Read by QxMD icon Read

gaze stabilization

Shane L Rogers, Craig P Speelman, Oliver Guidetti, Melissa Longmuir
We report the personal eye gaze patterns of people engaged in face-to-face getting acquainted conversation. Considerable differences between individuals are underscored by a stability of eye gaze patterns within individuals. Results suggest the existence of an eye-mouth gaze continuum. This continuum includes some people showing a strong preference for eye gaze, some with a strong preference for mouth gaze, and others distributing their gaze between the eyes and mouth to varying extents. Additionally, we found evidence of within-participant consistency not just for location preference but also for the duration of fixations upon the eye and mouth regions...
March 9, 2018: Scientific Reports
Yoshiko Izawa, Hisao Suzuki
Focal stimulation in the frontal eye field (FEF) evoked eye movements that were often accompanied by neck movements. Experiments were performed with concurrent recording of both movements in trained monkeys. We recorded neck forces under a head-restrained condition using a force-measuring system. With the system, we measured forces along the x, y, and z axes and torque about the z axis. Torque about the z axis that represented yaw rotation of the head was significantly affected by stimulation. We found that stimulation generated two types of motor actions of the eyes and neck...
March 7, 2018: Journal of Neurophysiology
Carl S Wilkins, Vaidehi S Dedania, Devon H Ghodasra, Mark W Johnson
PURPOSE: To report a rare case of vitreous cavity-Tenon capsule fistula formation after removal of a symptomatic hydrogel scleral buckle. METHODS: Case report. RESULTS: A 43-year-old man presented with chronic headache and involuntary gaze deviation for over 1 year after hydrogel scleral buckle surgery 25 years prior. After removal of the scleral buckle, the patient developed a fluid-filled inflation of the buckle capsule, surrounding a previously noted area of severe scleral thinning...
February 26, 2018: Retinal Cases & Brief Reports
Jana Goyens, Peter Aerts
The cyclic patterns of terrestrial animal locomotion are frequently perturbed in natural environments. The terrain can be complex or inclined, the substrate can move unexpectedly and animals can misjudge situations. Loosing stability due to perturbations increases the probability of capture by predators and decreases the chance of successful prey capture and winning intraspecific battles. When controlled corrective actions are necessary to negotiate perturbations, animals rely on their exteroceptive and proprioceptive senses to monitor the environment and their own body movements...
November 29, 2017: Zoology: Analysis of Complex Systems, ZACS
Alessandro Piras, Milena Raffi, Monica Perazzolo, Salvatore Squatrito
The optic flow visual input directly influences the postural control. The aim of the present study was to examine the relationship between visually induced heading perception and postural stability, using optic flow stimulation. The dots were accelerated to simulate a heading direction to the left or to the right of the vertical midline. The participants were instructed to indicate the perceived optic flow direction by making a saccade to the simulated heading direction. We simultaneously acquired electromyographyc and center of pressure (COP) signals...
February 10, 2018: Journal of Electromyography and Kinesiology
Anuj Kumar Neupane, Krithika Gururaj, Sujeet Kumar Sinha
BACKGROUND: Motion sickness is a complex autonomic phenomenon caused by the intersensory conflict among the balancing systems, resulting in a mismatch of signals between static physical conditions of the susceptible individual exposed to dynamic environment. PURPOSE: The present study was done to assess the sacculocollic reflex pathway and six semicircular canals in individuals susceptible to motion sickness. RESEARCH DESIGN: Standard group comparison was used...
February 2018: Journal of the American Academy of Audiology
Camille Grohé, Beatrice Lee, John J Flynn
The cheetah, Acinonyx jubatus, is the fastest living land mammal. Because of its specialized hunting strategy, this species evolved a series of specialized morphological and functional body features to increase its exceptional predatory performance during high-speed hunting. Using high-resolution X-ray computed micro-tomography (μCT), we provide the first analyses of the size and shape of the vestibular system of the inner ear in cats, an organ essential for maintaining body balance and adapting head posture and gaze direction during movement in most vertebrates...
February 2, 2018: Scientific Reports
Krunoslav Stingl, Tobias Peters, Torsten Strasser, Carina Kelbsch, Paul Richter, Helmut Wilhelm, Barbara Wilhelm
Pupillographic campimetry allows measuring the visual field objectively by analyzing the pupil response to perimetric stimuli. One of the drawbacks of this technique, similar to static perimetry, is the need of reliable fixation of the subject. By using stimulus sizes comparable to static perimetry and applying gaze tracking, we enable a retinotopic visual field examination regardless of fixation problems and with an increased stability and improved spatial resolution. Here, we present the results of applying the method in eight normal sighted subjects as well as in three patients suffering from diseases usually diagnosed by perimetry...
January 24, 2018: Biomedizinische Technik. Biomedical Engineering
Junhyung Park, Do-Heung Ko, Jingang Her, Jihea Woo
BACKGROUND: Cranio-cervical flexion exercise (CCFE) is a representative exercise that activates the deep muscles of neck pain patients. However, there are a lack of studies that propose specific exercise methods to examine the more effective activity level of the deep cervical flexor. OBJECTIVE: The objective of this study is to propose a more effective exercise method through effect comparison based on an optimal degree of mouth-opening, a mouth-open versus mouth-closed position, eye gaze, and body position change during CCFE...
December 29, 2017: Journal of Back and Musculoskeletal Rehabilitation
Samuel A Titchener, Mohit N Shivdasani, James B Fallon, Matthew A Petoe
Purpose: Shifting the region-of-interest within the input image to compensate for gaze shifts ("gaze compensation") may improve hand-eye coordination in visual prostheses that incorporate an external camera. The present study investigated the effects of eye movement on hand-eye coordination under simulated prosthetic vision (SPV), and measured the coordination benefits of gaze compensation. Methods: Seven healthy-sighted subjects performed a target localization-pointing task under SPV...
January 2018: Translational Vision Science & Technology
Jorge M Serrador, Brian M Deegan, Maria C Geraghty, Scott J Wood
Age-related loss of vestibular function can result in decrements in gaze stabilization and increased fall risk in the elderly. This study was designed to see if low levels of electrical stochastic noise applied transcutaneously to the vestibular system can improve a gaze stabilization reflex in young and elderly subject groups. Ocular counter-rolling (OCR) using a video-based technique was obtained in 16 subjects during low frequency passive roll tilts. Consistent with previous studies, there was a significant reduction in OCR gains in the elderly compared to the young group...
January 10, 2018: Scientific Reports
Ivo G Ros, Andrew A Biewener
Similar flight control principles operate across insect and vertebrate fliers. These principles indicate that robust solutions have evolved to meet complex behavioral challenges. Following from studies of visual and cervical feedback control of flight in insects, we investigate the role of head stabilization in providing feedback cues for controlling turning flight in pigeons. Based on previous observations that the eyes of pigeons remain at relatively fixed orientations within the head during flight, we test potential sensory control inputs derived from head and body movements during 90° aerial turns...
2017: Frontiers in Neuroscience
R Hermann, D Pelisson, O Dumas, Ch Urquizar, E Truy, C Tilikete
The vestibulo-ocular reflex maintains gaze stabilization during angular or linear head accelerations, allowing adequate dynamic visual acuity. In case of bilateral vestibular hypofunction, patients use saccades to compensate for the reduced vestibulo-ocular reflex function, with covert saccades occurring even during the head displacement. In this study, we questioned whether covert saccades help maintain dynamic visual acuity, and evaluated which characteristic of these saccades are the most relevant to improve visual function...
December 16, 2017: Cerebellum
Kelly M Cheever, Jane McDevitt, Ryan Tierney, W Geoffrey Wright
Vestibular and oculomotor testing is emerging as a valuable assessment in sport-related concussion (SRC). However, their usefulness for tracking recovery and guiding return-to-play decisions remains unclear. Therefore the purpose of this study was to evaluate their clinical usefulness for tracking SRC recovery. Vestibular and oculomotor assessments were used to measure symptom provocation in an acute group (n=21) concussed≤10 days, prolonged symptoms group (n=10) concussed ≥16 days (median=84 days), healthy group (n=58) no concussions in >6 months...
February 2018: International Journal of Sports Medicine
Philip R K Turnbull, John R Phillips
Virtual Reality (VR) headsets create immersion by displaying images on screens placed very close to the eyes, which are viewed through high powered lenses. Here we investigate whether this viewing arrangement alters the binocular status of the eyes, and whether it is likely to provide a stimulus for myopia development. We compared binocular status after 40-minute trials in indoor and outdoor environments, in both real and virtual worlds. We also measured the change in thickness of the ocular choroid, to assess the likely presence of signals for ocular growth and myopia development...
November 23, 2017: Scientific Reports
Phillip Aitken, Yiwen Zheng, Paul F Smith
The vestibular system is a sensory system that has evolved over millions of years to detect acceleration of the head, both rotational and translational, in three dimensions. One of its most important functions is to stabilize gaze during unexpected head movement; however, it is also important in the control of posture and autonomic reflexes. Theta rhythm is a 3-12 Hz oscillating EEG signal that is intimately linked to self-motion and is also known to be important in learning and memory. Many studies over the last two decades have shown that selective activation of the vestibular system, either using natural rotational or translational stimulation, or electrical stimulation of the peripheral vestibular system, can induce and modulate theta activity...
November 22, 2017: Journal of Neurophysiology
Diana Mihalache, Laurel A Gaeddert, Timothy D Sweeny
To determine where another person is looking, the visual system engages a process of emergent integration, pooling information across space from both the head and eyes. Gaze is dynamic, however, and in order to achieve a temporally stabilized metric of a person's direction of attention, this integrative process might also occur across time. Here, we tested and confirmed this prediction. Even when seen separately and in succession, the rotation of a head attracted the perceived gaze of a pair of eyes. This integration depended on temporal continuity-attraction decayed with longer delays between the face parts and prolonged viewing of the head reduced integration...
November 20, 2017: Journal of Experimental Psychology. Human Perception and Performance
Céline M Gravot, Alexander G Knorr, Stefan Glasauer, Hans Straka
The maintenance of visual acuity during active and passive body motion is ensured by gaze-stabilizing reflexes that aim at minimizing retinal image slip. For the optokinetic reflex (OKR), large-field visual motion of the surround forms the essential stimulus that activates eye movements. Properties of the moving visual world influence cognitive motion perception and the estimation of visual image velocity. Therefore, the performance of brainstem-mediated visuo-motor behaviors might also depend on image scene characteristics...
November 15, 2017: Journal of Experimental Biology
Sung-Hee Kim, Ji-Soo Kim
The middle cerebellar peduncle (MCP) is a major conduit for cortico-ponto-cerebellar fibers that convey information related to eye movements. This study aims to elucidate eye movement abnormalities that arise from lesions confined to the MCP. In 23 patients with acute strokes restricted to unilateral MCPs, we investigated the clinical features and ocular motor findings including spontaneous nystagmus, saccades, smooth pursuit, ocular tilt reaction, and head impulse tests. Bithermal caloric tests and audiometry were also performed...
November 11, 2017: Acta Neurologica Belgica
Lee A Tan, K Daniel Riew, Vincent C Traynelis
The goals of cervical deformity surgery include deformity correction, restoration of horizontal gaze, decompression of neural elements, spinal stabilization with a biomechanically sound construct, and meticulous arthrodesis technique to prevent pseudoarthrosis and minimizing surgical complications. Many different surgical options exist, but selecting the correct approach that ensures the optimal clinical outcome can be challenging and often controversial. In this last part of the cervical deformity review series, various posterior deformity correction techniques are discussed in detail, along with an overview of surgical outcome and postoperative complications...
December 1, 2017: Neurosurgery
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"