 2445-2462 ◽  
Author(s):  
Keisuke Kushiro ◽  
Mingjia Dai ◽  
Mikhail Kunin ◽  
Sergei B. Yakushin ◽  
Bernard Cohen ◽  
...  
Keyword(s):  
Eye Movements ◽  
Vertical Axis ◽  
Velocity Storage ◽  
Eye Position ◽  
Rotational Axis ◽  
Vestibuloocular Reflex ◽  
Time Constants ◽  
Head Velocity ◽  
Axis Rotation ◽  
Eye Velocity

Nystagmus induced by off-vertical axis rotation (OVAR) about a head yaw axis is composed of a yaw bias velocity and modulations in eye position and velocity as the head changes orientation relative to gravity. The bias velocity is dependent on the tilt of the rotational axis relative to gravity and angular head velocity. For axis tilts <15°, bias velocities increased monotonically with increases in the magnitude of the projected gravity vector onto the horizontal plane of the head. For tilts of 15–90°, bias velocity was independent of tilt angle, increasing linearly as a function of head velocity with gains of 0.7–0.8, up to the saturation level of velocity storage. Asymmetries in OVAR bias velocity and asymmetries in the dominant time constant of the angular vestibuloocular reflex (aVOR) covaried and both were reduced by administration of baclofen, a GABAB agonist. Modulations in pitch and roll eye positions were in phase with nose-down and side-down head positions, respectively. Changes in roll eye position were produced mainly by slow movements, whereas vertical eye position changes were characterized by slow eye movements and saccades. Oscillations in vertical and roll eye velocities led their respective position changes by ≈90°, close to an ideal differentiation, suggesting that these modulations were due to activation of the orienting component of the linear vestibuloocular reflex (lVOR). The beating field of the horizontal nystagmus shifted the eyes 6.3°/ g toward gravity in side down position, similar to the deviations observed during static roll tilt (7.0°/ g). This demonstrates that the eyes also orient to gravity in yaw. Phases of horizontal eye velocity clustered ∼180° relative to the modulation in beating field and were not simply differentiations of changes in eye position. Contributions of orientating and compensatory components of the lVOR to the modulation of eye position and velocity were modeled using three components: a novel direct otolith-oculomotor orientation, orientation-based velocity modulation, and changes in velocity storage time constants with head position re gravity. Time constants were obtained from optokinetic after-nystagmus, a direct representation of velocity storage. When the orienting lVOR was combined with models of the compensatory lVOR and velocity estimator from sequential otolith activation to generate the bias component, the model accurately predicted eye position and velocity in three dimensions. These data support the postulates that OVAR generates compensatory eye velocity through activation of velocity storage and that oscillatory components arise predominantly through lVOR orientation mechanisms.

scholarly journals Tilt and translation motion perception during off-vertical axis rotation

2007 ◽  
Vol 182 (3) ◽  
pp. 365-377 ◽  
Author(s):  
Scott J. Wood ◽  
Millard F. Reschke ◽  
Laura A. Sarmiento ◽  
Gilles Clément
Keyword(s):  
Motion Perception ◽  
Vertical Axis ◽  
Translation Motion ◽  
Axis Rotation

Off-Vertical Axis Rotation: A Test of the Otolith-Ocular Reflex

1992 ◽  
Vol 101 (8) ◽  
pp. 643-650 ◽  
Author(s):  
Joseph M. R. Furman ◽  
Robert H. Schor ◽  
Timothy L. Schumann
Keyword(s):  
Eye Movements ◽  
Semicircular Canal ◽  
Constant Velocity ◽  
Vertical Axis ◽  
Induced Response ◽  
Movement Response ◽  
Ocular Reflex ◽  
Vestibulo Ocular Reflex ◽  
Axis Rotation ◽  
Asymptomatic Subjects

The vestibulo-ocular reflex was studied via off-vertical axis rotation (OVAR) in the dark. The axis of the turntable could be tilted from vertical by up to 30°. Eye movements were measured with electro-oculography. Results from healthy asymptomatic subjects indicated that 1) a reliable otolith-induced response could be obtained during constant velocity OVAR using a velocity of 60°/s with a tilt of 30°; 2) constant velocity OVAR rotation was nausea-producing and, especially if subjects were rotated in the dark about an earth-vertical axis prior to being tilted, disorienting; and 3) sinusoidal OVAR produced minimal nausea; the eye movement response appeared to be the result of a combination of semicircular canal and otolith components. We conclude that OVAR has the potential of becoming a useful method for clinically assessing both the otolith-ocular reflex and semicircular canal—otolith interaction.

Eye movements induced by off-vertical axis rotation (OVAR) at small angles of tilt

1988 ◽  
Vol 73 (1) ◽  
pp. 91-105 ◽  
Author(s):  
C. Darlot ◽  
P. Denise ◽  
J. Droulez ◽  
B. Cohen ◽  
A. Berthoz
Keyword(s):  
Eye Movements ◽  
Vertical Axis ◽  
Axis Rotation
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