scholarly journals Gravity dependence of the effect of optokinetic stimulation on the subjective visual vertical

2017 ◽  
Vol 117 (5) ◽  
pp. 1948-1958 ◽  
Author(s):  
Bryan K. Ward ◽  
Christopher J. Bockisch ◽  
Nicoletta Caramia ◽  
Giovanni Bertolini ◽  
Alexander Andrea Tarnutzer
Keyword(s):  
Bayesian Theory ◽  
Roll Angle ◽  
Whole Body ◽  
Optokinetic Stimulation ◽  
Subjective Visual Vertical ◽  
Vestibular Input ◽  
Stimulus Velocity ◽  
Visual Vertical ◽  
Observer Model ◽  
Roll Tilt

Accurate and precise estimates of direction of gravity are essential for spatial orientation. According to Bayesian theory, multisensory vestibular, visual, and proprioceptive input is centrally integrated in a weighted fashion based on the reliability of the component sensory signals. For otolithic input, a decreasing signal-to-noise ratio was demonstrated with increasing roll angle. We hypothesized that the weights of vestibular (otolithic) and extravestibular (visual/proprioceptive) sensors are roll-angle dependent and predicted an increased weight of extravestibular cues with increasing roll angle, potentially following the Bayesian hypothesis. To probe this concept, the subjective visual vertical (SVV) was assessed in different roll positions (≤ ± 120°, steps = 30°, n = 10) with/without presenting an optokinetic stimulus (velocity = ± 60°/s). The optokinetic stimulus biased the SVV toward the direction of stimulus rotation for roll angles ≥ ± 30° ( P < 0.005). Offsets grew from 3.9 ± 1.8° (upright) to 22.1 ± 11.8° (±120° roll tilt, P < 0.001). Trial-to-trial variability increased with roll angle, demonstrating a nonsignificant increase when providing optokinetic stimulation. Variability and optokinetic bias were correlated ( R2 = 0.71, slope = 0.71, 95% confidence interval = 0.57–0.86). An optimal-observer model combining an optokinetic bias with vestibular input reproduced measured errors closely. These findings support the hypothesis of a weighted multisensory integration when estimating direction of gravity with optokinetic stimulation. Visual input was weighted more when vestibular input became less reliable, i.e., at larger roll-tilt angles. However, according to Bayesian theory, the variability of combined cues is always lower than the variability of each source cue. If the observed increase in variability, although nonsignificant, is true, either it must depend on an additional source of variability, added after SVV computation, or it would conflict with the Bayesian hypothesis. NEW & NOTEWORTHY Applying a rotating optokinetic stimulus while recording the subjective visual vertical in different whole body roll angles, we noted the optokinetic-induced bias to correlate with the roll angle. These findings allow the hypothesis that the established optimal weighting of single-sensory cues depending on their reliability to estimate direction of gravity could be extended to a bias caused by visual self-motion stimuli.

Body-Tilt and Visual Verticality Perception During Multiple Cycles of Roll Rotation

2008 ◽  
Vol 99 (5) ◽  
pp. 2264-2280 ◽  
Author(s):  
R.A.A. Vingerhoets ◽  
W. P. Medendorp ◽  
J.A.M. Van Gisbergen
Keyword(s):  
Constant Velocity ◽  
Interaction Model ◽  
The Body ◽  
Body Tilt ◽  
Subjective Visual Vertical ◽  
Egocentric Bias ◽  
Leaky Integrator ◽  
Visual Vertical ◽  
Multiple Cycles ◽  
Roll Tilt

To assess the effects of degrading canal cues for dynamic spatial orientation in human observers, we tested how judgments about visual-line orientation in space (subjective visual vertical task, SVV) and estimates of instantaneous body tilt (subjective body-tilt task, SBT) develop in the course of three cycles of constant-velocity roll rotation. These abilities were tested across the entire tilt range in separate experiments. For comparison, we also obtained SVV data during static roll tilt. We found that as tilt increased, dynamic SVV responses became strongly biased toward the head pole of the body axis (A-effect), as if body tilt was underestimated. However, on entering the range of near-inverse tilts, SVV responses adopted a bimodal pattern, alternating between A-effects (biased toward head-pole) and E-effects (biased toward feet-pole). Apart from an onset effect, this tilt-dependent pattern of systematic SVV errors repeated itself in subsequent rotation cycles with little sign of worsening performance. Static SVV responses were qualitatively similar and consistent with previous reports but showed smaller A-effects. By contrast, dynamic SBT errors were small and unimodal, indicating that errors in visual-verticality estimates were not caused by errors in body-tilt estimation. We discuss these results in terms of predictions from a canal-otolith interaction model extended with a leaky integrator and an egocentric bias mechanism. We conclude that the egocentric-bias mechanism becomes more manifest during constant velocity roll-rotation and that perceptual errors due to incorrect disambiguation of the otolith signal are small despite the decay of canal signals.

scholarly journals Head Roll-Tilt Subjective Visual Vertical Test in the Diagnosis of Persistent Postural-Perceptual Dizziness

2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Chihiro Yagi ◽  
Yuka Morita ◽  
Meiko Kitazawa ◽  
Yoriko Nonomura ◽  
Tatsuya Yamagishi ◽  
...  
Keyword(s):  
Subjective Visual Vertical ◽  
Visual Vertical ◽  
Head Roll ◽  
Vertical Test ◽  
Roll Tilt

scholarly journals Human perception of whole body roll-tilt orientation in a hypogravity analog: underestimation and adaptation

2018 ◽  
Vol 120 (6) ◽  
pp. 3110-3121 ◽  
Author(s):  
Raquel C. Galvan-Garza ◽  
Torin K. Clark ◽  
David Sherwood ◽  
Ana Diaz-Artiles ◽  
Marissa Rosenberg ◽  
...  
Keyword(s):  
Perceptual Learning ◽  
Visual Feedback ◽  
Human Perception ◽  
The Body ◽  
Whole Body ◽  
Altered Gravity ◽  
Centripetal Acceleration ◽  
Body Roll ◽  
Visual Vertical ◽  
Roll Tilt

Overestimation of roll tilt in hypergravity (“G-excess” illusion) has been demonstrated, but corresponding sustained hypogravic conditions are impossible to create in ground laboratories. In this article we describe the first systematic experimental evidence that in a hypogravity analog, humans underestimate roll tilt. We studied perception of self-roll tilt in nine subjects, who were supine while spun on a centrifuge to create a hypogravity analog. By varying the centrifuge rotation rate, we modulated the centripetal acceleration (GC) at the subject’s head location (0.5 or 1 GC) along the body axis. We measured orientation perception using a subjective visual vertical task in which subjects aligned an illuminated bar with their perceived centripetal acceleration direction during tilts (±11.5–28.5°). As hypothesized, based on the reduced utricular otolith shearing, subjects initially underestimated roll tilts in the 0.5 GC condition compared with the 1 GC condition (mean perceptual gain change = −0.27, P = 0.01). When visual feedback was given after each trial in 0.5 GC, subjects’ perceptual gain increased in approximately exponential fashion over time (time constant = 16 tilts or 13 min), and after 45 min, the perceptual gain was not significantly different from the 1 GC baseline (mean gain difference between 1 GC initial and 0.5 GC final = 0.16, P = 0.3). Thus humans modified their interpretation of sensory cues to more correctly report orientation during this hypogravity analog. Quantifying the acute orientation perceptual learning in such an altered gravity environment may have implications for human space exploration on the moon or Mars. NEW & NOTEWORTHY Humans systematically overestimate roll tilt in hypergravity. However, human perception of orientation in hypogravity has not been quantified across a range of tilt angles. Using a centrifuge to create a hypogravity centripetal acceleration environment, we found initial underestimation of roll tilt. Providing static visual feedback, perceptual learning reduced underestimation during the hypogravity analog. These altered gravity orientation perceptual errors and adaptation may have implications for astronauts.

Tonic neck reflex of the decerebrate cat: response of spinal interneurons to natural stimulation of neck and vestibular receptors

1984 ◽  
Vol 51 (3) ◽  
pp. 567-577 ◽  
Author(s):  
V. J. Wilson ◽  
K. Ezure ◽  
S. J. Timerick
Keyword(s):  
Dynamic Behavior ◽  
Vestibular Stimulation ◽  
Whole Body ◽  
Type I ◽  
Type Ii ◽  
Vestibular Input ◽  
Ipsilateral Side ◽  
Neck Rotation ◽  
Roll Tilt ◽  
Tonic Neck Reflex

In order to investigate the neural basis of the tonic neck reflex, we studied the response of neurons in the cervical spinal cord of decerebrate, paralyzed cats to neck rotation about the longitudinal axis (roll), to vestibular stimulation produced by roll tilt, and to a combination of these stimuli. Most neurons were outside the motoneuron nuclei and were arbitrarily classified as interneurons. Three types of preparation were used--one with intact labyrinths, one acutely labyrinthectomized, and one with acute spinal transection. The activity of 115 neurons recorded extracellularly was modulated by sinusoidal neck rotation in the range 0.02-4 Hz; their behavior was sufficiently linear for sinusoidal analysis. The phase and gain of the responses of neurons in all three preparations were similar except that the absolute gain in cats with intact labyrinths was higher than that of the others. The location of neurons in segments C4-C8 was mainly in laminae 7-8. Some neurons were excited by rotation of the chin to the ipsilateral side (type I) and others by contralateral chin rotation (type II). The dynamic behavior of type I and type II neurons was the same; phase was flat over most of the frequency range and close to the phase of peak neck rotation, while gain enhancement occurred at higher frequencies. This behavior was similar to that of the neckforelimb reflex evoked in unparalyzed intact-labyrinth and labyrinthectomized cats. In cats with intact labyrinths, vestibular input to neurons whose activity was modulated by the neck stimulus was studied using whole-body roll tilt. Many neurons received otolith input; some received canal input. Neck and vestibular inputs to spinal neurons always had opposite polarities (complementary inputs). Thus, type I neurons were always excited by tilt to the ipsilateral side (ipsilateral ear down) while type II neurons were excited by tilt to the contralateral side. Combined neck and vestibular stimulation indicated that the dynamic behavior of neurons was determined by a linear summation of the responses to these stimuli. Interaction of neck and vestibular input at the neuron level was similar to that observed previously at the reflex level in forelimb extensor muscles.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Visual effects on the subjective visual vertical and subjective postural head vertical during static roll-tilt

2017 ◽  
Vol 2 (3) ◽  
pp. 125-130 ◽  
Author(s):  
Atsushi Tamura ◽  
Yoshiro Wada ◽  
Akihiro Kurita ◽  
Takeshi Matsunobu ◽  
Takuo Inui ◽  
...  
Keyword(s):  
Subjective Visual Vertical ◽  
Visual Effects ◽  
Visual Vertical ◽  
Roll Tilt

scholarly journals A Pathway in the Brainstem for Roll-Tilt of the Subjective Visual Vertical: Evidence from a Lesion-Behavior Mapping Study

2012 ◽  
Vol 32 (43) ◽  
pp. 14854-14858 ◽  
Author(s):  
B. Baier ◽  
F. Thomke ◽  
J. Wilting ◽  
C. Heinze ◽  
C. Geber ◽  
...  
Keyword(s):  
Subjective Visual Vertical ◽  
Mapping Study ◽  
Visual Vertical ◽  
Roll Tilt

scholarly journals Dynamic arm movements attenuate perceptual distortion of visual vertical induced during prolonged whole-body tilt

2020 ◽  
Author(s):  
Keisuke Tani ◽  
Shinji Yamamoto ◽  
Yasushi Kodaka ◽  
Keisuke Kushiro
Keyword(s):  
Central Nervous System ◽  
Arm Movements ◽  
Upright Position ◽  
Body Tilt ◽  
Whole Body ◽  
Subjective Visual Vertical ◽  
Body Movements ◽  
Perceptual Distortion ◽  
Visual Vertical ◽  
The Central Nervous System

AbstractAdditional gravitational cues generated by active body movements may play a role in the perception of gravitational space, but no experimental evidence has been shown on this. To investigate this possibility, we evaluated how arm movements made against gravity influenced the perceptual distortion of visual and postural vertical induced by prolonged whole-body tilt. In Experiment 1, participants were asked to perform static or dynamic arm movements during prolonged whole-body tilt and we assessed their effects on subjective visual vertical (SVV) at the tilt position (during-tilt session) and after tilting back to the upright position (post-tilt session). In Experiment 2, we evaluated how static or dynamic arm movements during prolonged tilt subsequently affected the subjective postural vertical (SPV). In Experiment 1, we observed that prolonged tilt induced the SVV shifts toward the side of body tilts in both sessions. The prolonged tilt-induced SVV shifts effectively decreased when performing dynamic arm movements in the during-tilt session, but not in the post-tilt session. In Experiment 2, the SPV shifted toward the side of prolonged body tilt, which was not significantly influenced by the performance of static or dynamic arm movements. Results of the during-tilt session suggest that the central nervous system utilizes additional cues generated by dynamic body movements for the perception of the visual vertical.

Dynamic Effects on the Subjective Visual Vertical After Roll Rotation

2008 ◽  
Vol 100 (2) ◽  
pp. 657-669 ◽  
Author(s):  
Erika N. Lorincz ◽  
Bernhard J. M. Hess
Keyword(s):  
Semicircular Canal ◽  
Constant Velocity ◽  
Human Subjects ◽  
Subjective Visual Vertical ◽  
Dynamic Effects ◽  
Complete Darkness ◽  
Constant Acceleration ◽  
Visual Vertical ◽  
Normal Human ◽  
Roll Tilt

We investigated in normal human subjects how semicircular canal and otolith signals interact in the estimation of the subjective visual vertical after constant velocity or constant acceleration roll tilt. In the constant velocity paradigm, subjects were rotated in darkness at ±60°/s for five complete cycles before being stopped in one of seven orientations ranging from 0 to ±90° (right/left ear down). In the constant acceleration paradigm, subjects were rotated with an acceleration of +30 or −30°/s2 to the same seven end positions between −90 and +90°, by way of passing once through the upside-down position. The subjective visual vertical was assessed by measuring the setting of a luminous line that appeared at different test delays after stop rotation in otherwise complete darkness. The data suggest that gravitational jerk signals generated by otolith–semicircular canal interactions and/or carried by phasic otolith signals are responsible for the observed transient bias in the estimation of the subjective visual vertical. This transient bias depended on both rotation and tilt direction after constant velocity rotations, but was almost abolished following constant acceleration rotations.

scholarly journals Roll Tilt Psychophysics in Rhesus Monkeys During Vestibular and Visual Stimulation

2008 ◽  
Vol 100 (1) ◽  
pp. 140-153 ◽  
Author(s):  
Richard F. Lewis ◽  
Csilla Haburcakova ◽  
Daniel M. Merfeld
Keyword(s):  
Rhesus Monkeys ◽  
Visual Stimulation ◽  
Inertial Force ◽  
Semicircular Canals ◽  
Head Orientation ◽  
Optokinetic Stimulation ◽  
Behavioral Measures ◽  
Visual Vertical ◽  
Fixed Radius ◽  
Roll Tilt

How does the brain calculate the spatial orientation of the head relative to gravity? Psychophysical measurements are critical to investigate this question, but such measurements have been limited to humans. In non-human primates, behavioral measures have focused on vestibular-mediated eye movements, which do not reflect percepts of head orientation. We have therefore developed a method to measure tilt perception in monkeys, derived from the subjective visual vertical (SVV) task. Two rhesus monkeys were trained to align a light bar parallel to gravity and performed this task during roll tilts, centrifugation, and roll optokinetic stimulation. The monkeys accurately aligned the light bar with gravity during static roll tilts but also demonstrated small orientation-dependent misperceptions of the tilt angle analogous to those measured in humans. When the gravito-inertial force (GIF) rotated dynamically in the roll plane, SVV responses remained closely aligned with the GIF during roll tilt of the head (coplanar canal rotational cues present), lagged slightly behind the GIF during variable-radius centrifugation (no canal cues present), and shifted gradually during fixed-radius centrifugation (orthogonal yaw canal cues present). SVV responses also deviated away from the earth-vertical during roll optokinetic stimulation. These results demonstrate that rotational cues derived from the semicircular canals and visual system have prominent effects on psychophysical measurements of roll tilt in rhesus monkeys and therefore suggest that a central synthesis of graviceptive and rotational cues contributes to percepts of head orientation relative to gravity in non-human primates.

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