“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.

scholarly journals Loss of α-9 Nicotinic Acetylcholine Receptor Subunit Predominantly Results in Impaired Postural Stability Rather Than Gaze Stability

2022 ◽  
Vol 15 ◽  
Author(s):  
Hui Ho Vanessa Chang ◽  
Barbara J. Morley ◽  
Kathleen E. Cullen
Keyword(s):  
Acetylcholine Receptor ◽  
Nicotinic Acetylcholine Receptor ◽  
Microelectromechanical Systems ◽  
Vestibular Function ◽  
Head Movements ◽  
Wild Type ◽  
Nicotinic Acetylcholine ◽  
Optokinetic Reflex ◽  
Gaze Stability ◽  
Vestibulo Ocular Reflex

The functional role of the mammalian efferent vestibular system (EVS) is not fully understood. One proposal is that the mammalian EVS plays a role in the long-term calibration of central vestibular pathways, for example during development. Here to test this possibility, we studied vestibular function in mice lacking a functional α9 subunit of the nicotinic acetylcholine receptor (nAChR) gene family, which mediates efferent activation of the vestibular periphery. We focused on an α9 (−/−) model with a deletion in exons 1 and 2. First, we quantified gaze stability by testing vestibulo-ocular reflex (VOR, 0.2–3 Hz) responses of both α9 (−/−) mouse models in dark and light conditions. VOR gains and phases were comparable for both α9 (−/−) mutants and wild-type controls. Second, we confirmed the lack of an effect from the α9 (−/−) mutation on central visuo-motor pathways/eye movement pathways via analyses of the optokinetic reflex (OKR) and quick phases of the VOR. We found no differences between α9 (−/−) mutants and wild-type controls. Third and finally, we investigated postural abilities during instrumented rotarod and balance beam tasks. Head movements were quantified using a 6D microelectromechanical systems (MEMS) module fixed to the mouse’s head. Compared to wild-type controls, we found head movements were strikingly altered in α9 (−/−) mice, most notably in the pitch axis. We confirmed these later results in another α9 (−/−) model, with a deletion in the exon 4 region. Overall, we conclude that the absence of the α9 subunit of nAChRs predominately results in an impairment of posture rather than gaze.

Vestibular Function and Motion Sickness Susceptibility: Videonystagmographic Evidence From Oculomotor and Caloric Tests

2020 ◽  
Vol 29 (2) ◽  
pp. 188-198
Author(s):  
Cynthia G. Fowler ◽  
Margaret Dallapiazza ◽  
Kathleen Talbot Hadsell
Keyword(s):  
Phase Velocity ◽  
Motion Sickness ◽  
Repeated Measures ◽  
Short Form ◽  
Vestibular Function ◽  
Slow Phase ◽  
Test Results ◽  
Normal Range ◽  
Slow Phase Velocity ◽  
Caloric Tests

Purpose Motion sickness (MS) is a common condition that affects millions of individuals. Although the condition is common and can be debilitating, little research has focused on the vestibular function associated with susceptibility to MS. One causal theory of MS is an asymmetry of vestibular function within or between ears. The purposes of this study, therefore, were (a) to determine if the vestibular system (oculomotor and caloric tests) in videonystagmography (VNG) is associated with susceptibility to MS and (b) to determine if these tests support the theory of an asymmetry between ears associated with MS susceptibility. Method VNG was used to measure oculomotor and caloric responses. Fifty young adults were recruited; 50 completed the oculomotor tests, and 31 completed the four caloric irrigations. MS susceptibility was evaluated with the Motion Sickness Susceptibility Questionnaire–Short Form; in this study, percent susceptibility ranged from 0% to 100% in the participants. Participants were divided into three susceptibility groups (Low, Mid, and High). Repeated-measures analyses of variance and pairwise comparisons determined significance among the groups on the VNG test results. Results Oculomotor test results revealed no significant differences among the MS susceptibility groups. Caloric stimuli elicited responses that were correlated positively with susceptibility to MS. Slow-phase velocity was slowest in the Low MS group compared to the Mid and High groups. There was no significant asymmetry between ears in any of the groups. Conclusions MS susceptibility was significantly and positively correlated with caloric slow-phase velocity. Although asymmetries between ears are purported to be associated with MS, asymmetries were not evident. Susceptibility to MS may contribute to interindividual variability of caloric responses within the normal range.

scholarly journals COMPARATIVE MEASUREMENTS OF HEAD ANGULAR MOVEMENTS USING A CAMERA SYSTEM AND A GYROSCOPE SYSTEM

2014 ◽  
Vol 54 (4) ◽  
pp. 295-300 ◽  
Author(s):  
Vladimir Socha ◽  
Patrik Kutilek ◽  
Ondrej Cakrt ◽  
Rudolf Cerny
Keyword(s):  
Head Movements ◽  
Head Orientation ◽  
Quiet Stance ◽  
Body Segment ◽  
Mean Velocity ◽  
Camera System ◽  
Rehabilitation Process ◽  
Gyroscope System ◽  
The Mean ◽  
2D Data

Assessments of body-segment angular movements are very important in the rehabilitation process. Head angular movements are measured and analyzed for use in studies of stability and posture. However, there is no methodology for assessing angular movements of the head, and it has not been verified whether data measured by fundamentally different MoCap systems will lead to the same results. In this study, we used a camera system and a 3DOF orientation tracker placed on the subject’s head, and measured inclination (roll) and flexion (pitch) during quiet stance. The total length and the mean velocity of the traces of the pitch versus roll plots were used to measure and analyze head orientation. Using these methods, we are able to model the distribution of the measured 2D data, and to evaluate stability and posture. The results show that the total lengths and the mean velocities related to the 3DOF orientation tracker do not differ significantly from the total lengths and the mean velocities of traces related to the IR medical camera. We also found that the systems are not interchangeable, and that the same type of system must be used each time. The designed methods can be used for studies not only of head movements but also of movements of other segments of the human body, and can be used to compare other types of MoCap systems, depending on the requirements for a specific rehabilitation examination.

scholarly journals Directional preference of otolith-related neurons in vestibular nucleus

2020 ◽  
Author(s):  
Nguyen Nguyen ◽  
Kyu-Sung Kim ◽  
Gyutae Kim
Keyword(s):  
Vestibular Nucleus ◽  
Vestibular Function ◽  
Semicircular Canals ◽  
Head Rotation ◽  
Head Movements ◽  
Neuronal Responses ◽  
Neural Communication ◽  
Neural Information ◽  
Commissural Pathway ◽  
Directional Preference

Abstract Background: Due to the paired structure of two labyrinths, their neural communication is conducted through the interconnected commissural pathway. Using the tight link, the neural responding characteristics are formed in vestibular nucleus, and these responses are initially generated by the mechanical movement of the hair cells in the semicircular canals and otoliths. Although the mechanism to describe the neuronal responses to the head movements was evident, few direct experimental data were provided, especially the directional preference of otolith-related neurons as one of critical responses to elucidate the function of the neurons in vestibular nucleus (VN). Experimental Approach: The directional preference of otolith-related neurons was investigated in VN. Also, a chemically induced unilateral labyrinthectomy (UL) was performed to identify the origin of the directional preference. For the model evaluation, static and dynamic behavioral tests were performed. Following the evaluation, an extracellular neural activity was recorded for the neuronal responses to the horizontal head rotation and the linear head translation. Results: Seventy seven neuronal activities were recorded from thirty SD rats (270-450 g, male), and total population was divided into three groups; left UL (20), sham (35), right UL (22). Based on the directional preference, two sub-groups were again classified as contra- and ipsi-preferred neurons. There was no significance in the number of those sub-groups (contra-: 15/35, 43%; ipsi-: 20/35, 57%) in the sham (p=0.155). However, more ipsi-preferred neurons (19/22, 86%) were observed after right UL (p=6.056×10-5) while left UL caused more contra-preferred neurons (13/20, 65%) (p=0.058). In particular, the convergent neurons mainly led this biased difference in the population (ipsi-: 100% after right UL & contra-: 89% after left UL) (p<0.002). Conclusion: The directional preference was evenly maintained under a normal vestibular function, and its unilateral loss biased the directional preference of the neurons, depending on the side of lesion. Moreover, the dominance of the directional preference was mainly led by the convergent neurons which had the neural information related with head rotation and linear translation.

scholarly journals Automated Analysis of Body Movement in Emotionally Expressive Piano Performances

2008 ◽  
Vol 26 (2) ◽  
pp. 103-119 ◽  
Author(s):  
Ginevra Castellano ◽  
Marcello Mortillaro ◽  
Antonio Camurri ◽  
Gualtiero Volpe ◽  
Klaus Scherer
Keyword(s):  
Emotional Expression ◽  
Temporal Dynamics ◽  
Body Movement ◽  
Music Performance ◽  
The Body ◽  
Head Movements ◽  
Automated System ◽  
Upper Body ◽  
Musical Score ◽  
Motion Cues

EMOTIONAL EXPRESSION IN MUSIC PERFORMANCE includes important cues arising from the body movement of the musician. This movement is related to both the musical score execution and the emotional intention conveyed. In this experiment, a pianist was asked to play the same excerpt with different emotionally expressive intentions. The aim was to verify whether different expressions could be distinguished based on movement by trying to determine which motion cues were most emotion-sensitive. Analyses were performed via an automated system capable of detecting the temporal profiles of two motion cues: the quantity of motion of the upper body and the velocity of head movements. Results showed that both were sensitive to emotional expression, especially the velocity of head movements. Further, some features conveying information about movement temporal dynamics varied among expressive conditions allowing emotion discrimination. These results are in line with recent theories that underlie the dynamic nature of emotional expression.

Normal Vestibular Function in Chicks After Partial Exposure to Microgravity During Development

1995 ◽  
Vol 5 (4) ◽  
pp. 289-298
Author(s):  
R.V. Kenyon ◽  
R. Kerschmann ◽  
R. Sgarioto ◽  
S. Jun ◽  
J. Vellinger
Keyword(s):  
Vestibular Function ◽  
Head Movements ◽  
Behavioral Changes ◽  
Ground Control ◽  
Consistent Difference ◽  
Morphological Examination ◽  
Behavioral Studies ◽  
Temporal Bones ◽  
Critical Developmental Period ◽  
Chicken Eggs

Sixty-four fertilized chicken eggs, half at developmental Day 2 and half at Day 9, were exposed to micro-gravity for 5 days aboard the shuttle. Postflight examination showed that none of the Day 2 flight embryos had survived, whereas the Day 9 flight group and both groups of synchronous ground control embryos appeared viable. One-half of the Day 9 flight and ground control embryos were dissected and the temporal bones preserved in acetone for morphological examination. The other half was allowed to hatch to examine vestibularly related behavioral changes. Morphology of the lagenar otoconia was evaluated by scanning electron microscopy. Behavioral changes were accessed by a battery of reflex tests and recordings of spontaneous and vestibularly driven head movements. The results from both the morphological and behavioral studies showed no consistent difference between the flight and the control animals. Several hypotheses may account for this negative result. Because all the Day 2 embryos failed to survive, the remaining Day 9 chicks may have passed the critical developmental period of the chick’s vestibular system. Also, the reexposure of the developing chick embryo to earth’s 1-g environment may have masked any adverse behavioral effects that exposure to Microgravity may have caused.

Vestibular habituation during repetitive complex stimulation: a study of transfer effects

1964 ◽  
Vol 19 (5) ◽  
pp. 1005-1015 ◽  
Author(s):  
Fred E. Guedry ◽  
William E. Collins ◽  
Ashton Graybiel
Keyword(s):  
Vestibular Function ◽  
Frontal Plane ◽  
Vestibular Stimulation ◽  
Head Movements ◽  
Residual Effects ◽  
Slow Rotation ◽  
Transfer Effects ◽  
Center Of Rotation ◽  
Static Tests ◽  
Rotation Direction

Thirty-two men were rotated at 7.5 rev/min while facing the center of the Pensacola slow rotation room for several hours. The men were seated 4 ft from the center of rotation; direction of rotation was toward the subject's left. During rotation, subjects were immobile except for series of measured head movements restricted to the frontal plane and to a particular quadrant of that plane for each subject. Nystagmus, illusory phenomena, and nausea were reduced by this procedure, but this habituation did not transfer to other forms of vestibular stimulation including that induced by head movements in an “unpracticed” quadrant of the same plane. Residual effects exhibited in “static tests” after the habituation program were primarily restricted to the practiced quadrant. habituation; nystagmus; vestibular function Submitted on January 15, 1964

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