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 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 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

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.

Topology of brainstem lesions associated with subjective visual vertical tilt

Neurology ◽  
2014 ◽  
Vol 82 (22) ◽  
pp. 1968-1975 ◽  
Author(s):  
T.-H. Yang ◽  
S.-Y. Oh ◽  
K. Kwak ◽  
J.-M. Lee ◽  
B.-S. Shin ◽  
...  
Keyword(s):  
Subjective Visual Vertical ◽  
Brainstem Lesions ◽  
Visual Vertical

scholarly journals The use of a neck brace does not influence visual vertical perception

2011 ◽  
Vol 69 (3) ◽  
pp. 509-512 ◽  
Author(s):  
Martha Funabashi ◽  
Natya N.L. Silva ◽  
Luciana M. Watanabe ◽  
Taiza E.G Santos-Pontelli ◽  
José Fernando Colafêmina ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Healthy Subjects ◽  
Afferent Input ◽  
Subjective Visual Vertical ◽  
Sensory Receptors ◽  
Ocular Torsion ◽  
Vertical Orientation ◽  
Mean Values ◽  
Visual Vertical ◽  
The Mean

Subjective visual vertical (SVV) evaluates the individual's capacity to determine the vertical orientation. Using a neck brace (NB) allow volunteers' heads fixation to reduce cephalic tilt during the exam, preventing compensatory ocular torsion and erroneous influence on SVV result. OBJECTIVE: To analyze the influence of somatosensory inputs caused by a NB on the SVV. METHOD: Thirty healthy volunteers performed static and dynamic SVV: six measures with and six without the NB. RESULTS: The mean values for static SVV were -0.075º±1.15º without NB and -0.372º±1.21º with NB. For dynamic SVV in clockwise direction were 1.73º±2.31º without NB and 1.53º±1.80º with NB. For dynamic SVV in counterclockwise direction was -1.50º±2.44º without NB and -1.11º±2.46º with NB. Differences between measurements with and without the NB were not statistically significant. CONCLUSION: Although the neck has many sensory receptors, the use of a NB does not provide sufficient afferent input to change healthy subjects' perception of visual verticality.

Sign in / Sign up

Export Citation Format

Share Document