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Laurens Jean - - 2007
Complex self-motion stimulations in the dark can be powerfully disorienting and can create illusory motion percepts. In the absence of visual cues, the brain has to use angular and linear acceleration information provided by the vestibular canals and the otoliths, respectively. However, these sensors are inaccurate and ambiguous. We propose ...
Wickens Christopher D - - 2006
INTRODUCTION: Aviation spatial disorientation mishaps remain a concern, especially due to their fatality rate. Some of the most insidious disorientations are due to vestibular stimuli in the absence of visual cues. A category of such disorientations are known as somatogyral illusions. METHODS: To determine the effects of spin rate and ...
Tong Jianliang - - 2006
The extent of perceived motion smear was compared for targets that underwent similar velocities of retinal image motion during the vestibulo-ocular reflex (VOR) in the dark, the visually enhanced VOR (VVOR), VOR suppression, and fixation. Compared to the extent of perceived motion smear during fixation, observers reported significantly less smear ...
Macuga Kristen L KL Department of Psychology, University of California, Santa Barbara, CA 93106-9660, USA. - - 2007
Can driver steering behaviors, such as a lane change, be executed without visual feedback? In a recent study with a fixed-base driving simulator, drivers failed to execute the return phase of a lane change when steering without vision, resulting in systematic final heading errors biased in the direction of the ...
Pockett Susan - - 2007
The rotating spot method of timing subjective events involves the subject's watching a rotating spot on a computer and reporting the position of the spot at the instant when the subjective event of interest occurs. We conducted an experiment to investigate factors that may impact on the results produced by ...
Ohman Filip - - 2006
We demonstrate the use of coherent population oscillations (CPO) to realize a monolithically integrated semiconductor device which allows voltage controlled tuning of the group velocity corresponding to a phase shift of up to 55 degrees at a frequency of 10 GHz. By combining sections of slow and fast light, corresponding ...
Yao Eric - - 2006
We demonstrate the Fourier relationship between angular position and angular momentum for a light mode. In particular we measure the distribution of orbital angular momentum states of light that has passed through an aperture and verify that the orbital angular momentum distribution is given by the complex Fourier-transform of the ...
Holly Jan E - - 2006
Angular and linear accelerations of the head occur throughout everyday life, whether from external forces such as in a vehicle or from volitional head movements. The relative timing of the angular and linear components of motion differs depending on the movement. The inner ear detects the angular and linear components ...
Towal R Blythe - - 2006
Rats use rhythmic movements of their vibrissae (whiskers) to tactually explore their environment. This "whisking" behavior has generally been reported to be strictly synchronous and symmetric about the snout, and it is thought to be controlled by a brainstem central pattern generator. Because the vibrissae can move independently of the ...
Todorović Dejan - - 2006
Perception of gaze direction depends not only on the position of the irises within the looker's eyes but also on the orientation of the looker's head. A simple analysis of the geometry of gaze direction predicts this dependence. This analysis is applied to explain the Wollaston effect, the Mona Lisa ...
Fitzpatrick Richard C RC Prince of Wales Medical Research Institute and University of New South Wales, Sydney 2031, Australia. - - 2006
Alignment of the body to the gravitational vertical is considered to be the key to human bipedalism. However, changes to the semicircular canals during human evolution suggest that the sense of head rotation that they provide is important for modern human bipedal locomotion. When walking, the canals signal a mix ...
Jürgens Reinhart R Sektion Neurophysiologie, Universität Ulm, Albert-Einstein-Allee 47, 89081 Ulm, - - 2006
The perception of angular displacement during self turning is generally based on a combination of redundant signals from different sources. For example, during active turning in a visually structured environment devoid of landmarks, podokinesthetic, vestibular, and optokinetic velocity signals are fused and integrated over time to yield a unitary percept ...
Macuga Kristen L - - 2006
How do we determine where we are heading during visually controlled locomotion? Psychophysical research has shown that humans are quite good at judging their travel direction, or heading, from retinal optic flow. Here we show that retinal optic flow is sufficient, but not necessary, for determining heading. By using a ...
Sadeghi Soroush G SG Department of Physiology, Aerospace Medical Research Unit, McGill University, 3655 Drummond St., H3G 1Y6 Montreal, QC - - 2006
Loss of vestibular information from one labyrinth results in a marked asymmetry in the horizontal vestibuloocular reflex (VOR). The results of prior studies suggest that long-term deficits in VOR are more severe in response to rapid impulses than to sinusoidal head movements. The goal of the present study was to ...
Ramachandran Ramnarayan - - 2006
Parallel pathways mediate the rotatory vestibuloocular reflex (VOR). If the VOR undergoes adaptive modification with spectacles that change the magnification of the visual scene, signals in one neural pathway are modified, whereas those in another are not. By recording the responses of vestibular afferents and abducens neurons for vestibular oscillations ...
Israël I - - 2006
The vestibular system detects the velocity of the head even in complete darkness, and thus contributes to spatial orientation. However, during vestibular estimation of linear passive self-motion distance in darkness, healthy human subjects mainly rely on time, and they replicate also stimulus duration when required to reproduce previous self-rotation. We ...
Aw S T - - 2006
BACKGROUND: An enlarged, low-threshold click-evoked vestibulo-ocular reflex (VOR) can be averaged from the vertical electro-oculogram in a superior canal dehiscence (SCD), a temporal bone defect between the superior semicircular canal and middle cranial fossa. OBJECTIVE: To determine the origin and quantitative stimulus-response properties of the click-evoked VOR. METHODS: Three-dimensional, binocular ...
Carriot Jérôme J Département des facteurs humains, Centre de Recherches du Service de Santé des Armées, BP 87-38702, La Tronche Cedex, Grenoble, - - 2006
Perception of tilt (somatogravic illusion) in response to sustained linear acceleration is generally attributed to the otolithic system which reflects either a translation of the head or a reorientation of the head with respect to gravity (tilt/translation ambiguity). The main aim of this study was to compare the tilt perception ...
Smith Suzanne D - - 2006
INTRODUCTION: There are potential effects of vibration on aircrew performance and safety when using helmet-mounted equipment. The objective of this study was to quantify the effects of head orientation and helmet center-of-gravity (CG) on head and helmet biodynamics and tracking performance during exposures to aircraft buffeting and quasi-random vibration. METHODS: ...
Park Sukyung S Jenks Vestibular Physiology Laboratory, Massachusetts Eye and Ear Infirmary, Havard Medical School, Boston, MA 02114, - - 2006
We investigated how the nervous system processes ambiguous cues from the otolith organs by measuring roll tilt perception elicited by two motion paradigms. In one paradigm (tilt), eight subjects were sinusoidally tilted in roll with the axis of rotation near ear level. Stimulus frequencies ranged from 0.005 to 0.7 Hz, ...
Knox Joanna J JJ Division of Physiotherapy, School of Health and Rehabilitation Sciences, The University of Queensland, 4072 Brisbane, Qld, - - 2006
Reproduction of a previously presented elbow position is affected by changes in head position. As movement of the head is associated with local biomechanical changes, the aim of the present study was to determine if illusory changes in head position could induce similar effects on the reproduction of elbow position. ...
van Riet R P - - 2006
Background. The treatment of radial head fractures that are not amenable to an open reduction and internal fixation, remains to be a difficult issue. A potential problem with prosthetic replacement of the radial head is the shape of current radial head prostheses. The purpose of this study was to determine ...
Sinawat S - - 2006
A 47 year-old Thai man presented with acute bilateral blindness after suffering head trauma in a motorcycle accident. No neurological deficit was found. The visual acuity was light perception with poor light projection on both eyes. Other ocular examinations were normal except ecchymosis on both lower eyelids and mild subconjunctival ...
Teo Ee Chon - - 2007
In this study, a detailed three-dimensional head-neck (C0-C7) finite element (FE) model developed previously based on the actual geometry of a human cadaver specimen was used. Five simulation analyses were performed to investigate the kinematic responses of the head-neck complex under rear-end, front, side, rear- and front-side impacts. Under rear-end ...
Wright W G WG Department of Neurology and Center for Sensorimotor Research, Klinikum Grosshadern, Ludwig-Maximilians University, 81377, Munich, Germany. - - 2006
To investigate how visual and vestibular cues are integrated for the perception of gravity during passive self-motion, we measured the ability to maintain a handheld object vertical relative to gravity without visual feedback during sinusoidal roll-tilt stimulation. Visual input, either concordant or discordant with actual dynamic roll-tilt, was delivered by ...
Marti Sarah S Neurology Department, Zurich University Hospital, Frauenklinikstrasse 26, 8091 Zurich, Switzerland. - - 2006
Anatomical and electrophysiological studies have demonstrated up-down asymmetries in vertical ocular motor pathways. We investigated whether these asymmetries extend to the capacity for short-term adaptation of the vertical vestibulo-ocular reflex (VVOR) in humans. Specifically, we asked whether smooth pursuit signals are sufficient to asymmetrically adapt the VVOR. Healthy human subjects ...
Hullar Timothy E TE Department of Otolaryngology-Head and Neck Surgery, Washington University School of Medicine, 660 South Euclid Avenue #8115, Saint Louis, MO 63110, USA. - - 2006
The orientations of the semicircular canals determines the response of the canals to head rotations and, in turn, the brain's ability to interpret those motions. The geometry of chinchillas' semicircular canals has never been reported. Volumetric representations of three chinchilla skulls were generated using a microCT scanner. The centroids of ...
Yoshikawa Akimasa A Dept. of Comput. Sci., Chubu Univ., Aichi, - - 2006
The vestibule ocular reflex (VOR), in which cerebellum is intimately involved to produce compensatory eye movements during head motion to stabilize retinal image. The VOR is under adaptive control whose gain (eye velocity/head velocity) can be modified by visual-vestibular mismatch stimuli. It exhibits frequency selectivity in which largest gain change ...
Ferraresi Aldo - - 2006
Sinusoidal vestibular stimulation induces in the intact rabbit in prone position a periodic alternating drift (PAD), evident in the earth horizontal plane when the animal is rotated about the vertical axis but weak in the vertical one when the animal is rotated about the longitudinal axis. It has been hypothesized ...
Li Li - - 2006
It has previously been reported that humans can determine their direction of 3D translation (heading) from the 2D velocity field of retinal motion experienced during self-motion through a rigid environment, as is done by current computational models of visual heading estimation from optic flow. However, these claims were supported by ...
Gdowski G T GT Dept. of Biomed. Eng., Rochester Univ., NY 14642, - - 2006
When the body is passively moved in space the mass of the head imposes force on the cervical spinal column. Reflexive activation of the neck musculature during whole body motion is hypothesized to function to counteract the inertial forces of the head. However, even when the body is stationary in ...
Dai Mingjia M Department of Neurology, Mount Sinai School of Medicine, 1 East 100th Street, Box 1135, New York, NY 10029-6574, USA. - - 2006
The purpose of this study was to determine the effect of baclofen, a GABA(B) agonist on the angular vestibulo-ocular reflex (aVOR). Model studies have shown that the aVOR comprises a "direct" pathway, which determines its high frequency gain g (1), and an indirect "velocity storage" pathway, which determines its low ...
Kaptein Ronald G - - 2006
Using vestibular sensors to maintain visual stability during changes in head tilt, crucial when panoramic cues are not available, presents a computational challenge. Reliance on the otoliths requires a neural strategy for resolving their tilt/translation ambiguity, such as canal-otolith interaction or frequency segregation. The canal signal is subject to bandwidth ...
Vingerhoets R A A - - 2006
Human spatial orientation relies on vision, somatosensory cues, and signals from the semicircular canals and the otoliths. The canals measure rotation, whereas the otoliths are linear accelerometers, sensitive to tilt and translation. To disambiguate the otolith signal, two main hypotheses have been proposed: frequency segregation and canal-otolith interaction. So far ...
Stevens Elizabeth S ES Department of Biology, Washington University, St. Louis, MO 63108, - - 2006
The purpose of this work was to determine whether walking on a rotating disc would cause changes in perception of active and passive turning. Ten healthy control subjects wore a blindfold and earplugs while completing trials of active and passive turning. For active conditions, subjects were told the direction and ...
Melvill Jones G G Department of Clinical Neurosciences, University of Calgary, 3330 Hospital Drive, NW Calgary, AB, Canada, T2N 4N1. - - 2005
After prolonged stepping in place relative to space over the center of a rotating turntable, blindfolded subjects cannot step on the stationary platform without unknowingly turning themselves relative to space, a phenomenon termed podokinetic after rotation (PKAR). We asked what role the resulting vestibular stimulation might play in the expression ...
Deshpande Nandini N Gait and Posture Laboratory, Department of Kinesiology, University of Waterloo, Waterloo, ON, - - 2005
Both vestibular and neck proprioceptive inputs contribute towards maintaining a walking trajectory. We investigated how aging alters neck proprioceptive and vestibular interaction for preserving equilibrium and spatial orientation during locomotion. Young and healthy elderly were exposed to two sensory manipulations as they walked, eyes closed, to a target located straight ...
Temperley David - - 2005
Hudson (1990) proposes that each conjunct in a coordinate phrase forms dependency relations with heads or dependents outside the coordinate phrase (the "multi-head" view). This proposal is tested through corpus analysis of Wall Street Journal text. For right-branching constituents (such as direct-object NPs), a short-long preference for conjunct ordering is ...
Baker James F JF Department of Physiology and Institute for Neuroscience Physiology/Medical, Ward 5-071, M211, Northwestern University Medical School, 303 East Chicago Avenue, Chicago, IL 60611-3008, USA. - - 2005
The vestibulo-collic reflex (VCR) stabilizes the head in space by excitation of neck muscles that oppose head rotation. Recently, the mouse vestibulo-ocular reflex (VOR) has been characterized so that genetic manipulations of the vestibular system can be examined. We have characterized the dynamics and directionality of the VCR in mice ...
Sprenger A - - 2006
Recovery from vestibular neuritis (VN) is often incomplete which leads to persistent vestibular imbalance during rapid head movements. Patients with unilateral vestibular lesions have a larger gain of the horizontal vestibulo-ocular reflex during active compared to passive head movements. To test whether this gain increase is related to predictive mechanisms ...
Okamoto Takashi - - 2005
The light amplification properties of fractal and asymmetric multilayer resonator structures which contain a light amplifying medium in the middle layer are studied theoretically. The amplitude gain of transmitted light is analyzed by use of two-dimensional plots which we denote gain maps. The gain map, which is plotted against two ...
Maki Katuhiro - - 2005
This study examines individual differences in the directional transfer functions (DTFs), the directional components of head-related transfer functions of gerbils, and seeks a method for reducing these differences. The difference between the DTFs of a given animal pair was quantified by the intersubject spectral difference (ISSD), which is the variance ...
Wilkie Richard M - - 2005
During locomotion, retinal flow, gaze angle, and vestibular information can contribute to one's perception of self-motion. Their respective roles were investigated during active steering: Retinal flow and gaze angle were biased by altering the visual information during computer-simulated locomotion, and vestibular information was controlled through use of a motorized chair ...
Tribukait Arne - - 2005
BACKGROUND: Spatial disorientation is an important problem in aviation. The mechanisms behind the sensation of roll tilt during coordinated turns are not well known. The present study aimed at elucidating what kind of semicircular canal information might cause tilts of the subjective horizontal during gondola centrifugation. METHODS: The subjective visual ...
Figliozzi Francesca - - 2005
Peripheral vestibular organs feed the central nervous system with inputs favoring the correct perception of space during head and body motion. Applying temporal order judgments (TOJs) to pairs of simultaneous or asynchronous stimuli presented in the left and right egocentric space, we evaluated the influence of leftward and rightward vestibular ...
Shaikh Aasef G - - 2005
Our inner ear is equipped with a set of linear accelerometers, the otolith organs, that sense the inertial accelerations experienced during self-motion. However, as Einstein pointed out nearly a century ago, this signal would by itself be insufficient to detect our real movement, because gravity, another form of linear acceleration, ...
Yoo Seung-Schik - - 2005
OBJECTIVES: Functional MRI (fMRI) has become an important imaging modality for analyzing the neural mechanisms underlying schizophrenia. Earlier studies indicate that patients with schizophrenia tend to generate involuntary and unnecessary head motion during visual tasks. Since head motion can deteriorate the quality of fMRI data, an investigation was needed to ...
Green Andrea M - - 2005
The ability to navigate in the world and execute appropriate behavioral and motor responses depends critically on our capacity to construct an accurate internal representation of our current motion and orientation in space. Vestibular sensory signals are among those that may make an essential contribution to the construction of such ...
Paquette Caroline - - 2006
The head, containing the gravity sensors (vestibular system) and the visual system, must be stabilized in space to provide a steady reference. During walking, the head also needs to be free to move to allow scanning of surrounding objects and steering of locomotion. With aging, deteriorations in motor and sensory ...
Clément Gilles - - 2005
This review summarizes what has been learned from studies of human neurovestibular system in weightless conditions, including balance and locomotion, gaze control, vestibular-autonomic function and spatial orientation, and gives some examples of the potential Earth benefits of this research. Results show that when astronauts and cosmonauts return from space flight ...
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