Importance of the vestibular system in visually induced nausea and self-vection

1999 ◽  
Vol 9 (2) ◽  
pp. 83-87 ◽  
Author(s):  
Walter H. Johnson ◽  
Fred A. Sunahara ◽  
Jack P. Landolt
Keyword(s):  
Eye Movements ◽  
Visual Field ◽  
Inner Ear ◽  
Vestibular System ◽  
Head Movement ◽  
Sensory Input ◽  
Visual Stimulation ◽  
Normal Subjects ◽  
Visual Input ◽  
Head Movements

The objective of this study was to determine the importance, if any, of the non-auditory labyrinth of the inner ear in visually induced nausea and self-vection in subjects exposed to a moving visual field with and without concomitant pitching head movements. Subjects teated were 15 normals, 18 unilateral labyrinthectomies and 6 bilateral labyrinthectomies. The findings show a higher incidence of pseudo-Coriolis induced nausea in normal subjects compared to unilateral and bilateral labyrinthectomized subjects. When the subjects were exposed to the moving visual field only (no head movement), pronounced self-vection occurred in all subjects, but with earlier onset in the bilateral labyrinthine defective subjects as compared to normal and unilateral defective subjects. The subjective intensities of self-vections reported by labyrinth-defectives were much more pronounced as compared to normal subjects, and it is apparent that visual input in these subjects achieves much more importance in maintaining compensatory eye movements, and the gain of neck reflexes is enhanced. The findings that visual stimulation is more effective in producing the disabling effects after labyrinthine destruction could possibly be explained by enhancement of vision after loss of labyrinthine sensory input, and the gain in neck reflexes is also enhanced after labyrinthectomy.

Lateral rectus muscle changes after bilateral neonatal labyrinthectomy in the ferret

2005 ◽  
Vol 15 (5-6) ◽  
pp. 243-251
Author(s):  
Mary S. Shall ◽  
Susan Van Cleave ◽  
Diana M. Dimitrova ◽  
Stephen J. Goldberg
Keyword(s):  
Eye Movements ◽  
Inner Ear ◽  
Muscle Fiber ◽  
Vestibular System ◽  
Muscle Fibers ◽  
Rectus Muscle ◽  
Head Movements ◽  
Lateral Rectus ◽  
Muscle Fiber Types ◽  
Fiber Types

The vestibular system is essential to the coordination of eye movements during head movements. Exercise, such as the eye movements mediated by the vestibular system, is a major factor in the development of muscle fiber types and the strength of muscle. In this study, the contents of the inner ear were removed (labyrinthectomy) from (LAB) ferrets at postnatal day 10 (P10) and raised with control (SHAM) animals. At P30, the lateral rectus muscles (LR) were removed to analyze the expression of myosin heavy chain (MHC) isoforms and to measure the least diameter of the developmental, slow and fast type muscle fibers. Another set of animals were sacrificed at P120 to analyze MHC isoform expression and muscle fiber diameters, as well as the contractile characteristics of the LR were measured prior to sacrifice. The average LAB LR was significantly stronger than the SHAM LR and the muscle fibers of the LAB animals were larger in diameter. The LAB animals expressed more type IIx and less slow type MHC. These results support the hypothesis that input from the inner ear influence the development of strength and muscle diameter in the ferret extraocular muscles.

scholarly journals Neural Basis of Visually Guided Head Movements Studied With fMRI

2003 ◽  
Vol 89 (5) ◽  
pp. 2516-2527 ◽  
Author(s):  
Laurent Petit ◽  
Michael S. Beauchamp
Keyword(s):  
Eye Movements ◽  
Head Movement ◽  
Brain Activity ◽  
Posterior Part ◽  
Vestibular Stimulation ◽  
Head Movements ◽  
Oculomotor Control ◽  
Imaging Studies ◽  
Neural Basis ◽  
Temporoparietal Junction

We used event-related fMRI to measure brain activity while subjects performed saccadic eye, head, and gaze movements to visually presented targets. Two distinct patterns of response were observed. One set of areas was equally active during eye, head, and gaze movements and consisted of the superior and inferior subdivisions of the frontal eye fields, the supplementary eye field, the intraparietal sulcus, the precuneus, area MT in the lateral occipital sulcus and subcortically in basal ganglia, thalamus, and the superior colliculus. These areas have been previously observed in functional imaging studies of human eye movements, suggesting that a common set of brain areas subserves both oculomotor and head movement control in humans, consistent with data from single-unit recording and microstimulation studies in nonhuman primates that have described overlapping eye- and head-movement representations in oculomotor control areas. A second set of areas was active during head and gaze movements but not during eye movements. This set of areas included the posterior part of the planum temporale and the cortex at the temporoparietal junction, known as the parieto-insular vestibular cortex (PIVC). Activity in PIVC has been observed during imaging studies of invasive vestibular stimulation, and we confirm its role in processing the vestibular cues accompanying natural head movements. Our findings demonstrate that fMRI can be used to study the neural basis of head movements and show that areas that control eye movements also control head movements. In addition, we provide the first evidence for brain activity associated with vestibular input produced by natural head movements as opposed to invasive caloric or galvanic vestibular stimulation.

Active head movements facilitate compensation for effects of prism displacement on dynamic gait12

2006 ◽  
Vol 16 (1-2) ◽  
pp. 29-33
Author(s):  
Kim R. Gottshall ◽  
Michael E. Hoffer ◽  
Helen S. Cohen ◽  
Robert J. Moore
Keyword(s):  
Head Movement ◽  
Sensory Modality ◽  
Normal Subjects ◽  
The Body ◽  
Head Movements ◽  
Head Motion ◽  
Control Group ◽  
Entire Body ◽  
Group 3 ◽  
Group 2

Study design: Four groups, between-subjects study. Objectives: To investigate the effects of exercise on adaptation of normal subjects who had been artificially spatially disoriented. Background: Many patients referred for rehabilitation experience sensory changes, due to age or disease processes, and these changes affect motor skill. The best way to train patients to adapt to these changes and to improve their sensorimotor skills is unclear. Using normal subjects, we tested the hypothesis that active, planned head movement is needed to adapt to modified visual input. Methods and measures: Eighty male and female subjects who had normal balance on computerized dynamic posturography (CDP) and the dynamic gait index (DGI), were randomly assigned to four groups. All groups donned diagonally shift lenses and were again assessed with CDP and DGI. The four groups were then treated for 20 min. Group 1 (control group) viewed a video, Group 2 performed exercise that involved translating the entire body through space, but without separate, volitional head movement, Group 3 performed exercises which all incorporated volitional, planned head rotations, and Group 4 performed exercises that involved translating the body (as in Group 2) and incorporated volitional, planned head motion (as in Group 3). All subjects were post-tested with CDP and DGI, lenses were removed, and subjects were retested again with CDP and DGI. Results: The groups did not differ significantly on CDP scores but Groups 3 and 4 had significantly better DGI scores than Groups 1 and 2. Conclusions: Active head movement that is specifically planned as part of the exercise is more effective than passive attention or head movements that are not consciously planned, for adapting to sensorimotor change when it incorporates active use of the changed sensory modality, in this case head motion.

Reading with Visual Field Defects

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 11-11 ◽  
Author(s):  
S Trauzettel-Klosinski
Keyword(s):  
Eye Movements ◽  
Visual Field ◽  
Reading Ability ◽  
Reading Speed ◽  
Visual Fields ◽  
Zero Point ◽  
Normal Subjects ◽  
Visual Field Defects ◽  
Video Tape ◽  
Field Defects

The influence of different visual field defects on the reading performance was examined with potential adaptive strategies to improve the reading process in mind. By means of an SLO, the retinal fixation locus (RFL) was determined with the use of single targets and text, and eye movements scanning the text were recorded on video tape. Additionally, eye movements were monitored by an Infrared Limbus Tracker. Visual fields were assessed by the Tübingen Manual and/or automatic perimetry. Normal subjects, and patients with central scotomata, ring scotomata, and hemianopic field defects (HFD) were examined. The main pathological reading parameters were an increase of saccade frequency and regressions per line, and a decrease of reading speed. In patients with field defects involving the visual field centre, fixation behaviour is significant for regaining reading ability. In absolute central scotoma, the lost foveal function promotes eccentric fixation. The remaining problem is insufficient resolution of the RFL, which can be compensated for by magnification of the text. In patients with insufficient size of their reading visual field, due to HFD and ring scotoma, it is crucial that they learn to use a new RFL despite intact foveolar function. Preconditions for reading have been found to be: (1) sufficient resolution of the RFL, (2) a reading visual field of a minimum extent, and (3) intact basic oculomotor function. In patients with visual field defects involving the centre, a sensory-motor adaptation process is required: the use of a new RFL as the new centre of the visual field and as the new zero point for eye-movement coordinates.

The Vestibular Sense

2017 ◽  
Author(s):  
Peggy Mason
Keyword(s):  
Inner Ear ◽  
Vestibular System ◽  
Alcohol Intoxication ◽  
Conscious Experience ◽  
Head Tilt ◽  
Angular Acceleration ◽  
Semicircular Canals ◽  
Linear Acceleration ◽  
Head Movements ◽  
Age Related

The vestibular system contains semicircular canals that respond to angular acceleration and otoconial organs that respond to linear acceleration of the head. Information is sent to the motor system and, under normal circumstances, does not lead to conscious perception. Yet damage to the vestibular system can result in disequilibrium or vertigo, disturbing perceptions that dominate conscious experience. The shared residence of the cochlear and vestibular end organs in the inner ear can give rise to inner ear disorders such as Ménière’s disease. The effect of gravity on the otoconial masses in the sacculus and utriculus enable detection of static head tilt. Age-related disequilibrium, benign paroxysmal positional vertigo, motion sickness, and alcohol intoxication–induced vertigo are explained. How natural head movements elicit combined canal and otoconial organ responses is described. Finally, the dependence of posture and gaze on vestibular inputs is introduced as a segue to the next chapter.

Eye-head coordination in cats

1984 ◽  
Vol 52 (6) ◽  
pp. 1030-1050 ◽  
Author(s):  
D. Guitton ◽  
R. M. Douglas ◽  
M. Volle
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Head Movement ◽  
Maximum Velocity ◽  
Head Movements ◽  
Visual Axis ◽  
Gaze Shifts ◽  
Gaze Shift ◽  
Rapid Eye Movements ◽  
Motor Strategy

Gaze is the position of the visual axis in space and is the sum of the eye movement relative to the head plus head movement relative to space. In monkeys, a gaze shift is programmed with a single saccade that will, by itself, take the eye to a target, irrespective of whether the head moves. If the head turns simultaneously, the saccade is correctly reduced in size (to prevent gaze overshoot) by the vestibuloocular reflex (VOR). Cats have an oculomotor range (OMR) of only about +/- 25 degrees, but their field of view extends to about +/- 70 degrees. The use of the monkey's motor strategy to acquire targets lying beyond +/- 25 degrees requires the programming of saccades that cannot be physically made. We have studied, in cats, rapid horizontal gaze shifts to visual targets within and beyond the OMR. Heads were either totally unrestrained or attached to an apparatus that permitted short unexpected perturbations of the head trajectory. Qualitatively, similar rapid gaze shifts of all sizes up to at least 70 degrees could be accomplished with the classic single-eye saccade and a saccade-like head movement. For gaze shifts greater than 30 degrees, this classic pattern frequently was not observed, and gaze shifts were accomplished with a series of rapid eye movements whose time separation decreased, frequently until they blended into each other, as head velocity increased. Between discrete rapid eye movements, gaze continued in constant velocity ramps, controlled by signals added to the VOR-induced compensatory phase that followed a saccade. When the head was braked just prior to its onset in a 10 degrees gaze shift, the eye attained the target. This motor strategy is the same as that reported for monkeys. However, for larger target eccentricities (e.g., 50 degrees), the gaze shift was interrupted by the brake and the average saccade amplitude was 12-15 degrees, well short of the target and the OMR. Gaze shifts were completed by vestibularly driven eye movements when the head was released. Braking the head during either quick phases driven by passive head displacements or visually triggered saccades resulted in an acceleration of the eye, thereby implying interaction between the VOR and these rapid-eye-movement signals. Head movements possessed a characteristic but task-dependent relationship between maximum velocity and amplitude. Head movements terminated with the head on target. The eye saccade usually lagged the head displacement.(ABSTRACT TRUNCATED AT 400 WORDS)

Eye-head coordination in darkness: Formulation and testing of a mathematical model

2003 ◽  
Vol 13 (2-3) ◽  
pp. 79-91
Author(s):  
Stefano Ramat ◽  
Roberto Schmid ◽  
Daniela Zambarbieri
Keyword(s):  
Mathematical Model ◽  
Vestibular System ◽  
Sensory Information ◽  
Head Rotation ◽  
Normal Subjects ◽  
Head Movements ◽  
Vestibular Nystagmus ◽  
Ocular Reflex ◽  
Head Displacement ◽  
Vestibulo Ocular Reflex

Passive head rotation in darkness produces vestibular nystagmus, consisting of slow and quick phases. The vestibulo-ocular reflex produces the slow phases, in the compensatory direction, while the fast phases, in the same direction as head rotation, are of saccadic origin. We have investigated how the saccadic components of the ocular motor responses evoked by active head rotation in darkness are generated, assuming the only available sensory information is that provided by the vestibular system. We recorded the eye and head movements of nine normal subjects during active head rotation in darkness. Subjects were instructed to rotate their heads in a sinusoidal-like manner and to focus their attention on producing a smooth head rotation. We found that the desired eye position signal provided to the saccadic mechanism by the vestibular system may be modeled as a linear combination of head velocity and head displacement information. Here we present a mathematical model for the generation of both the slow and quick phases of vestibular nystagmus based on our findings. Simulations of this model accurately fit experimental data recorded from subjects.

Sensorimotor serial dependencies in head movements

2021 ◽  
Author(s):  
Eckart Zimmermann
Keyword(s):  
Eye Movements ◽  
Head Movement ◽  
Target Location ◽  
Real Life ◽  
Head Movements ◽  
Visual Localization ◽  
Target Displacement ◽  
Gaze Shifts ◽  
Movement Accuracy ◽  
Head Mounted Display

On average, we redirect our gaze with a frequency at about 3 Hz. In real life, gaze shifts consist of eye and head movements. Much research has focused on how the accuracy of eye movements is monitored and calibrated. By contrast, little is known about how head movements remain accurate. I wondered whether serial dependencies between artificially induced errors in head movement targeting and the immediately following head movement might recalibrate movement accuracy. I also asked whether head movement targeting errors would influence visual localization. To this end, participants wore a head mounted display and performed head movements to targets, which were displaced as soon as the start of the head movement was detected. I found that target displacements influenced head movement amplitudes in the same trial, indicating that participants could adjust their movement online to reach the new target location. However, I also found serial dependencies between the target displacement in trial n-1 and head movements amplitudes in the following trial n. I did not find serial dependencies between target displacements and visuomotor localization. The results reveal that serial dependencies recalibrate head movement accuracy.

Visual-Vestibular Interaction with Telescopic Spectacles

1991 ◽  
Vol 1 (3) ◽  
pp. 263-277 ◽  
Author(s):  
J.L. Demer ◽  
J. Goldberg ◽  
F.I. Porter ◽  
H.A. Jenkins ◽  
K. Schmidt
Keyword(s):  
Eye Movements ◽  
Retinal Image ◽  
Head Rotation ◽  
Normal Subjects ◽  
Head Movements ◽  
Head Velocity ◽  
Ocular Reflex ◽  
Clear Vision ◽  
Visual Vestibular Interaction ◽  
Vestibulo Ocular Reflex

Vestibularly and visually driven eye movements interact to compensate for head movements to maintain the necessary retinal image stability for clear vision. The wearing of highly magnifying telescopic spectacles requires that such compensatory visual-vestibular interaction operate in a quantitative regime much more demanding than that normally encountered. We employed electro-oculography to investigate the effect of wearing of 2×, 4×, and 6× binocular telescopic spectacles on visual-vestibular interactions during sinusoidal head rotation in 43 normal subjects. All telescopic spectacle powers produced a large, immediate increase in the gain (eye velocity/head velocity) of compensatory eye movements, called the visual-vestibulo-ocular reflex (VVOR). However, the amount of VVOR gain augmentation became limited as spectacle magnification and the amplitude of head velocity increased. Optokinetic responses during wearing of telescopic spectacles exhibited a similar nonlinearity with respect to stimulus amplitude and spectacle magnification. Computer simulation was used to demonstrate that the nonlinear response of the VVOR with telescopic spectacles is a result of nonlinearities in visually guided tracking movements. Immediate augmentation of VVOR gain by telescopic spectacles declined significantly with increasing age in the subject pool studied. Presentation of unmagnified visual field peripheral to the telescopic spectacles reduced the immediate VVOR gain-enhancing effect of central magnified vision. These results imply that the VVOR may not be adequate to maintain retinal image stability during head movements when strongly magnifying telescopic spectacles are worn.

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