scholarly journals Contribution of Somesthetic Information to the Perception of Body Orientation in the Pitch Dimension

2003 ◽  
Vol 56 (5) ◽  
pp. 909-923 ◽  
Author(s):  
Lionel Bringoux ◽  
Vincent Nougier ◽  
Ludovic Marin ◽  
Pierre-Alain Barraud ◽  
Christian Raphel
Keyword(s):  
The Body ◽  
Body Orientation ◽  
Body Tilt ◽  
Vertical Position ◽  
Starting Position ◽  
Pitch Dimension ◽  
Cast Condition ◽  
Static Body ◽  
Body Cast

This study investigated the contribution of otolithic and somesthetic inputs in the perception of body orientation when pitching at very slow velocities. In Experiment 1, the subjects’ task was to indicate their subjective postural vertical, in two different conditions of body restriction, starting from different angles of body tilt. In the “strapped” condition, subjects were attached onto a platform by means of large straps. In the “body cast” condition, subjects were completely immobilized in a depressurized system, which attenuates gravity-based somesthetic cues. Results showed that the condition of body restriction and the initial tilt largely influenced the subjective postural vertical. In Experiment 2, subjects were displaced from a vertical position and had to detect the direction of body tilts. Results showed that the threshold for the perception of body tilt was higher when subjects were immobilized in the body cast and when they were tilted backward. Experiment 3 replicated the same protocol from a supine starting position. Compared to results of Experiment 2, the threshold for the perception of body tilt decreased significantly. Overall, these data suggested that gravity-based somesthetic cues are more informative than otolithic cues for the perception of a quasi-static body orientation.

Effects of gymnastics expertise on the perception of body orientation in the pitch dimension

2000 ◽  
Vol 10 (6) ◽  
pp. 251-258 ◽  
Author(s):  
Lionel Bringoux ◽  
Ludovic Marin ◽  
Vincent Nougier ◽  
Pierre-Alain Barraud ◽  
Christian Raphel
Keyword(s):  
Postural Control ◽  
Motor Skills ◽  
The Body ◽  
Body Orientation ◽  
Body Tilt ◽  
Sensory Cues ◽  
Specific Training ◽  
Pitch Dimension ◽  
Pitch Tilt ◽  
Body Cast

The purpose of this study was to investigate how experts in motor skills requiring a fine postural control perceive their body orientation with few gravity based sensory cues. In Experiment 1, expert gymnasts and controls had to detect their body tilt when pitching at a velocity of 0.05 deg . s − 1 , in two conditions of body restriction (strapped and body cast altering the somatosensory cues). Contrary to the experts, the controls exhibited a larger body tilt when totally restrained in the body cast. In Experiment 2, subjects had to estimate their Subjective Postural Vertical (SPV) starting from different angles of pitch tilt. The controls exhibited significant errors of SPV judgement whereas the experts were very precise. These results suggest that 1) somatosensory cues are more informative than otolithic cues for the perception of body orientation, and 2) the efficiency of otolithic and/or interoceptive inputs can be improved through a specific training to compensate for the lack of somatosensory cues.

scholarly journals Neck Muscle Vibration and Spatial Orientation During Stepping in Place in Humans

2002 ◽  
Vol 88 (5) ◽  
pp. 2232-2241 ◽  
Author(s):  
Marco Bove ◽  
Gregoire Courtine ◽  
Marco Schieppati
Keyword(s):  
The Body ◽  
Body Orientation ◽  
Body Tilt ◽  
Whole Body ◽  
Neck Muscle ◽  
Body Rotation ◽  
Erect Posture ◽  
Proprioceptive Input ◽  
Neck Muscle Vibration ◽  
Stepping In Place

Unilateral long-lasting vibration was applied to the sternomastoid muscle to assess the influence of asymmetric neck proprioceptive input on body orientation during stepping-in-place. Blindfolded subjects performed 3 sequences of 3 trials, each lasting 60 s: control, vibration applied during stepping (VDS), and vibration applied before stepping (VBS). VDS caused clear-cut whole body rotation toward the side opposite to vibration. The body rotated around a vertical axis placed at about arm's length from the body. The rotation did not begin immediately on switching on the vibrator. The delay varied from subject to subject from a few seconds to about 10 s. Once initiated, the angular velocity of rotation was remarkably constant (about 1°/s). In VBS, at the beginning of stepping, subjects rotated for a while as if their neck were still vibrated. At a variable delay, the direction of rotation reversed, and the effects were opposite to those observed during VDS. Under no condition did head rotation, head roll, or lateral body tilt accompany rotation. The results confirm and extend the notion that the neck proprioceptive input plays a major role in body orientation during locomotion. The body rotation does not seem to depend on the same mechanisms that modify the erect posture; rather, the asymmetric neck input would seem to modify the egocentric body-centered coordinate system.

Lateropulsion After Hemispheric Stroke: A Form of Spatial Neglect Involving Graviception

Neurology ◽  
2021 ◽  
pp. 10.1212/WNL.0000000000011826
Author(s):  
Shenhao Dai ◽  
Céline Piscicelli ◽  
Emmanuelle Clarac ◽  
Monica Baciu ◽  
Marc Hommel ◽  
...  
Keyword(s):  
The Body ◽  
Spatial Neglect ◽  
Body Orientation ◽  
Body Tilt ◽  
Vertical Orientation ◽  
Lateral Body ◽  
Pusher Syndrome ◽  
Visual Vertical ◽  
Straight Ahead ◽  
Cardinal Sign

ObjectiveTo test the hypothesis that lateropulsion is an entity expressing an impaired body orientation with respect to gravity, in relation to a biased graviception and spatial neglect.MethodsData from the DOBRAS cohort (ClinicalTrials.gov:NCT03203109), were collected 30 days after a first hemisphere stroke. Lateral body tilt, pushing and resistance were assessed with the Scale for Contraversive Pushing.ResultsAmong 220 individuals, 72% were Upright and 28% showed lateropulsion (Tilters=14% less severe than Pushers=14%). The three signs had very high factor loadings (>0.90) on a same dimension, demonstrating that lateropulsion was effectively an entity comprising body tilt (cardinal sign), pushing and resistance. The factorial analyses also showed that lateropulsion was inseparable from the visual vertical (VV), a criterion referring to vertical orientation (graviception). Contralesional VV biases were frequent (44%), with a magnitude related to lateropulsion severity: Upright -0.6°(-2.9;2.4), Tilters -2.9°(-7;0.8), Pushers -12.3°(-15.4;-8.5). Ipsilesional VV biases were less frequent and milder (p<0.001). They did not deal with graviception, 84% being found in upright individuals. Multivariate, factorial, contingency, and prediction analyses congruently showed strong similarities between lateropulsion and spatial neglect, the latter encompassing the former.ConclusionsLateropulsion (pusher syndrome) is a trinity constituted by body tilt, pushing and resistance. It is a way to adjust the body orientation in the roll plane to a wrong reference of verticality. Referring to straight above, lateropulsion might correspond to a form of spatial neglect (referring to straight ahead), which would advocate for 3-D maps in the human brain involving the internal model of verticality.

Perception of the Auditory Midline and Visual Vertical in Brain-Damaged and Non-Brain-Damaged Humans

1973 ◽  
Vol 37 (2) ◽  
pp. 627-634
Author(s):  
Robert B. Welch ◽  
Gerald Goldstein ◽  
Carolyn H. Shelly
Keyword(s):  
Psychiatric Patients ◽  
Underlying Mechanism ◽  
The Body ◽  
Body Orientation ◽  
Position Effects ◽  
Starting Position ◽  
Visual Vertical

Three groups of Ss—brain-damaged, hospitalized psychiatric patients, and normals—were administered the auditory-midline and visual-vertical tests with body orientation of right-tilt, left-tilt, and upright. Performance on the two tasks was not correlated, a finding that argues against the hypothesis of a common underlying mechanism. Only the normals showed the visual “E-effect” (overconstancy in setting the line to true vertical) when the body was placed on a tilt. “Starting position effects” on both tasks were most pronounced for the braindamaged Ss and least for normals.

Unilateral Auditory Stimulation and the Visual Perception of Verticality: One More Time

1980 ◽  
Vol 50 (1) ◽  
pp. 171-182
Author(s):  
H. D. Day ◽  
L. F. Shelly
Keyword(s):  
Field Theory ◽  
Visual Perception ◽  
Auditory Stimulation ◽  
Vertical Position ◽  
Starting Position ◽  
Perception Of Verticality

The effects of varying conditions of unilateral auditory stimulation on the visual perception of verticality were examined in two experiments using 18 and 42 subjects, respectively. Significant effects of auditory stimulation and hand used to make the verticality adjustments were not found. With only one exception in Exp. 2, the starting position of the rod also had no influence on the ability of the subjects to adjust a rod to its vertical position. The literature pertaining to sensory-tonic field theory of perception was critically reviewed.

scholarly journals Development and evaluation of low-cost walker with trunk support for senior citizen

2017 ◽  
Vol 51 (0) ◽  
Author(s):  
Paloma Hohmann Poier ◽  
Francisco Godke ◽  
José Aguiomar Foggiatto ◽  
Leandra Ulbricht
Keyword(s):  
Senior Citizens ◽  
Low Cost ◽  
Senior Citizen ◽  
Descriptive Study ◽  
The Body ◽  
Two Stage ◽  
Monitoring Time ◽  
Static Body ◽  
Study Development

Abstract OBJECTIVE Develop and evaluate a low-cost walker with trunk support for senior citizens. METHOD Two-stage descriptive study: development of a walker with trunk support and evaluation with fourth age senior citizens. RESULTS Twenty-three fourth age senior citizens were selected. The evaluated criteria were the immediate influence of the walker on the static stabilometry with baropodometer and the evaluation of gait with accelerometers monitoring time and amplitude of the hip movement. There was a significant decrease in the body oscillation of senior citizens with the use of the developed walker, and there were changes in the joint amplitudes of the hip, but they were not significant. CONCLUSION Using low-cost materials, it was possible to develop and equipment that met resistance and effectiveness requirements. The walker interfered in the balance of the senior citizens, reducing significantly the static body oscillation.

Light Organ and Eyestalk Compensation to Body Tilt in the Luminescent Midwater Shrimp, Sergestes Similis

1982 ◽  
Vol 98 (1) ◽  
pp. 83-104
Author(s):  
MICHAEL I. LATZ ◽  
JAMES F. CASE
Keyword(s):  
Angular Distribution ◽  
Light Source ◽  
The Body ◽  
Body Tilt ◽  
Light Organ ◽  
Total Compensation ◽  
Angular Movement ◽  
Counter Rotation ◽  
Light Organs ◽  
Before And After

The posterior light organ and eyestalk of the midwater shrimp, Sergestes similis Hansen, are capable of 140° of angular movement within the body during pitch body tilt, maintaining the organs at near horizontal orientations. Counter-rotations compensate for 74–80% of body inclination. These responses are statocyst mediated. Unilateral statolith ablation reduces compensation by 50%. There is no evidence for either homolateral or contralateral control by the single functioning statocyst. Bilateral lith ablation abolishes counter-rotation. Light organ and eyestalk orientations are unaffected by the direction of imposed body tilt. Bioluminescence is emitted downward from horizontal animals with an angular distribution similar to the distribution of oceanic light. The amount of downward directed luminescence in tilted animals decreases at large angles of body inclination due to less than total compensation by the light organs. Eye turning towards a light source is induced by upward-directed illumination. The resulting change in eyestalk orientations never amounts to more than 25°. The turning is abolished by bilateral statolith ablation. Downward directed illumination, comparable in intensity to oceanic light, generally does not generate significant eye turning. Light organ orientations remain unaffected by directional illumination, both before and after bilateral statolith ablation. The compensatory counter-rotations by the posterior light organ and eyestalk suggest that counter-illumination by S. similis remains effective in inclined animals.

Modulation of Spatial Orientation Processing by Mental Imagery Instructions: A MEG Study of Representational Momentum

2000 ◽  
Vol 12 (4) ◽  
pp. 569-582 ◽  
Author(s):  
Michel-Ange Amorim ◽  
Wilfried Lang ◽  
Gerald Lindinger ◽  
Dagmar Mayer ◽  
Lüder Deecke ◽  
...  
Keyword(s):  
Mental Imagery ◽  
Spatial Orientation ◽  
Visual Motion ◽  
Brain Activity ◽  
Representational Momentum ◽  
The Body ◽  
Body Motion ◽  
Body Tilt ◽  
Rotational Equilibrium ◽  
The Right

Under appropriate conditions, an observer's memory for the final position of an abruptly halted moving object is distorted in the direction of the represented motion. This phenomenon is called “representational momentum” (RM). We examined the effect of mental imagery instructions on the modulation of spatial orientation processing by testing for RM under conditions of picture versus body rotation perception and imagination. Behavioral data were gathered via classical reaction time and error measurements, whereas brain activity was recorded with the help of magnetoence-phalography (MEG). Due to the so-called inverse problem and to signal complexity, results were described at the signal level rather than with the source location modeling. Brain magnetic field strength and spatial distribution, as well as latency of P200m evoked fields were used as neurocognitive markers. A task was devised where a subject examined a rotating sea horizon as seen from a virtual boat in order to extrapolate either the picture motion or the body motion relative to the picture while the latter disappeared temporarily until a test-view was displayed as a final orientation candidate. Results suggest that perceptual interpretation and extrapolation of visual motion in the roll plane capitalize on the fronto-parietal cortical networks involving working memory processes. Extrapolation of the rotational dynamics of sea horizon revealed a RM effect simulating the role of gravity in rotational equilibrium. Modulation of the P200m component reflected spatial orientation processing and a non-voluntary detection of an incongruity between displayed and expected final orientations given the implied motion. Neuromagnetic properties of anticipatory (Contingent Magnetic Variation) and evoked (P200m) brain magnetic fields suggest, respectively, differential allocation of attentional resources by mental imagery instructions (picture vs. body tilt), and a communality of neural structures (in the right centro-parietal region) for the control of both RM and mental rotation processes. Finally, the RM of the body motion is less prone to forward shifts than that of picture motion evidencing an internalization of the implied mass of the virtual body of the observer.

Haptic object recognition is influenced by the orientation of the body relative to gravity

2012 ◽  
Vol 25 (0) ◽  
pp. 122
Author(s):  
Michael Barnett-Cowan ◽  
Jody C. Culham ◽  
Jacqueline C. Snow
Keyword(s):  
Object Recognition ◽  
Character Recognition ◽  
Reference Frames ◽  
Sensory Information ◽  
The Body ◽  
Body Orientation ◽  
Visual Object ◽  
Visual Object Recognition ◽  
Leftward Bias ◽  
Haptic Object

The orientation at which objects are most easily recognized — the perceptual upright (PU) — is influenced by body orientation with respect to gravity. To date, the influence of these cues on object recognition has only been measured within the visual system. Here we investigate whether objects explored through touch alone are similarly influenced by body and gravitational information. Using the Oriented CHAracter Recognition Test (OCHART) adapted for haptics, blindfolded right-handed observers indicated whether the symbol ‘p’ presented in various orientations was the letter ‘p’ or ‘d’ following active touch. The average of ‘p-to-d’ and ‘d-to-p’ transitions was taken as the haptic PU. Sensory information was manipulated by positioning observers in different orientations relative to gravity with the head, body, and hand aligned. Results show that haptic object recognition is equally influenced by body and gravitational references frames, but with a constant leftward bias. This leftward bias in the haptic PU resembles leftward biases reported for visual object recognition. The influence of body orientation and gravity on the haptic PU was well predicted by an equally weighted vectorial sum of the directions indicated by these cues. Our results demonstrate that information from different reference frames influence the perceptual upright in haptic object recognition. Taken together with similar investigations in vision, our findings suggest that reliance on body and gravitational frames of reference helps maintain optimal object recognition. Equally relying on body and gravitational information may facilitate haptic exploration with an upright posture, while compensating for poor vestibular sensitivity when tilted.

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