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https://www.readbyqxmd.com/read/28417834/adaptive-changes-in-the-perception-of-fast-and-slow-movement-at-different-head-positions
#1
Roberto Panichi, Chiara Occhigrossi, Aldo Ferraresi, Mario Faralli, Marco Lucertini, Vito E Pettorossi
BACKGROUND: This paper examines the subjective sense of orientation during asymmetric body rotations in normal subjects. METHODS: Self-motion perception was investigated in 10 healthy individuals during asymmetric whole-body rotation with different head orientations. Both on-vertical axis and off-vertical axis rotations were employed. Subjects tracked a remembered earth-fixed visual target while rotating in the dark for four cycles of asymmetric rotation (two half-sinusoidal cycles of the same amplitude, but of different duration)...
May 1, 2017: Aerospace Medicine and Human Performance
https://www.readbyqxmd.com/read/28224454/effects-of-sustained-otolith-only-stimulation-on-post-rotational-nystagmus
#2
Aasef G Shaikh, David Solomon
Constant velocity rotations in darkness evoke vestibulo-ocular reflex in form of pre- and post-rotational nystagmus under cerebellar supervision. Reorientation of the head with respect to gravity, stimulating otolith and semicircular canal, during post-rotational phase rapidly suppresses the post-rotational nystagmus. We asked if pure otolith stimulation without semicircular canal signal is sufficient for the suppression of post-rotational nystagmus. The experimental paradigm comprised of on-axis rotations in the horizontal plane when the subject was sitting upright, followed by a novel stimulus that combined off-axis centrifugation in the horizontal plane with amplitude matched, yet out-of-phase, on-axis horizontal rotation-double centrifugation...
February 21, 2017: Cerebellum
https://www.readbyqxmd.com/read/28176802/ocular-reflex-phase-during-off-vertical-axis-rotation-in-humans-is-modified-by-head-turn-on-trunk-position
#3
Samantha B Douglas, Gilles Clément, Pierre Denise, Scott J Wood
Constant velocity Off-Vertical Axis Rotation (OVAR) imposes a continuously varying orientation of the head and body relative to gravity, which generates a modulation of horizontal (conjugate and vergence), vertical, and torsional eye movements. We introduced the head-turn-on-trunk paradigm during OVAR to examine the extent to whether the modulation of these ocular reflexes is mediated by graviceptors in the head, i.e., otoliths, versus other body graviceptors. Ten human subjects were rotated in darkness about their longitudinal axis 20° off-vertical at a constant velocity of 45 and 180°/s, corresponding to 0...
February 8, 2017: Scientific Reports
https://www.readbyqxmd.com/read/27505840/scalable-screen-size-enlargement-by-multi-channel-viewing-zone-scanning-holography
#4
Yasuhiro Takaki, Mitsuki Nakaoka
Viewing-zone scanning holographic displays can enlarge both the screen size and the viewing zone. However, limitations exist in the screen size enlargement process even if the viewing zone is effectively enlarged. This study proposes a multi-channel viewing-zone scanning holographic display comprising multiple projection systems and a planar scanner to enable the scalable enlargement of the screen size. Each projection system produces an enlarged image of the screen of a MEMS spatial light modulator. The multiple enlarged images produced by the multiple projection systems are seamlessly tiled on the planar scanner...
August 8, 2016: Optics Express
https://www.readbyqxmd.com/read/26827718/translational-otolith-ocular-reflex-during-off-vertical-axis-rotation-in-humans
#5
Gilles Clément, Scott J Wood
Two characteristics of otolith-ocular responses - linear vestibulo-ocular reflex and vergence - were examined during constant velocity off-vertical axis rotation (OVAR) in the dark. Sixteen subjects were rotated about their longitudinal axis when tilted 30° relative to the direction of gravity. Rotational velocities were 36 and 288/s corresponding to frequencies of 0.1 and 0.8Hz, respectively. Subjects were asked to imagine stationary targets located at 0.5m, 1m, and 2m in the straight-ahead direction. Binocular eye movements were recorded in the dark using infrared videography...
March 11, 2016: Neuroscience Letters
https://www.readbyqxmd.com/read/26597305/plasticity-of-the-human-vestibulo-ocular-reflex-during-off-vertical-axis-rotation
#6
Masatoshi Akutsu, Akemi Sugita-Kitajima, Koshi Mikami, Izumi Koizuka
OBJECTIVE: We investigated whether adaptive plasticity of the vestibulo-ocular reflex in humans occurs in response to visual-vestibular conflict stimulation during rotation about a 30° incline (off-vertical earth axis rotation, OVAR). METHODS: Subjects were 26 healthy adults (17 males and 9 females), ranging in age from 22 to 33 years (mean: 24.4) with no history of neurotological symptoms. Each testing session consisted of a pre-test, an adaptation period, and a post-test...
August 2016: Auris, Nasus, Larynx
https://www.readbyqxmd.com/read/26347442/vestibular-disorders-in-children-with-congenital-cytomegalovirus-infection
#7
Sophie Bernard, Sylvette Wiener-Vacher, Thierry Van Den Abbeele, Natacha Teissier
BACKGROUND: Congenital cytomegalovirus (CMV) infection is the leading infectious cause of neurologic disabilities and sensorineural hearing loss in children. Sensorineural hearing loss prevalence in CMV suggests a viral tropism for the inner ear. Vestibular disorders induced by CMV infection are underestimated. This is the largest and most thorough study to assess the incidence of vestibular disorders and their correlation with hearing thresholds in children with CMV. METHODS: This retrospective study assessed a cohort of 52 children with congenital CMV infection and sensorineural impairment who received a complete hearing and vestibular assessment...
October 2015: Pediatrics
https://www.readbyqxmd.com/read/26288211/-the-complete-elimination-of-the-episodes-of-benign-positional-paroxysmal-vertigo-in-a-patient-with-the-involvement-of-the-posterior-semicircular-canal-following-the-eccentric-rotation-test
#8
E I Matsnev, E E Sigaleva
The objective of the present study was the clinical and neurophysiological analysis of the observations of a 42 year-old female patient suffering from benign paroxysmalpositional dizziness (BPPD) associated with the lesion of the posterior semicircular canal. The dynamic evaluation of the utricular function was performed during eccentric rotation of the patient in the vestibulometric chair at a speed of 300 degrees. The chair together with the patients was atomatically displaced during the rotation 3.5--4.0 cm to the right or left off the vertical axis, and the error in subjective perception of the deviation from the vertical was estimated...
2015: Vestnik Otorinolaringologii
https://www.readbyqxmd.com/read/25882474/less-sickness-with-more-motion-and-or-mental-distraction
#9
RANDOMIZED CONTROLLED TRIAL
Jelte E Bos
BACKGROUND: Motion sickness may reduce passenger comfort and crew performance. Countermeasures are dominated by medication with specific and often undesirable side effects. OBJECTIVE: To shown that sickness due to motion can be reduced by adding an inherent non-sickening vibration and by mental distraction. METHODS: Eighteen blindfolded subjects were exposed to 20 minutes of off-vertical axis rotation (OVAR). Vibration was added by means of a head rest...
2015: Journal of Vestibular Research: Equilibrium & Orientation
https://www.readbyqxmd.com/read/25827332/preserved-otolith-organ-function-in-caspase-3-deficient-mice-with-impaired-horizontal-semicircular-canal-function
#10
Patrick A Armstrong, Scott J Wood, Naoki Shimizu, Kael Kuster, Adrian Perachio, Tomoko Makishima
Genetically engineered mice are valuable models for elucidation of auditory and vestibular pathology. Our goal was to establish a comprehensive vestibular function testing system in mice using: (1) horizontal angular vestibulo-ocular reflex (hVOR) to evaluate semicircular canal function and (2) otolith-ocular reflex (OOR) to evaluate otolith organ function and to validate the system by characterizing mice with vestibular dysfunction. We used pseudo off-vertical axis rotation to induce an otolith-only stimulus using a custom-made centrifuge...
June 2015: Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation Cérébrale
https://www.readbyqxmd.com/read/25617456/streamwise-vortices-destabilize-swimming-bluegill-sunfish-lepomis-macrochirus
#11
Anabela Maia, Alex P Sheltzer, Eric D Tytell
In their natural environment, fish must swim stably through unsteady flows and vortices, including vertical vortices, typically shed by posts in a flow, horizontal cross-flow vortices, often produced by a step or a waterfall in a stream, and streamwise vortices, where the axis of rotation is aligned with the direction of the flow. Streamwise vortices are commonly shed by bluff bodies in streams and by ships' propellers and axial turbines, but we know little about their effects on fish. Here, we describe how bluegill sunfish use more energy and are destabilized more often in flow with strong streamwise vorticity...
March 2015: Journal of Experimental Biology
https://www.readbyqxmd.com/read/25446357/dynamic-characteristics-of-otolith-ocular-response-during-counter-rotation-about-dual-yaw-axes-in-mice
#12
N Shimizu, S Wood, K Kushiro, S Yanai, A Perachio, T Makishima
The central vestibular system plays an important role in higher neural functions such as self-motion perception and spatial orientation. Its ability to store head angular velocity is called velocity storage mechanism (VSM), which has been thoroughly investigated across a wide range of species. However, little is known about the mouse VSM, because the mouse lacks typical ocular responses such as optokinetic after nystagmus or a dominant time constant of vestibulo-ocular reflex for which the VSM is critical. Experiments were conducted to examine the otolith-driven eye movements related to the VSM and verify its characteristics in mice...
January 29, 2015: Neuroscience
https://www.readbyqxmd.com/read/25148589/preoperative-decision-making-in-the-treatment-of-high-angle-vertical-femoral-neck-fractures-in-young-adult-patients-an-expert-opinion-survey-of-the-orthopaedic-trauma-association-s-ota-membership
#13
Kevin Luttrell, Michael Beltran, Cory A Collinge
OBJECTIVE: To identify the current implant and diagnostic imaging preferences among orthopaedic trauma experts for the treatment of high-energy vertical femoral neck fractures in young adult patients. DESIGN: Web-based survey. SETTING: Not available. PARTICIPANTS: Active members of the OTA. METHODS: A cross-sectional expert opinion survey was administered to the active members of the OTA to determine their preferences for implant use and imaging in the surgical treatment of a vertical femoral neck fracture in a young adult patient (e...
September 2014: Journal of Orthopaedic Trauma
https://www.readbyqxmd.com/read/24694558/pre-operative-decision-making-in-the-treatment-of-high-angle-vertical-femoral-neck-fractures-in-young-adult-patients
#14
Kevin Luttrell, Michael Beltran, Cory Collinge
OBJECTIVE: To identify the current implant and diagnostic imaging preferences among orthopedic trauma experts for the treatment of high-energy vertical femoral neck fractures in young adult patients. DESIGN: Web-based survey SETTING:: N/A PARTICIPANTS:: Active members of the Orthopaedic Trauma Association (OTA) METHODS:: A cross sectional expert opinion survey was administered to active members of the OTA to determine their preferences for implant use and imaging in the surgical treatment of a vertical femoral neck fracture in a young adult patient (e...
April 1, 2014: Journal of Orthopaedic Trauma
https://www.readbyqxmd.com/read/24602977/is-there-a-relationship-between-odors-and-motion-sickness
#15
A C Paillard, M Lamôré, O Etard, J-L Millot, L Jacquot, P Denise, G Quarck
The aim of this study was to evaluate the relationship between olfaction and motion sickness. A sample of 18 participants was recruited and submitted to three sessions of nauseogenic stimulations: off vertical axis rotation (OVAR), performed under conditions of olfactory stimulation with limonene (pleasant odor), petrol (unpleasant odor) or distilled water (as a control). Motion sickness was assessed before, during and after each OVAR session. In addition, participants were asked to evaluate the intensity and hedonic valence of four odors (geraniol, limonene, butanol, petrol) as well as distilled water (as a control) before and after each OVAR session...
April 30, 2014: Neuroscience Letters
https://www.readbyqxmd.com/read/24515145/reconfigurable-optical-null-based-on-counter-rotating-zernike-plates-for-test-of-aspheres
#16
Shanyong Chen, Chunyu Zhao, Yifan Dai, Shengyi Li
In off-axis subapertures of most aspheres, astigmatism and coma dominate the aberrations with approximately quadratic and linear increase as the off-axis distance increases. A pair of counter-rotating Zernike plates is proposed to generate variable amount of Zernike terms Z4 and Z6, correcting most of the astigmatism and coma for subapertures located at different positions on surfaces of various aspheric shapes. The residual subaperture aberrations are then reduced within the vertical dynamic range of measurement of the interferometer...
January 27, 2014: Optics Express
https://www.readbyqxmd.com/read/24430025/otolith-signals-contribute-to-inter-individual-differences-in-the-perception-of-gravity-centered-space
#17
C Cian, P A Barraud, A C Paillard, S Hidot, P Denise, J Ventre-Dominey
The aim of the present study was to investigate (1) the relative contribution of the egocentric reference as well as body orientation perception to visual horizon percept during tilt or during increased gravito-inertial acceleration (GiA, hypergravity environment) conditions and (2) the role of vestibular signals in the inter-individual differences observed in these perceptual modalities. Perceptual estimates analysis showed that backward tilt induced (1) an elevation of the visual horizon, (2) an elevation of the egocentric estimation (visual straight ahead) and (3) an overestimation of body tilt...
March 2014: Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation Cérébrale
https://www.readbyqxmd.com/read/24146701/kinematic-and-kinetic-analysis-of-two-gymnastics-acrobatic-series-to-performing-the-backward-stretched-somersault
#18
Bessem Mkaouer, Monèm Jemni, Samiha Amara, Helmi Chaabène, Zouhair Tabka
Back swing connections during gymnastics acrobatic series considerably influence technical performance and difficulties, particularly in the back somersault. The aim of this study was to compare the take-off's kinetic and kinematic variables between two acrobatic series leading to perform the backward stretched somersault (also called salto): round-off, flic-flac to stretched salto versus round-off, tempo-salto to stretched salto. Five high level male gymnasts (age 23.17 ± 1.61 yrs; body height 1.65 ± 0.05 m; body mass 56...
2013: Journal of Human Kinetics
https://www.readbyqxmd.com/read/23880368/evaluation-of-the-vestibulo-ocular-reflex-using-sinusoidal-off-vertical-axis-rotation-in-patients-with-canal-paresis
#19
Akemi Sugita-Kitajima, Izumi Koizuka
OBJECTIVE: The vestibulo-ocular reflex (VOR) was studied to determine the utility of off-vertical axis rotation (OVAR) in evaluating vestibular function in patients with canal paresis (CP). Our goal was to determine whether there is any correlation between caloric responses and sinusoidal rotatory responses. METHODS: Subjects were rotated in a sinusoidal pattern with eyes open in complete darkness. Frequencies of 0.4 and 0.8Hz with a maximum angular velocity of 60°/s at either earth-vertical axis rotation (EVAR) or OVAR were used...
February 2014: Auris, Nasus, Larynx
https://www.readbyqxmd.com/read/23872774/in-plane-switching-of-vertically-aligned-negative-liquid-crystals-for-high-transmittance-and-wide-viewing-angle
#20
Jung-Wook Kim, Dong Han Song, Ki-Han Kim, Sung-Tae Shin, Tae-Hoon Yoon
We propose a method for in-plane switching of vertically aligned negative liquid crystals (LCs) for high transmittance and wide viewing angle. By applying an in-plane electric field using a double-layered electrode structure, LC molecules can be rotated by the vertical as well as the in-plane components of the applied field over the entire region so that high transmittance can be achieved. The threshold voltage difference can be obtained simply by varying the electrode structure, which can reduce the off-axis gamma shift in a multidomain vertical alignment LC cell...
July 20, 2013: Applied Optics
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