The influence of light on modulation of the human vestibulo-ocular reflex

2000 ◽  
Vol 10 (1) ◽  
pp. 51-55
Author(s):  
Vallabh E. Das ◽  
Stacy Yaniglos ◽  
R. John Leigh
Keyword(s):  
Eye Movements ◽  
Contact Lenses ◽  
Mental Arithmetic ◽  
Peak Velocity ◽  
Target Information ◽  
Stationary Target ◽  
Retinal Slip ◽  
Ocular Reflex ◽  
Vestibulo Ocular Reflex ◽  
Head Rotations

The goal of this study was to investigate the influence of light, without retinal slip information, on the ability to generate eye movements to compensate for head rotations. Subjects were rotated sinusoidally at 1.0, 2.0 or 3.0 Hz at a peak velocity of 30 deg/sec while they: 1) performed mental arithmetic in darkness; 2) attempted to view the remembered location of a stationary target in darkness; 3) attempted to view the remembered location of the stationary target through translucent contact lenses that allowed the passage of light but did not provide any target information (ganzfeld stimulus); 4) directly viewed the illuminated stationary target. The gain of compensatory eye movements was least while subjects viewed through the translucent contact lenses (median = 0.76), intermediate while subjects either performed mental arithmetic in darkness (median = 0.84) or attempted to view the remembered location of the target in darkness (median = 0.84), and greatest if they actually viewed the target (median = 0.95). Our findings suggest that factors other than light alone account for the increased gain of compensatory eye movements that occurs when subjects view rather than imagine a stationary target.

scholarly journals Enhancement of the Vestibulo-Ocular Reflex by Prior Eye Movements

1999 ◽  
Vol 81 (6) ◽  
pp. 2884-2892 ◽  
Author(s):  
Vallabh E. Das ◽  
Louis F. Dell’Osso ◽  
R. John Leigh
Keyword(s):  
Eye Movements ◽  
Smooth Pursuit ◽  
Initial Perturbation ◽  
Head Rotation ◽  
Gaze Shift ◽  
Stationary Target ◽  
Ocular Reflex ◽  
Vestibulo Ocular Reflex ◽  
Head Rotations ◽  
Horizontal Head

Enhancement of the vestibulo-ocular reflex by prior eye movements. We investigated the effect of visually mediated eye movements made before velocity-step horizontal head rotations in eleven normal human subjects. When subjects viewed a stationary target before and during head rotation, gaze velocity was initially perturbed by ∼20% of head velocity; gaze velocity subsequently declined to zero within ∼300 ms of the stimulus onset. We used a curve-fitting procedure to estimate the dynamic course of the gain throughout the compensatory response to head rotation. This analysis indicated that the median initial gain of compensatory eye movements (mainly because of the vestibulo-ocular reflex, VOR) was 0.8 and subsequently increased to 1.0 after a median interval of 320 ms. When subjects attempted to fixate the remembered location of the target in darkness, the initial perturbation of gaze was similar to during fixation of a visible target (median initial VOR gain 0.8); however, the period during which the gain increased toward 1.0 was >10 times longer than that during visual fixation. When subjects performed horizontal smooth-pursuit eye movements that ended (i.e., 0 gaze velocity) just before the head rotation, the gaze velocity perturbation at the onset of head rotation was absent or small. The initial gain of the VOR had been significantly increased by the prior pursuit movements for all subjects ( P < 0.05; mean increase of 11%). In four subjects, we determined that horizontal saccades and smooth tracking of a head-fixed target (VOR cancellation with eye stationary in the orbit) also increased the initial VOR gain (by a mean of 13%) during subsequent head rotations. However, after vertical saccades or smooth pursuit, the initial gaze perturbation caused by a horizontal head rotation was similar to that which occurred after fixation of a stationary target. We conclude that the initial gain of the VOR during a sudden horizontal head rotation is increased by prior horizontal, but not vertical, visually mediated gaze shifts. We postulate that this “priming” effect of a prior gaze shift on the gain of the VOR occurs at the level of the velocity inputs to the neural integrator subserving horizontal eye movements, where gaze-shifting commands and vestibular signals converge.

Eye-Head Movement Coordination: Vestibulo-Ocular Reflex Suppression with Head-Fixed Target Fixation1

1991 ◽  
Vol 1 (2) ◽  
pp. 161-170
Author(s):  
Jean-Louis Vercher ◽  
Gabriel M. Gauthier
Keyword(s):  
Eye Movements ◽  
Time Course ◽  
Mental Arithmetic ◽  
Visual Space ◽  
Head Movements ◽  
Total Darkness ◽  
Fixed Target ◽  
Ocular Reflex ◽  
Optokinetic Reflex ◽  
Vestibulo Ocular Reflex

To maintain clear vision, the images on the retina must remain reasonably stable. Head movements are generally dealt with successfully by counter-rotation of the eyes induced by the combined actions of the vestibulo-ocular reflex (VOR) and the optokinetic reflex. A problem of importance relates to the value of the so-called intrinsic gain of the VOR (VORG) in man, and how this gain is modulated to provide appropriate eye movements. We have studied these problems in two situations: 1. fixation of a stationary object of the visual space while the head moves; 2. fixation of an object moving with the head. These two situations were compared to a basic condition in which no visual target was allowed in order to induce “pure” VOR. Eye movements were recorded in seated subjects during stationary sinusoidal and transient rotations around the vertical axis. Subjects were in total darkness (DARK condition) and involved in mental arithmetic. Alternatively, they were provided with a small foveal target, either fixed with respect to earth (earth-fixed target: EFT condition), or moving with them (chair-fixed-target: CFT condition). The stationary rotation experiment was used as baseline for the ensuing experiment and yielded control data in agreement with the literature. In all 3 visual conditions, typical responses to transient rotations were rigorously identical during the first 200 ms. They showed, sequentially, a 16-ms delay of the eye behind the head and a rapid increase in eye velocity during 75 to 80 ms, after which the average VORG was 0.9 ± 0.15. During the following 50 to 100 ms, the gain remained around 0.9 in all three conditions. Beyond 200 ms, the VORG remained around 0.9 in DARK and increased slowly towards 1 or decreased towards zero in the EFT and CFT conditions, respectively. The time-course of the later events suggests that visual tracking mechanisms came into play to reduce retinal slip through smooth pursuit, and position error through saccades. Our data also show that in total darkness VORG is set to 0.9 in man. Lower values reported in the literature essentially reflect predictive properties of the vestibulo-ocular mechanism, particularly evident when the input signal is a sinewave.

Oculomotor Control of Primary Eye Position Discriminates Between Translation and Tilt

1999 ◽  
Vol 81 (1) ◽  
pp. 394-398 ◽  
Author(s):  
Bernhard J. M. Hess ◽  
Dora E. Angelaki
Keyword(s):  
Dynamic Control ◽  
Linear Acceleration ◽  
Oculomotor System ◽  
Oculomotor Control ◽  
Eye Position ◽  
Axis Orientation ◽  
Fast Phase ◽  
Ocular Reflex ◽  
Vestibulo Ocular Reflex ◽  
Head Rotations

Hess, Bernhard J. M. and Dora E. Angelaki. Oculomotor control of primary eye position discriminates between translation and tilt. J. Neurophysiol. 81: 394–398, 1999. We have previously shown that fast phase axis orientation and primary eye position in rhesus monkeys are dynamically controlled by otolith signals during head rotations that involve a reorientation of the head relative to gravity. Because of the inherent ambiguity associated with primary otolith afferent coding of linear accelerations during head translation and tilts, a similar organization might also underlie the vestibulo-ocular reflex (VOR) during translation. The ability of the oculomotor system to correctly distinguish translational accelerations from gravity in the dynamic control of primary eye position has been investigated here by comparing the eye movements elicited by sinusoidal lateral and fore-aft oscillations (0.5 Hz ± 40 cm, equivalent to ± 0.4 g) with those during yaw rotations (180°/s) about a vertically tilted axis (23.6°). We found a significant modulation of primary eye position as a function of linear acceleration (gravity) during rotation but not during lateral and fore-aft translation. This modulation was enhanced during the initial phase of rotation when there was concomitant semicircular canal input. These findings suggest that control of primary eye position and fast phase axis orientation in the VOR are based on central vestibular mechanisms that discriminate between gravity and translational head acceleration.

scholarly journals New advances regarding adaptation of the vestibulo-ocular reflex

2019 ◽  
Vol 122 (2) ◽  
pp. 644-658 ◽  
Author(s):  
Michael C. Schubert ◽  
Americo A. Migliaccio
Keyword(s):  
Training Session ◽  
Whole Body ◽  
Velocity Error ◽  
Ocular Reflex ◽  
Vestibulo Ocular Reflex ◽  
Vor Adaptation ◽  
Effects Of Aging ◽  
Repeated Training ◽  
Head Rotations ◽  
Efferent Vestibular System

This is a review summarizing the development of vestibulo-ocular reflex (VOR) adaptation behavior with relevance to rehabilitation over the last 10 years and examines VOR adaptation using head-on-body rotations, specifically the influence of training target contrast, position and velocity error signal, active vs. passive head rotations, and sinusoidal vs. head impulse rotations. This review discusses optimization of the single VOR adaptation training session, consolidation between repeated training sessions, and dynamic incremental VOR adaptation. Also considered are the effects of aging and the roles of the efferent vestibular system, cerebellum, and otoliths on angular VOR adaptation. Finally, this review examines VOR adaptation findings in studies using whole body rotations.

scholarly journals Eye movements and vestibulo-ocular reflex in the blind

1987 ◽  
Vol 234 (5) ◽  
pp. 337-341 ◽  
Author(s):  
D. K�mpf ◽  
H.-F. Piper
Keyword(s):  
Eye Movements ◽  
Ocular Reflex ◽  
Vestibulo Ocular Reflex

Ocular Responses to Head Rotations During Mirror Viewing

2001 ◽  
Vol 86 (5) ◽  
pp. 2323-2329 ◽  
Author(s):  
Yanning Han ◽  
Jeffrey T. Somers ◽  
Jae I. Kim ◽  
Arun N. Kumar ◽  
R. John Leigh
Keyword(s):  
Eye Movements ◽  
Control Experiment ◽  
Human Subjects ◽  
Head Rotation ◽  
Contextual Cues ◽  
Motion Vision ◽  
Stationary Target ◽  
Vestibular Response ◽  
Geometric Relationship ◽  
Head Rotations

The gain of the human vestibuloocular reflex (VOR) is influenced by the proximity of the object of regard. In six human subjects, we measured the eye rotations induced by passive, sinusoidal, horizontal head rotations at 2.0 Hz during binocular fixation of a stationary far target at 7 m; a stationary target close to the subject's near point of fixation (<15 cm); and the bridge of the subject's own nose, viewed through a mirror positioned so that, for each subject, the angle of vergence was similar to that during viewing of the near target. The median gain of compensatory eye movements for the group of subjects during far viewing was 0.99 (range 0.80–1.04), during near viewing was 1.21 (range 0.88–1.47), and during mirror viewing was 0.85 (range 0.71–1.01). The gain during near and mirror viewing was significantly different for each subject ( P < 0.001) even though the vergence angles were similar. The lower gain values during mirror viewing can be attributed to the geometric relationship between the head rotation, the position of the eyes in the head, and the movement of the subject's virtual image in the mirror. To determine whether visually mediated eye movements were responsible for the observed gain values, we conducted a control experiment in which subjects were rotated using a sum-of-sines stimulus that minimized the effects of predictive visual tracking; differences of gain values between near- and mirror-viewing conditions were similar to those during rotation at 2 Hz. We conclude that, in these experiments, target proximity and vergence angle were not the key determinants of gain of the visuo-vestibular response during head rotation while viewing a near target but that contextual cues from motion vision were more important in generating the appropriate response.

scholarly journals Diagnostic accuracy of a smartphone bedside test to assess the fixation suppression of the vestibulo-ocular reflex: when nothing else matters

2020 ◽  
Vol 267 (7) ◽  
pp. 2159-2163
Author(s):  
Florin Gandor ◽  
Manfred Tesch ◽  
Hannelore Neuhauser ◽  
Doreen Gruber ◽  
Hans-Jochen Heinze ◽  
...  
Keyword(s):  
Eye Movements ◽  
Diagnostic Accuracy ◽  
Healthy Subjects ◽  
Healthy Controls ◽  
Rater Agreement ◽  
Cerebellar Syndrome ◽  
Ocular Reflex ◽  
Bedside Test ◽  
Vestibulo Ocular Reflex ◽  
Healthy Cohort

Abstract Objective Validation of a bedside test to objectify the fixation suppression of the vestibulo-ocular reflex (FS-VOR) in patients with a cerebellar syndrome and healthy controls. Methods The vestibulo-ocular reflex and its fixation suppression were assessed by video-nystagmography (VNG) in 20 healthy subjects (mean age 56 ± 15) and 19 patients with a cerebellar syndrome (mean age 70 ± 11). The statistical cutoff delineating normal from pathological FS-VOR was determined at the 2.5th percentile of the normal distribution of the healthy cohort. VNG was then compared to a bedside test, where eye movements were recorded with a smartphone while patients were rotated on a swivel chair at a defined speed and amplitude. These videos were rated as normal or pathological FS-VOR by six blinded raters, and results compared to VNG. Results VNG in healthy controls showed FS-VOR with a reduction of nystagmus beats by 95.0% ± 7.2 (mean ± SD). The statistical cutoff was set at 80.6%. Cerebellar patients reduced nystagmus beats by only 26.3% ± 25.1. Inter-rater agreement of the smartphone video ratings was 85%. The sensitivity of the video ratings to detect an impaired FS-VOR was 99%, its specificity 92%. Inter-test agreement was 91%. Conclusion The smartphone bedside test is an easily performed, reliable, sensitive, specific, and inexpensive alternative for assessing FS-VOR.

Asymmetry of Vestibulo-Ocular Reflex in the Cat

1985 ◽  
Vol 93 (5) ◽  
pp. 597-600 ◽  
Author(s):  
John H. Anderson ◽  
Stephen L. Liston
Keyword(s):  
Eye Movements ◽  
Semicircular Canals ◽  
Whole Body ◽  
Slow Phase ◽  
Ocular Reflex ◽  
Vestibulo Ocular Reflex ◽  
Vertical Semicircular Canals

Vertical eye movements were recorded in alert, restrained cats that were subjected to whole-body rotations which stimulated the vertical semicircular canals. The results showed a significant asymmetry between the upward and downward slow-phase eye movements, which suggests differences in the CNS processing of vertical canal inputs vis-à-vis the vestibulo-ocular reflex.

scholarly journals The Vestibulo-Auricular Reflex

2009 ◽  
Vol 101 (3) ◽  
pp. 1258-1266 ◽  
Author(s):  
Daniel J. Tollin ◽  
Janet L. Ruhland ◽  
Tom C. T. Yin
Keyword(s):  
Eye Movements ◽  
Orienting Response ◽  
Head Position ◽  
Efference Copy ◽  
Head Movements ◽  
Fixed Position ◽  
Gaze Shift ◽  
The Gaze ◽  
Ocular Reflex ◽  
Vestibulo Ocular Reflex

The mammalian orienting response to sounds consists of a gaze shift that can be a combination of head and eye movements. In animals with mobile pinnae, the ears also move. During head movements, vision is stabilized by compensatory rotations of the eyeball within the head because of the vestibulo-ocular reflex (VOR). While studying the gaze shifts made by cats to sounds, a previously uncharacterized compensatory movement was discovered. The pinnae exhibited short-latency, goal-directed movements that reached their target while the head was still moving. The pinnae maintained a fixed position in space by counter-rotating on the head with an equal but opposite velocity to the head movement. We call these compensatory ear movements the vestibulo-auricular reflex (VAR) because they shared many kinematic characteristics with the VOR. Control experiments ruled out efference copy of head position signals and acoustic tracking (audiokinetic) of the source as the cause of the response. The VAR may serve to stabilize the auditory world during head movements.

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