Microgravity Vestibular Investigations: Perception of Self-Orientation and Self-Motion

1997 ◽  
Vol 7 (6) ◽  
pp. 453-457
Author(s):  
Alan J. Benson ◽  
Fred E. Guedry ◽  
Donald E. Parker ◽  
Millard F. Reschke
Keyword(s):  
Constant Velocity ◽  
Sensory Information ◽  
Whole Body ◽  
Body Rotation ◽  
Dependent Vector ◽  
Perception Of Self ◽  
Axis Rotation ◽  
Otolith System ◽  
Self Motion ◽  
Orbital Mission

Four astronauts experienced passive whole-body rotation in a number of test sessions during a 7-day orbital mission. Pitch (Y-axis) and roll (X-axis) rotation required subject orientations on the rotator in which the otolith system was at radius of 0.5 m. Thus subjects experienced a constant -0.22 Gz stimulus to the otoliths during the 60 s constant-velocity segments of “pitch” and “roll” ramp profiles. The Gz stimulus, a radius-dependent vector ranging from -0.22 Gz at the otoliths to +0.36 Gz at the feet, generated sensory information that was not interpreted as inversion in any of the 16 tests carried out in flight (12 in pitch and 4 in roll orientation). None of the subjects was rotated with head off-center during the first 33 h of the mission. In the state of orbital adaptation of these subjects, a -0.22 Gz otolith stimulus did not provide a vertical reference in the presence of a gradient of -Gz stimuli to the trunk and legs.

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.

scholarly journals Biases in the perception of self-motion during whole-body acceleration and deceleration

2013 ◽  
Vol 7 ◽  
Author(s):  
Luc Tremblay ◽  
Andrew Kennedy ◽  
Dany Paleressompoulle ◽  
Liliane Borel ◽  
Laurence Mouchnino ◽  
...  
Keyword(s):  
Whole Body ◽  
Body Acceleration ◽  
Acceleration And Deceleration ◽  
Perception Of Self ◽  
Self Motion

Multisensory Integration and the Perception of Self-Motion

2018 ◽  
Author(s):  
Kathleen E. Cullen
Keyword(s):  
Rotational Velocity ◽  
Sensory Information ◽  
Proprioceptive Information ◽  
Everyday Activities ◽  
Perceptual Stability ◽  
The World ◽  
Perception Of Self ◽  
Self Motion ◽  
The Brain ◽  
Vestibular Pathways

As we go about our everyday activities, our brain computes accurate estimates of both our motion relative to the world, and of our orientation relative to gravity. Essential to this computation is the information provided by the vestibular system; it detects the rotational velocity and linear acceleration of our heads relative to space, making a fundamental contribution to our perception of self-motion and spatial orientation. Additionally, in everyday life, our perception of self-motion depends on the integration of both vestibular and nonvestibular cues, including visual and proprioceptive information. Furthermore, the integration of motor-related information is also required for perceptual stability, so that the brain can distinguish whether the experienced sensory inflow was a result of active self-motion through the world or if instead self-motion that was externally generated. To date, understanding how the brain encodes and integrates sensory cues with motor signals for the perception of self-motion during natural behaviors remains a major goal in neuroscience. Recent experiments have (i) provided new insights into the neural code used to represent sensory information in vestibular pathways, (ii) established that vestibular pathways are inherently multimodal at the earliest stages of processing, and (iii) revealed that self-motion information processing is adjusted to meet the needs of specific tasks. Our current level of understanding of how the brain integrates sensory information and motor-related signals to encode self-motion and ensure perceptual stability during everyday activities is reviewed.

scholarly journals Therapy-Resistant Atypical Downbeat Nystagmus with Vertigo Confined to Specific Head-Hanging Positions: Mapping to the Gravity Vector on a Multi-Axis Turntable

2021 ◽  
pp. 464-469
Author(s):  
Dominik Péus ◽  
Dominik Straumann ◽  
Alexander Huber ◽  
Christopher J. Bockisch ◽  
Vincent Wettstein
Keyword(s):  
Hair Cells ◽  
Whole Body ◽  
Downbeat Nystagmus ◽  
Two Dimensional ◽  
Body Rotation ◽  
Therapeutic Approaches ◽  
Atypical Case ◽  
Anterior Semicircular Canal ◽  
Head Positions ◽  
Peripheral Origin

Downbeat nystagmus (DBN) observed in head-hanging positions, may be of central or peripheral origin. Central DBN in head-hanging positions is mostly due to a disorder of the vestibulo-cerebellum, whereas peripheral DBN is usually attributed to canalolithiasis of an anterior semicircular canal. Here, we describe an atypical case of a patient who, after head trauma, experienced severe and stereotypic vertigo attacks after being placed in various head-hanging positions. Vertigo lasted 10–15 s and was always associated with a robust DBN. The provocation of transient vertigo and DBN, which both showed no decrease upon repetition of maneuvers, depended on the yaw orientation relative to the trunk and the angle of backward pitch. On a motorized, multi-axis turntable, we identified the two-dimensional Helmholtz coordinates of head positions at which vertigo and DBN occurred (<i>y</i>-axis: horizontal, space-fixed; <i>z</i>-axis: vertical, and head-fixed; <i>x</i>-axis: torsional, head-fixed, and unchanged). This two-dimensional area of DBN-associated head positions did not change when whole-body rotations took different paths (e.g., by forwarding pitch) or were executed with different velocities. Moreover, the intensity of DBN was also independent of whole-body rotation paths and velocities. So far, therapeutic approaches with repeated liberation maneuvers and cranial vibrations were not successful. We speculate that vertigo and DBN in this patient are due to macular damage, possibly an unstable otolithic membrane that, in specific orientations relative to gravity, slips into a position causing paroxysmal stimulation or inhibition of macular hair cells.

Disruption of self-motion perception without vestibular reflex alteration in ménière’s disease

2021 ◽  
pp. 1-11
Author(s):  
Mario Faralli ◽  
Michele Ori ◽  
Giampietro Ricci ◽  
Mauro Roscini ◽  
Roberto Panichi ◽  
...  
Keyword(s):  
Motion Perception ◽  
Meniere’S Disease ◽  
Menière’S Disease ◽  
Whole Body ◽  
Meniere's Disease ◽  
Ménière’S Disease ◽  
Menière's Disease ◽  
Ocular Reflex ◽  
Ménière's Disease ◽  
Self Motion

BACKGROUND: Self-motion misperception has been observed in vestibular patients during asymmetric body oscillations. This misperception is correlated with the patient’s vestibular discomfort. OBJECTIVE: To investigate whether or not self-motion misperception persists in post-ictal patients with Ménière’s disease (MD). METHODS: Twenty-eight MD patients were investigated while in the post-ictal interval. Self-motion perception was studied by examining the displacement of a memorized visual target after sequences of opposite directed fast-slow asymmetric whole body rotations in the dark. The difference in target representation was analyzed and correlated with the Dizziness Handicap Inventory (DHI) score. The vestibulo-ocular reflex (VOR) and clinical tests for ocular reflex were also evaluated. RESULTS: All MD patients showed a noticeable difference in target representation after asymmetric rotation depending on the direction of the fast/slow rotations. This side difference suggests disruption of motion perception. The DHI score was correlated with the amount of motion misperception. In contrast, VOR and clinical trials were altered in only half of these patients. CONCLUSIONS: Asymmetric rotation reveals disruption of self-motion perception in MD patients during the post-ictal interval, even in the absence of ocular reflex impairment. Motion misperception may cause persistent vestibular discomfort in these patients.

Torsional eye movements are facilitated during perception of self-motion

1999 ◽  
Vol 126 (4) ◽  
pp. 495-500 ◽  
Author(s):  
K. V. Thilo ◽  
Thomas Probst ◽  
Adolfo M. Bronstein ◽  
Yatsuji Ito ◽  
Michael A. Gresty
Keyword(s):  
Eye Movements ◽  
Perception Of Self ◽  
Self Motion

scholarly journals Antihysteresis of perceived longitudinal body axis during continuous quasi-static whole-body rotation in the earth-vertical roll plane

2011 ◽  
Vol 209 (3) ◽  
pp. 443-454
Author(s):  
M. Tatalias ◽  
C. J. Bockisch ◽  
G. Bertolini ◽  
D. Straumann ◽  
A. Palla
Keyword(s):  
Body Axis ◽  
Whole Body ◽  
Body Rotation ◽  
Longitudinal Body Axis ◽  
Vertical Roll ◽  
The Earth

How to use body tilt for the simulation of linear self motion

2004 ◽  
Vol 14 (5) ◽  
pp. 375-385 ◽  
Author(s):  
E.L. Groen ◽  
W. Bles
Keyword(s):  
Visual Motion ◽  
Detection Threshold ◽  
Stimulus Frequency ◽  
Flight Simulation ◽  
Body Tilt ◽  
Whole Body ◽  
Motion Percept ◽  
Self Motion ◽  
Rate Limit ◽  
Pitch Tilt

We examined to what extent body tilt may augment the perception of visually simulated linear self acceleration. Fourteen subjects judged visual motion profiles of fore-aft motion at four different frequencies between 0.04âĂŞ0.33 Hz, and at three different acceleration amplitudes (0.44, 0.88 and 1.76 m / s 2 ). Simultaneously, subjects were tilted backward and forward about their pitch axis. The amplitude of pitch tilt was systematically varied. Using a two-alternative-forced-choice paradigm, psychometric curves were calculated in order to determine: 1) the minimum tilt amplitude required to generate a linear self-motion percept in more than 50% of the cases, and 2) the maximum tilt amplitude at which rotation remains sub-threshold in more than 50% of the cases. The results showed that the simulation of linear self motion became more realistic with the application of whole body tilt, as long as the tilt rate remained under the detection threshold of about 3 deg/s. This value is in close agreement with the empirical rate limit commonly used in flight simulation. The minimum required motion cue was inversely proportional to stimulus frequency, and increased with the amplitude of the visual displacement (rather than acceleration). As a consequence, the range of useful tilt stimuli became more critical with increasing stimulus frequency. We conclude that this psychophysical approach reveals valid parameters for motion driving algorithms used in motion base simulators.

Vestibulo-ocular function in anxiety disorders

2007 ◽  
Vol 16 (4-5) ◽  
pp. 209-215
Author(s):  
Joseph M. Furman ◽  
Mark S. Redfern ◽  
Rolf G. Jacob
Keyword(s):  
Panic Disorder ◽  
Anxiety Disorders ◽  
Semicircular Canal ◽  
Constant Velocity ◽  
Vertical Axis ◽  
Velocity Storage ◽  
Movement Response ◽  
Ocular Reflex ◽  
Axis Rotation ◽  
High Degree

Previous studies of vestibulo-ocular function in patients with anxiety disorders have suggested a higher prevalence of peripheral vestibular dysfunction compared to control populations, especially in panic disorder with agoraphobia. Also, our recent companion studies have indicated abnormalities in postural control in patients with anxiety disorders who report a high degree of space and motion discomfort. The aim of the present study was to assess the VOR, including the semicircular canal-ocular reflex, the otolith-ocular reflex, and semicircular canal-otolith interaction, in a well-defined group of patients with anxiety disorders. The study included 72 patients with anxiety disorders (age 30.6 +/− 10.6 yrs; 60 (83.3% F) and 29 psychiatrically normal controls (age 35.0 +/minus; 11.6 yrs; 24 (82.8% F). 25 patients had panic disorder; 47 patients had non-panic anxiety. Patients were further categorized based on the presence (45 of 72) or absence (27 of 72) of height phobia and the presence (27 of 72) or absence (45 of 72) of excessive space and motion discomfort (SMD). Sinusoidal and constant velocity earth-vertical axis rotation (EVAR) was used to assess the semicircular canal-ocular reflex. Constant velocity off-vertical axis rotation (OVAR) was used to assess both the otolith-ocular reflex and static semicircular canal-otolith interaction. Sinusoidal OVAR was used to assess dynamic semicircular canal-otolith interaction. The eye movement response to rotation was measured using bitemporal electro-oculography. Results showed a significantly higher VOR gain and a significantly shorter VOR time constant in anxiety patients. The effect of anxiety on VOR gain was significantly greater in patients without SMD as compared to those with SMD. Anxiety patients without height phobia had a larger OVAR modulation. We postulate that in patients with anxiety, there is increased vestibular sensitivity and impaired velocity storage. Excessive SMD and height phobia seem to have a mitigating effect on abnormal vestibular sensitivity, possibly via a down-weighting of central vestibular pathways.

scholarly journals Population Coding of Self-Motion: Applying Bayesian Analysis to a Population of Visual Interneurons in the Fly

2005 ◽  
Vol 94 (3) ◽  
pp. 2182-2194 ◽  
Author(s):  
Katja Karmeier ◽  
Holger G. Krapp ◽  
Martin Egelhaaf
Keyword(s):  
Bayesian Analysis ◽  
Rotation Axis ◽  
Sensory Information ◽  
Population Coding ◽  
Calliphora Vicina ◽  
Integration Time ◽  
Noise Correlation ◽  
Neuronal Populations ◽  
Response Onset ◽  
Self Motion

Coding of sensory information often involves the activity of neuronal populations. We demonstrate how the accuracy of a population code depends on integration time, the size of the population, and noise correlation between the participating neurons. The population we study consists of 10 identified visual interneurons in the blowfly Calliphora vicina involved in optic flow processing. These neurons are assumed to encode the animal's head or body rotations around horizontal axes by means of graded potential changes. From electrophysiological experiments we obtain parameters for modeling the neurons' responses. From applying a Bayesian analysis on the modeled population response we draw three major conclusions. First, integration of neuronal activities over a time period of only 5 ms after response onset is sufficient to decode accurately the rotation axis. Second, noise correlation between neurons has only little impact on the population's performance. And third, although a population of only two neurons would be sufficient to encode any horizontal rotation axis, the population of 10 vertical system neurons is advantageous if the available integration time is short. For the fly, short integration times to decode neuronal responses are important when controlling rapid flight maneuvers.

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