Eye Movement Measurements: Methods and procedures for recording EYE MOVEMENTS.Eye Movements: Voluntary or reflex-controlled movements of the eye.Movement: The act, process, or result of passing from one place or position to another. It differs from LOCOMOTION in that locomotion is restricted to the passing of the whole body from one place to another, while movement encompasses both locomotion but also a change of the position of the whole body or any of its parts. Movement may be used with reference to humans, vertebrate and invertebrate animals, and microorganisms. Differentiate also from MOTOR ACTIVITY, movement associated with behavior.Eye: The organ of sight constituting a pair of globular organs made up of a three-layered roughly spherical structure specialized for receiving and responding to light.Saccades: An abrupt voluntary shift in ocular fixation from one point to another, as occurs in reading.Pursuit, Smooth: Eye movements that are slow, continuous, and conjugate and occur when a fixed object is moved slowly.Fixation, Ocular: The positioning and accommodation of eyes that allows the image to be brought into place on the FOVEA CENTRALIS of each eye.Sleep, REM: A stage of sleep characterized by rapid movements of the eye and low voltage fast pattern EEG. It is usually associated with dreaming.Electrooculography: Recording of the average amplitude of the resting potential arising between the cornea and the retina in light and dark adaptation as the eyes turn a standard distance to the right and the left. The increase in potential with light adaptation is used to evaluate the condition of the retinal pigment epithelium.Photic Stimulation: Investigative technique commonly used during ELECTROENCEPHALOGRAPHY in which a series of bright light flashes or visual patterns are used to elicit brain activity.Head Movements: Voluntary or involuntary motion of head that may be relative to or independent of body; includes animals and humans.Ocular Motility Disorders: Disorders that feature impairment of eye movements as a primary manifestation of disease. These conditions may be divided into infranuclear, nuclear, and supranuclear disorders. Diseases of the eye muscles or oculomotor cranial nerves (III, IV, and VI) are considered infranuclear. Nuclear disorders are caused by disease of the oculomotor, trochlear, or abducens nuclei in the BRAIN STEM. Supranuclear disorders are produced by dysfunction of higher order sensory and motor systems that control eye movements, including neural networks in the CEREBRAL CORTEX; BASAL GANGLIA; CEREBELLUM; and BRAIN STEM. Ocular torticollis refers to a head tilt that is caused by an ocular misalignment. Opsoclonus refers to rapid, conjugate oscillations of the eyes in multiple directions, which may occur as a parainfectious or paraneoplastic condition (e.g., OPSOCLONUS-MYOCLONUS SYNDROME). (Adams et al., Principles of Neurology, 6th ed, p240)Reflex, Vestibulo-Ocular: A reflex wherein impulses are conveyed from the cupulas of the SEMICIRCULAR CANALS and from the OTOLITHIC MEMBRANE of the SACCULE AND UTRICLE via the VESTIBULAR NUCLEI of the BRAIN STEM and the median longitudinal fasciculus to the OCULOMOTOR NERVE nuclei. It functions to maintain a stable retinal image during head rotation by generating appropriate compensatory EYE MOVEMENTS.Sleep Stages: Periods of sleep manifested by changes in EEG activity and certain behavioral correlates; includes Stage 1: sleep onset, drowsy sleep; Stage 2: light sleep; Stages 3 and 4: delta sleep, light sleep, deep sleep, telencephalic sleep.Nystagmus, Optokinetic: Normal nystagmus produced by looking at objects moving across the field of vision.Motion Perception: The real or apparent movement of objects through the visual field.Convergence, Ocular: The turning inward of the lines of sight toward each other.Reaction Time: The time from the onset of a stimulus until a response is observed.Oculomotor Muscles: The muscles that move the eye. Included in this group are the medial rectus, lateral rectus, superior rectus, inferior rectus, inferior oblique, superior oblique, musculus orbitalis, and levator palpebrae superioris.Psychomotor Performance: The coordination of a sensory or ideational (cognitive) process and a motor activity.Wakefulness: A state in which there is an enhanced potential for sensitivity and an efficient responsiveness to external stimuli.Macaca mulatta: A species of the genus MACACA inhabiting India, China, and other parts of Asia. The species is used extensively in biomedical research and adapts very well to living with humans.Nystagmus, Pathologic: Involuntary movements of the eye that are divided into two types, jerk and pendular. Jerk nystagmus has a slow phase in one direction followed by a corrective fast phase in the opposite direction, and is usually caused by central or peripheral vestibular dysfunction. Pendular nystagmus features oscillations that are of equal velocity in both directions and this condition is often associated with visual loss early in life. (Adams et al., Principles of Neurology, 6th ed, p272)Nystagmus, Physiologic: Involuntary rhythmical movements of the eyes in the normal person. These can be naturally occurring as in end-position (end-point, end-stage, or deviational) nystagmus or induced by the optokinetic drum (NYSTAGMUS, OPTOKINETIC), caloric test, or a rotating chair.Visual Perception: The selecting and organizing of visual stimuli based on the individual's past experience.Sleep: A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility.Vision, Binocular: The blending of separate images seen by each eye into one composite image.Eye Diseases: Diseases affecting the eye.Abducens Nerve: The 6th cranial nerve which originates in the ABDUCENS NUCLEUS of the PONS and sends motor fibers to the lateral rectus muscles of the EYE. Damage to the nerve or its nucleus disrupts horizontal eye movement control.Eye Movement Desensitization Reprocessing: A technique that induces the processing of disturbing memories and experiences, by stimulating neural mechanisms that are similar to those activated during REM sleep. The technique consists of eye movements following side-to-side movements of the index and middle fingers, or the alternate tapping of the hands on the knees. This procedure triggers the processing of information, thus facilitating the connection of neural networks.Rotation: Motion of an object in which either one or more points on a line are fixed. It is also the motion of a particle about a fixed point. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Visual Fields: The total area or space visible in a person's peripheral vision with the eye looking straightforward.Oculomotor Nerve: The 3d cranial nerve. The oculomotor nerve sends motor fibers to the levator muscles of the eyelid and to the superior rectus, inferior rectus, and inferior oblique muscles of the eye. It also sends parasympathetic efferents (via the ciliary ganglion) to the muscles controlling pupillary constriction and accommodation. The motor fibers originate in the oculomotor nuclei of the midbrain.Electroencephalography: Recording of electric currents developed in the brain by means of electrodes applied to the scalp, to the surface of the brain, or placed within the substance of the brain.Attention: Focusing on certain aspects of current experience to the exclusion of others. It is the act of heeding or taking notice or concentrating.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Reading

*  Sentence spacing studies - Wikipedia
Kolers, Paul A.; Duchinsky, Robert; Ferguson, Dennis C. (1981). "Eye Movement Measurement of Readability of CRT Displays". ... The normal, easy, left-to-right movement of the eye is slowed down simply because of this separation; further, the short ... The eye also tends to be confused by a feeling of vertical emphasis, that is, an up & down movement, induced by the relative ... This movement is further emphasized by those "rivers" of white which are the inseparable & ugly accompaniment of all carelessly ...
*  Sentence spacing - Wikipedia
Kolers, Paul A.; Duchinsky, Robert; Ferguson, Dennis C. (1981). "Eye Movement Measurement of Readability of CRT Displays". ...
*  Tom Cornsweet - Wikipedia
Cornsweet, T.N. (1958). "New technique for the measurement of small eye movements". Journal of the Optical Society of America. ... The Purkinje-image method of recording eye position. In: Eye movements and psychological processes, Monty and Senders, eds., ... His 1955 Ph.D. dissertation in experimental psychology involved small movements of the eye. Cornsweet was an assistant ... Cornsweet, T.N. (1956). "Determination of the stimuli for involuntary drifts and saccadic eye movements". Journal of the ...
*  Tullio's Phenomonenon
Quantitative measurements of eye movements in a patient with Tullio Phenomenon. J. Vest Res, 6, 255-259, 1996 ... Tullio-test: Output measurement The biggest variable of all is output measurement. The most common method is simply to ask the ... Tullio (1929) originally investigated sound-induced eye and head movement in pigeons. He made openings in the semicircular ... Output measurement Tullio test: Sound generators Starting with sound generators, audiometers (hearing testing machines) are the ...
*  Search of: Cephalic Disorders - List Results - ClinicalTrials.gov
Other: movements of the upper limb, the gripping force, muscle activity and eye-cephalic subject movement measurements ... Gravity induced changes in oculo-manual coordination measured by the latency (ms) of anticipatory eye movement measurement with ... Pain Scores (at movement and at rest). 47. All. 8 Years to 17 Years (Child). NCT02669004. scoliosis. June 2015. January 2016. ... Influence of Gravity on Dexterity, Hand-eye Coordination and Perception of Orientation and Distances. *Healthy Volunteers ...
*  Eye tracking - Wikipedia
Measurements with tight-fitting contact lenses have provided extremely sensitive recordings of eye movement, and magnetic ... AttentionTracking Eye movement Eye movement in language reading Eye movement in music reading Eye Tracking Device Fovea ... or the motion of an eye relative to the head. An eye tracker is a device for measuring eye positions and eye movement. Eye ... A camera focuses on one or both eyes and records eye movement as the viewer looks at some kind of stimulus. Most modern eye- ...
*  Saccade - Wikipedia
Eye movement measurements are also used to investigate psychiatric disorders. For example, ADHD is characterized by an increase ... Chronostasis Eye movement Eye movement in language reading Eye movement in music reading Eye tracking Frame rate Frontal eye ... Since the VOR can actually rotate the eyes around the line of sight, combined eye and head movements do not always obey ... Due to saccadic masking, the eye/brain system not only hides the eye movements from the individual but also hides the evidence ...
*  Electrooculography - Wikipedia
In practice, the measurement is similar to eye movement recordings (see above). The patient is asked to switch eye position ... To measure eye movement, pairs of electrodes are typically placed either above and below the eye or to the left and right of ... Primary applications are in ophthalmological diagnosis and in recording eye movements. Unlike the electroretinogram, the EOG ... Assuming that the resting potential is constant, the recorded potential is a measure of the eye's position. The eye acts as a ...
*  Meniere's disease Symptoms - Mayo Clinic
Measurements of involuntary eye movements in response to this stimulation are performed using a special pair of video goggles. ... Video head impulse test (vHIT). This newer test uses video to measure eye reactions to abrupt movement. While you focus on a ... Rotary-chair testing. Like a VNG, this measures inner ear function based on eye movement. You sit in a computer-controlled ... Balance-related sensors in the inner ear are linked to muscles that control eye movement. This connection enables you to move ...
*  Characterization of Executive Functions and Patterns of Eye Movements in Children With Developmental Disabilities - Full Text...
The fine measurement of eye movements may shed light on the underlying mechanisms of specific disorders, and point to abnormal ... Eye movements will be measured using an infra-red video camera produced by ISCAN inc. the following visual stimuli will be ... It will also assess the pattern of eye movements in response to various visual stimuli in these populations. The main purpose ... The purpose of this study is to characterize the profile of executive functions and eye movements in several populations of ...
*  Plus it
After selection of the measurement location, the DVA is able to track the vessels during eye movements within the measurement ... baseline measurements of retinal blood flow parameters were performed in the right eye. Thereafter, all measurements were ... Only recently, however, retinal blood velocity measurements in human eyes based on optical coherence tomography were introduced ... Retinal blood flow was assessed by combining velocity measurements using laser Doppler velocimetry and diameter measurements ...
*  Cross-over Comparison of Gabapentin and Memantine as Treatment for Acquired Nystagmus - Full Text View - ClinicalTrials.gov
The study entails careful measurements of visual acuity and precise measurements of eye movements, using a contact lens device ... Percent Change in Median Eye Speed [ Time Frame: After 2 weeks of therapy, for both drugs ]. Median eye speed during attempted ... NIHR01EY06717 ( Other Identifier: National Eye Institute ). NIH R01 EYO6717 ( Other Grant/Funding Number: National Eye ... MedlinePlus related topics: Eye Care Drug Information available for: Memantine Memantine hydrochloride Gabapentin Gabapentin ...
*  Changes in angle of optic nerve and angle of ocular orbit with increasing age in Japanese children | British Journal of...
However, children have difficulty controlling their eye movements, so measurements may differ from the actual opening angle of ... The third limitation is that we did not determine the eye position and eye movements before the CT recordings. The fourth ... This site is closely associated with eye movements and eye alignment.. Although the relationship between the morphology of the ... Measurements were performed on axial CT images that included the entire optic nerve of both eyes. The opening angle of the ...
*  list MeSH keywords | AACknowledge
eye movement measurements (4) eye movements (9) facial muscles (1) family (13) family relations (2) ... difficulties communication interventions congenital dementia dysarthria dysphagia dysphasia dyspraxia education employment eye ...
*  Frontiers | Eye movements reveal sexually dimorphic deficits in children with fetal alcohol spectrum disorder | Neuroscience
Conclusions: These data support the hypothesis that children with FASD exhibit specific deficits in eye movement control and ... Moreover, prenatal alcohol exposure may have a sexually dimorphic impact on eye movement metrics, with males and females ... Therefore, we hypothesized that eye movement measures will show sexually dimorphic results.Methods: Children (aged 5-18 years) ... Therefore, we hypothesized that eye movement measures will show sexually dimorphic results. Methods: Children (aged 5-18 years ...
*  Eye Tracking and Web Usability: A Good Fit? | UX Magazine
... but beside that his experience is not interrupted or burdened by eye tracking. In fact, the measurement of eye-movement ... Eye movement is tightly linked to attention. To summarize the corpus of research done to date[6], you cannot move your eyes ... Precise Time Measurement. The mechanics of eye tracking measurement demand that the equipment be sophisticated enough to ... Measuring eye-movement behavior, which participants cannot alter as easily as verbal or survey responses, is one way to control ...
*  Eye tracking on the ISS - Wikipedia
The Eye Tracking Device (ETD) is a headmounted device, designed for measurement of three-dimensional eye and head movements ... The tracker permits comprehensive measurement of eye movement (three degrees of freedom) and optionally head movement (six ... 549-560 High image rate eye movement measurement A.H.Clarke, C.Steineke and H.Emanuel; "Archived copy" (PDF). Archived from the ... EYE TRACKING DEVICE) EXPERIMENT ESA; Measurement by Eye Tracking Device in orientation of the Listing's plane German Aerospace ...
*  Ocular Torsion during Voluntary Blinks in Humans | IOVS | ARVO Journals
To obtain reliable measurement of torsional eye movements with dual search coils during blinks, modification of the annulus is ... The initial eye movement associated with closing the eyes consisted of a pulselike movement in a direction that consistently ... Torsional and Vertical Eye Movements during Head Tilt Dynamic Characteristics. Cross-Coupled Eye Movement Supports Neural ... The initial eye movement, which emerged before the eye was closed, was found to be nasal- and downward. Bour et al. 3 measured ...
*  Morbus meniere | definition of Morbus meniere by Medical dictionary
Since the eyes and ears work together through the nervous system to coordinate balance, measurement of eye movements can be ... are placed near the eyes. Warm and cool water or air are gently introduced into the each ear canal and eye movements are ...
*  VOG - Wikipedia
... an eye-movement measurement technique Voices of Gotham, a choir based in New York City, United States Volgograd International ...
*  KIT - Institut für Technik der InformationsverarbeitungInstitut - Mitarbeiter - Stork, Wilhelm
Development of a camera based system for the measurement of blood pulse induced eye movements.. Eix, I.; Stork, W.. 2004. ... Non-Invasive Polarimetric Glucose Measurement System For Eye Phantoms And In-Vivo Measurement Requirements.. Rawer, R.; Vollmer ... Non invasive polarimetric measurement of glucose concentration in the anterior chamber of the eye.. Rawer, R.; Stork, W.; ... Non-contact measurement of the intraocular pressure (IOP) through stimulation and measurement of microvibrations of the human ...
*  Eye Movement Disorders | Nystagmus | Strabismus | MedlinePlus
... where the eyes point in different directions, and nystagmus, which causes rapid eye movements. ... Learn about eye movement disorders, such as strabismus, ... Strabismus Measurements (American Association for Pediatric ... Nystagmus - fast, uncontrollable movements of the eyes, sometimes called "dancing eyes". Some eye movement disorders are ... Treatments include glasses, patches, eye muscle exercises, and surgery. There is no cure for some kinds of eye movement ...
*  Henry Metz - Wikipedia
Much of his early research concerned eye movements and strabismus, including saccadic velocity measurements and use of ... During the late 1990s Metz maintained private practice in Rochester and at The Eye Specialists Center in Illinois, and served ... 1978-1993, Chair of the Department of Ophthalmology at the University of Rochester Eye Institute Editor-in-Chief of the Journal ... Metz HS (1976). "Saccadic velocity measurements in internuclear ophthalmoplegia". Am J Ophthalmol. 81 (3): 296-9. PMID 1258953 ...
*  JoVE | Peer Reviewed Scientific Video Journal - Methods and Protocols
The OKR involves slow stimulus-following movements of eyes alternated with rapid resetting saccades. The measurement of this ... Eye movement monitoring procedures begin with the placement of the eye tracker on the participant, and setup of the head and ... Eye movement monitoring (eye tracking) provides a tool by which memory can be probed without asking participants to comment on ... Neuroscience, Issue 42, eye movement monitoring, eye tracking, memory, aging, amnesia, visual processing ...

Voluntary Parenthood League: The Voluntary Parenthood League (VPL) was an organization that advocated for contraception during the birth control movement in the United States. The VPL was founded in 1919 by Mary Dennett.Guiding Eyes for the Blind: Yorktown Heights, New YorkSaccade: A saccade ( , French for jerk) is quick, simultaneous movement of both eyes between two phases of fixation in the same direction.Cassin, B.Marion ClignetElectrooculographyFall Heads Roll: Fall Heads Roll is an album by The Fall, released in 2005. It was recorded at Gracieland Studios in Rochdale, UK and Gigantic Studios in New York, NY.Conjugate gaze palsyVision in fishes: Vision is an important sensory system for most species of fish. Fish eyes are similar to terrestrial vertebrates like birds and mammals, but have a more spherical lens.Optokinetic reflexBiological motion: Biological motion is a term used by social and cognitive neuroscientists to refer to the unique visual phenomenon of a moving, animate object. Often, the stimuli used in biological motion experiments are just a few moving dots that reflect the motion of some key joints of the moving organism.Convergence of measures: In mathematics, more specifically measure theory, there are various notions of the convergence of measures. For an intuitive general sense of what is meant by convergence in measure, consider a sequence of measures μn on a space, sharing a common collection of measurable sets.Inferior rectus muscle: The inferior rectus muscle is a muscle in the orbit.NystagmusAlexander's law: Jacobson GP et al. Alexander's law revisited.Non-rapid eye movement sleepBinocular vision: Binocular vision is vision in which creatures having two eyes use them together. The word binocular comes from two Latin roots, bini for double, and oculus for eye.Neuro-ophthalmology: Neuro-ophthalmology is an academically-oriented subspecialty that merges the fields of neurology and ophthalmology, often dealing with complex systemic diseases that have manifestations in the visual system. Neuro-ophthalmologists initially complete a residency in either neurology or ophthalmology, then do a fellowship in the complementary field.Abducens nucleus: The abducens nucleus is the originating nucleus from which the abducens nerve (VI) emerges - a cranial nerve nucleus. This nucleus is located beneath the fourth ventricle in the caudal portion of the pons, medial to the sulcus limitans.Traumatic memories: The management of traumatic memories is important when treating mental health disorders such as post traumatic stress disorder. Traumatic memories can cause life problems even to individuals who do not meet the diagnostic criteria for a mental health disorder.Doxanthrine: Doxanthrine is a synthetic compound which is a potent and selective full agonist for the dopamine D1 receptor. Doxanthrine has been shown to be orally active in producing contralateral rotation in the 6-hydroxy-dopamine rat model of Parkinson's disease.Meridian (perimetry, visual field): Meridian (plural: "meridians") is used in perimetry and in specifying visual fields. According to IPS Perimetry Standards 1978 (2002): "Perimetry is the measurement of [an observer's] visual functions ...Oculomotor nucleus: The fibers of the oculomotor nerve arise from a nucleus in the midbrain, which lies in the gray substance of the floor of the cerebral aqueduct and extends in front of the aqueduct for a short distance into the floor of the third ventricle. From this nucleus the fibers pass forward through the tegmentum, the red nucleus, and the medial part of the substantia nigra, forming a series of curves with a lateral convexity, and emerge from the oculomotor sulcus on the medial side of the cerebral peduncle.Quantitative electroencephalography: Quantitative electroencephalography (QEEG) is a field concerned with the numerical analysis of electroencephalography data and associated behavioral correlates.Gary H. Posner: Gary H. Posner (born c.Temporal analysis of products: Temporal Analysis of Products (TAP), (TAP-2), (TAP-3) is an experimental technique for studyingSpalding Method

(1/168) The adolescent decline of NREM delta, an indicator of brain maturation, is linked to age and sex but not to pubertal stage.

Two dramatic phenomena of human adolescence are sexual maturation and a steep decline in the delta EEG of non-rapid eye movement (NREM) sleep. It has long been speculated that these developmental changes are causally related. Here, we present the first longitudinal data on this issue. Cohorts of 9- and 12-year-old children (n = 31, 38) were studied with in-home sleep EEG recordings at 6-mo intervals over 2 years. Pubertal (Tanner) stage, height, and weight were obtained at each time point. NREM delta power density (DPD) did not change significantly over ages 9-11 years, and its level did not differ in boys and girls. DPD declined by 25% between ages 12 and 14 years. This decline was parallel in the two sexes, but levels were lower in girls, suggesting that their DPD decline began earlier. Mixed effect analyses demonstrated that DPD was strongly related to age with Tanner stage, height, weight and body mass index controlled but that none of these measures of physical and sexual development was related to DPD with age controlled. NREM delta is the sleep EEG component homeostatically related to prior waking duration and the intensity of waking brain activity. We hypothesize that the DPD decline is caused by age-programmed synaptic pruning that decreases waking brain metabolic rate. This reduced rate would decrease the "substrate" for delta homeostasis. Whether or not this interpretation proves correct, these longitudinal data demonstrate that the delta decline in adolescence reflects brain processes that are not predicted by physical growth or sexual maturation.  (+info)

(2/168) The sub-clinical see-saw nystagmus embedded in infantile nystagmus.

A transient, decompensated vertical phoria in an individual with infantile nystagmus syndrome (INS) resulted in two images that oscillated vertically-a diplopic oscillopsia. Ocular motor studies during the vertical oscillopsia recreated by vertical prisms, led to the identification of a sub-clinical see-saw nystagmus (SSN), present under the prism-induced diplopic condition. Retrospective analysis of ocular motor recordings made prior to the above episode of vertical diplopia revealed the presence of that same sub-clinical SSN. The SSN had not been detected previously despite extensive observations and recordings of this subject's pendular IN over a period of forty years. Three- dimensional search-coil data from fourteen additional INS subjects (with pendular and jerk waveforms) confirmed the existence of sub-clinical SSN embedded within the clinically detectable horizontal-torsional IN in seven of the fifteen and a sub-clinical, conjugate, vertical component in the remaining eight. Unlike the clinically visible SSN found in achiasma, the cause of this sub-clinical SSN is hypothesized to be due to a failure of the forces of the oblique muscles (responsible for the torsional component of the IN) to balance out the associated forces of the vertical recti; the net result is a small, sub-clinical SSN. Thus, so-called "horizontal" IN is actually a horizontal-torsional oscillation with a secondary, sub-clinical SSN or conjugate vertical component. The suppression of oscillopsia by efference copy in INS appears to be accomplished for each eye individually, even in a binocular individual. However, failure to fuse the two images results in oscillopsia of one of them.  (+info)

(3/168) Accuracy of the bedside head impulse test in detecting vestibular hypofunction.

OBJECTIVE: To determine the accuracy of the bedside head impulse test (bHIT) by direct comparison with results from the quantitative head impulse test (qHIT) in the same subjects, and to investigate whether bHIT sensitivity and specificity changes with neuro-otological training. METHODS: Video clips of horizontal bHIT to both sides were produced in patients with unilateral and bilateral peripheral vestibular deficits (n = 15) and in healthy subjects (n = 9). For qHIT, eye and head movements were recorded with scleral search coils on the right eye and the forehead. Clinicians (neurologists or otolaryngologists) with at least 6 months of neuro-otological training ("experts": n = 12) or without this training ("non-experts": n = 45) assessed video clips for ocular motor signs of vestibular deficits on either side or of normal vestibular function. RESULTS: On average, bHIT sensitivity was significantly (t test: p<0.05) lower for experts than for non-experts (63% vs 72%), while bHIT specificity was significantly higher for experts than non-experts (78% vs 64%). This outcome was a consequence of the experts' tendency to accept bHIT with corresponding borderline qHIT values as still being normal. Fitted curves revealed that at the lower normal limit of qHIT, 20% of bHIT were rated as deficient by the experts and 37% by the non-experts. CONCLUSIONS: When qHIT is used as a reference, bHIT sensitivity is adequate and therefore clinically useful in the hands of both neuro-otological experts and non-experts. We advise performing quantitative head impulse testing with search coils or high speed video methods when bHIT is not conclusive.  (+info)

(4/168) The role of the ventrolateral frontal cortex in inhibitory oculomotor control.

It has been proposed that the inferior/ventrolateral frontal cortex plays a critical role in the inhibitory control of action during cognitive tasks. However, the contribution of this region to the control of eye movements has not been clearly established. Here, we describe the performance of a group of 23 frontal lobe damaged patients in an oculomotor rule switching task for which the association between a centrally presented visual cue and the direction of a saccade could change from trial to trial. A subset of 16 patients also completed the standard antisaccade task. Ventrolateral damage was found to be a significant predictor of errors in both tasks. Analysis of the rate at which patients corrected errors in the rule switching task also revealed an important dissociation between left and right hemisphere damaged patients. Whilst patients with left ventrolateral damage usually corrected response errors with secondary saccades, those with right hemisphere lesions often failed to do so. The results suggest that the inferior frontal cortex forms part of a wider frontal network mediating inhibitory control over stimulus elicited eye movements. The critical role played by the right ventrolateral region in cognitive tasks may arise due to an additional functional specialization for the monitoring and updating of task rules.  (+info)

(5/168) Torsional deviations with voluntary saccades caused by a unilateral midbrain lesion.

Three dimensional eye rotations were measured using the magnetic search coil technique in a patient with a lesion of the right rostral interstitial nucleus of the medial longitudinal fasciculus (RIMLF) and in four control subjects. Up to 10 degree contralesional torsional deviations with each voluntary saccade were revealed, which also could be seen during bedside examination. There was no spontaneous nystagmus. Based on MRI criteria, the lesion involved the RIMLF but spared the interstitial nucleus of Cajal. To date, this deficit has not been described in patients. Our results support the hypothesis that the vertical-torsional saccade generator in humans is organised similarly as in monkeys: each RIMLF encodes torsional saccades in one direction, while both participate in vertical saccades.  (+info)

(6/168) Evidence for cortical visual substitution of chronic bilateral vestibular failure (an fMRI study).

Bilateral vestibular failure (BVF) is a rare disorder of the labyrinth or the eighth cranial nerve which has various aetiologies. BVF patients suffer from unsteadiness of gait combined with blurred vision due to oscillopsia. Functional MRI (fMRI) in healthy subjects has shown that stimulation of the visual system induces an activation of the visual cortex and ocular motor areas bilaterally as well as simultaneous deactivations of multisensory vestibular cortex areas. Our question was whether the chronic absence of bilateral vestibular input (BVF) causes a plastic cortical reorganization of the above-described visual-vestibular interaction. We used fMRI to measure the differential effects of horizontal visual optokinetic stimulation (OKN) on activations and deactivations in 10 patients with BVF and compared their data directly to those of pairwise age- and sex-matched controls. We found that bilateral activation of the primary visual cortex (inferior and middle occipital gyri, Brodmann area BA 17, 18, 19), the motion-sensitive areas V5 in the middle and inferior temporal gyri (BA 37), and the frontal eye field (BA 8), the right paracentral and superior parietal lobule and the right fusiform and parahippocampal gyri was significantly stronger and the activation clusters were larger than that of the age-matched healthy controls. Small areas of BOLD signal decreases (deactivations), located primarily in the right posterior insula containing the parieto-insular vestibular cortex, were similar to those in the healthy controls. No other sensory brain areas showed unexpected activations or deactivations, e.g. the somatosensory or auditory cortex areas. Our finding of enhanced activations within the visual and ocular motor systems of BVF patients suggests that they might be correlated with an upregulation of visual sensitivity during tracking of visual motion patterns. Functionally, these enhanced activations are independent of optokinetic performance, since the mean slow-phase velocity of OKN in the BVF patients did not differ from that in normals. Although psychophysical and neurophysiological tests have provided various examples of how sensory loss in one modality leads to a substitutional increase of functional sensitivity in other modalities, this study presents the first evidence of visual substitution for vestibular loss by functional imaging.  (+info)

(7/168) The eye movements of dyslexic children during reading and visual search: impact of the visual attention span.

The eye movements of 14 French dyslexic children having a VA span reduction and 14 normal readers were compared in two tasks of visual search and text reading. The dyslexic participants made a higher number of rightward fixations in reading only. They simultaneously processed the same low number of letters in both tasks whereas normal readers processed far more letters in reading. Importantly, the children's VA span abilities related to the number of letters simultaneously processed in reading. The atypical eye movements of some dyslexic readers in reading thus appear to reflect difficulties to increase their VA span according to the task request.  (+info)

(8/168) Task and context determine where you look.


  • fixation
  • when changing its points of fixation, the observer's eye repeatedly returns to the same elements of the picture. (wikipedia.org)
  • If covert attention is common during eye-tracking recordings, the resulting scan-path and fixation patterns would often show not where our attention has been, but only where the eye has been looking, failing to indicate cognitive processing. (wikipedia.org)
  • Play media A saccade (/səˈkɑːd/ sə-KAHD, French for jerk) is a quick, simultaneous movement of both eyes between two or more phases of fixation in the same direction. (wikipedia.org)
  • citation needed] Controlled cortically by the frontal eye fields (FEF), or subcortically by the superior colliculus, saccades serve as a mechanism for fixation, rapid eye movement, and the fast phase of optokinetic nystagmus. (wikipedia.org)
  • Each saccade is a rapid adjustment of the fixation point so that the eye can gather data about a slightly different part of the visual field. (uxmag.com)
  • The click data are interpreted as points of attention (Fixation (visual)) and can be analyzed and visualized analogously to the classical eye tracking. (wikipedia.org)
  • Although the average fixation duration is 200-250 ms (thousandths of a second), the range is from 100 ms to over 500 ms. The distance the eye moves in each saccade (or short rapid movement) is between 1 and 20 characters with the average being 7-9 characters. (wikipedia.org)
  • Listing's
  • Since the VOR can actually rotate the eyes around the line of sight, combined eye and head movements do not always obey Listing's law. (wikipedia.org)
  • In the first set of experiments, conducted by Prof. Clarke's team in cooperation with the Moscow Institute for Biomedical Problems, the Eye Tracking Device was used for the measurement of Listing's plane - a coordinate framework, which is used to define the movement of the eyes in the head. (wikipedia.org)
  • Listing's law, named after German mathematician Johann Benedict Listing (1808-1882), describes the three-dimensional orientation of the eye and its axes of rotation. (wikipedia.org)
  • Listing's law has been shown to hold when the head is stationary and upright and gaze is directed toward far targets, i.e., when the eyes are either fixating, making saccades, or pursuing moving visual targets. (wikipedia.org)
  • Listing's law states that the eye does not achieve all possible 3D orientations and that, instead, all achieved eye orientations can be reached by starting from one specific "primary" reference orientation and then rotating about an axis that lies within the plane orthogonal to the primary orientation's gaze direction (line of sight / visual axis). (wikipedia.org)
  • It can be shown that Listing's law implies that, if we start from any chosen eye orientation, all achieved eye orientations can be reached by starting from this orientation and then rotating about an axis that lies within a specific plane that is associated with this chosen orientation. (wikipedia.org)
  • If one assumes that all achieved eye orientations can be reached from some chosen eye orientation and then rotating about an axis that lies within some specific plane, then the existence of a unique primary orientation with an orthogonal Listing's plane is assured. (wikipedia.org)
  • In this coordinate system, Listing's law simply states that the torsional component of eye orientation is held at zero. (wikipedia.org)
  • Listing's law is the specific realization of the more general 'Donders' law', which states that for any one gaze direction the eye's 3D spatial orientation is unique and independent of how the eye reached that gaze direction (previous gaze directions / eye orientations / temporal movements). (wikipedia.org)
  • Direct measurements show that the location of primary position (and thus the orientation of Listing's plane) varies between subjects. (wikipedia.org)
  • It is often misunderstood that Listing's law says that the eye only rotates about axes in Listing's plane. (wikipedia.org)
  • Listing's plane only provides the orientations of the eye relative to primary position, expressed as an angle of rotation about some axis in Listing's plane (normally using the right-hand rule, where one curls the fingers of the right hand in the direction of rotation and the thumb then points in the direction of the rotation vector). (wikipedia.org)
  • in fact, Listing's law requires that the rotation axis of most saccades lies outside of Listing's plane, more specifically, the rotation axis lies in Listing's plane only if the movement starts or ends at the primary position or if it is a prolongation of such a movement. (wikipedia.org)
  • The axes of rotation associated with Listing's law are only in Listing's plane for movements that head toward or away from primary position. (wikipedia.org)
  • For all other eye movements towards or away from some non-primary position, the eye must rotate about an axis of rotation that tilts out of Listing's plane. (wikipedia.org)
  • fixations
  • In 1879 in Paris, Louis Émile Javal observed that reading does not involve a smooth sweeping of the eyes along the text, as previously assumed, but a series of short stops (called fixations) and quick saccades. (wikipedia.org)
  • This activity is thought to incorporate raw data from successive eye fixations into perceptions of visual cues such as movement, color, texture, and depth. (uxmag.com)
  • In 1979 Kennedy secured funding and a series of papers in collaboration with Wayne S. Murray confirmed that both the duration and location of eye fixations were controlled by linguistic properties of the text being read. (wikipedia.org)
  • He reported that eyes do not move continuously along a line of text, but make short, rapid movements (saccades) intermingled with short stops (fixations). (wikipedia.org)
  • behavior
  • Instead, in this article, we hope to provide some important background knowledge about the neurology behind eye-movement behavior and an explanation of when and how eye tracking can be used as an input to the design process. (uxmag.com)
  • Nevertheless, in clinical routine it is difficult to identify individual levels and training effects of compensatory behavior, since it requires measurement of eye movements in a head unrestrained condition. (jove.com)
  • Studies demonstrated that unrestrained head movements alter the visual exploratory behavior compared to a head-restrained laboratory condition 3 . (jove.com)
  • The data of eye- and head-movement-behavior as well as driving performance are discussed with respect to different oculomotor strategies and in a broader context with respect to possible training effects throughout the testing session and implications on rehabilitation potential. (jove.com)
  • The measurement starts with a small training during which the respondent is gradually introduced and accustomed to the desired click behavior. (wikipedia.org)
  • These basic facts about eye movement have been known for almost a hundred years, but only recently have researchers begun to look at eye movement behavior as a reflection of cognitive processing during reading. (wikipedia.org)
  • however, if the reader gains useful information only from the word directly focused on, then eye movement behavior could shed light on what role the eyes play in reading disorders such as dyslexia. (wikipedia.org)
  • oculomotor
  • Head-fixed saccades can have amplitudes of up to 90° (from one edge of the oculomotor range to the other), but in normal conditions saccades are far smaller, and any shift of gaze larger than about 20° is accompanied by a head movement. (wikipedia.org)
  • Different oculomotor behaviors (frequency and amplitude of eye- and head-movements) are evaluated very quickly during the drive itself by dynamic overlay pictures indicating where the subjects gaze is located on the screen, and by analyzing the data. (jove.com)
  • Technological advances enabled oculomotor measurements to be made both quickly and non-invasively, using micro-devices which have many clinical applications. (wikipedia.org)
  • retinal
  • Electrooculography (EOG/E.O.G.) is a technique for measuring the corneo-retinal standing potential that exists between the front and the back of the human eye. (wikipedia.org)
  • Binocular rivalry is a visual phenomenon wherein one experiences alternating perceptions due to the occurrence of different stimuli presented to the corresponding retinal regions of the two eyes and their competition for perceptual dominance. (wikipedia.org)
  • commercially available
  • In parallel to the space-qualified version of the Eye Tracker a commercially available model has been manufactured by the company Chronos Vision in Berlin and is installed in many laboratories in Europe, North America and Asia, where it represents an essential tool for the examination of numerous neurophysiological phenomena. (wikipedia.org)
  • ocular
  • The high peak velocities and the main sequence relationship can also be used to distinguish micro-/saccades from other eye movements like (ocular tremor, ocular drift and smooth pursuit). (wikipedia.org)
  • Two phases of eye movements associated with blinking can be distinguished: an initial dynamic ocular rotation that occurs with every blink and a subsequent sustained phase 1 that occurs only when closure of the eyelid is prolonged. (arvojournals.org)
  • To investigate the three-dimensional ocular kinematics during the initial phase of blinks, we recorded eye movements in healthy human subjects with dual search coils that were modified to exclude torsional artifacts. (arvojournals.org)
  • For example, miniaturized ocular-videography systems are used to analyze eye movements in freely moving rodents. (wikipedia.org)
  • Note that this is not the same description of ocular torsion as rotation around the line of sight: whereas movements that start or end at the primary position can indeed be performed without any rotation about the line of sight, this is not the case for arbitrary movements. (wikipedia.org)
  • Measuring
  • While also teaching in the psychology department at Stanford University, he designed or co-designed several innovative instruments for measuring properties of the eye, including eyetrackers, auto-refractors, and optical fundus scanners. (wikipedia.org)
  • During this time, Cornsweet continued to invent devices for measuring various properties of the eye and also to teach, first at the Baylor College of Medicine and later at the University of California, Irvine. (wikipedia.org)
  • Play media Eye tracking is the process of measuring either the point of gaze (where one is looking) or the motion of an eye relative to the head. (wikipedia.org)
  • An eye tracker is a device for measuring eye positions and eye movement. (wikipedia.org)
  • By additionally measuring rotation about the torsional axis, the authors investigated whether the three-dimensional rotation of the eye during the early phase of eyelid closure could be assigned to the action of a single extraocular muscle. (arvojournals.org)
  • Video-oculography (VOG) is a non-invasive, video-based method of measuring horizontal, vertical and torsional position components of the movements of both eyes (eye tracking) using a head-mounted mask that is equipped with small cameras. (wikipedia.org)
  • experimental
  • His 1955 Ph.D. dissertation in experimental psychology involved small movements of the eye. (wikipedia.org)
  • The Eye Tracking Device (ETD) is a headmounted device, designed for measurement of three-dimensional eye and head movements under experimental and natural conditions. (wikipedia.org)
  • Spatial coding The psychological community rapidly established a consensus view that when a reader made an incorrect syntactic attachment (or was induced to do so by some experimental manipulation), this led to the deployment of corrective eye movements, involving looking back at the point in the text where the defective attachment had been made. (wikipedia.org)
  • visual
  • Eye trackers are used in research on the visual system, in psychology, in psycholinguistics, marketing, as an input device for human-computer interaction, and in product design. (wikipedia.org)
  • The majority of information input to user experience is visual, and eye tracking provides contextually relevant information that cannot be matched by any other readily available design research method. (uxmag.com)
  • SCT consists of learning to make larger eye movements into the blind field enlarging the visual field of search, which has been proven to be the most useful strategy 1 , not only in natural search tasks but also in mastering daily life activities 2 . (jove.com)
  • However, standard measurements, including routine visual tests and MRI scans, are not sensitive enough for this purpose. (jove.com)
  • Visual acuity is restricted, so the question of how the eyes can be selectively and accurately directed to particular words arises. (wikipedia.org)
  • Eye movement in reading involves the visual processing of written text. (wikipedia.org)
  • VOG techniques have been put to use in a wide field of scientific research related to visual development and cognitive science as well as to pathologies of the eyes and of the visual system. (wikipedia.org)
  • patterns
  • Moreover, prenatal alcohol exposure may have a sexually dimorphic impact on eye movement metrics, with males and females exhibiting differential patterns of deficit. (frontiersin.org)
  • Clinical
  • The MSPT takes advantage of advances in computer technology, information technology, biomechanics, and clinical measurement science. (jove.com)
  • fovea
  • One reason for the saccadic movement of the human eye is that the central part of the retina-known as the fovea-which provides the high-resolution portion of vision is very small in humans, only about 1-2 degrees of vision, but it plays a critical role in resolving objects. (wikipedia.org)
  • The most powerful light receptors are in a central region of the eye called the fovea. (uxmag.com)
  • retina
  • instead, the eyes move around, locating interesting parts of the scene and building up a mental, three-dimensional 'map' corresponding to the scene (as opposed to the graphical map of avians, that often relies upon detection of angular movement on the retina). (wikipedia.org)
  • If the eye moves from center position toward one of the two electrodes, this electrode "sees" the positive side of the retina and the opposite electrode "sees" the negative side of the retina. (wikipedia.org)
  • repeatedly
  • The patient is asked to switch eye position repeatedly between two points (alternating looking from center to the left and from center to the right). (wikipedia.org)
  • cognitive
  • The present article describes how to use eye tracking methodologies to study the cognitive processes involved in text comprehension. (jove.com)
  • muscles
  • Judging from the published figure (Fig. 1 in Ref. 8 ), the inferior rectus muscle showed the most brisk activation of all muscles at the beginning of the eyelid movement. (arvojournals.org)
  • When you look at an object, you're using several muscles to move both eyes to focus on it. (medlineplus.gov)
  • If you have a problem with the muscles, the eyes don't work properly. (medlineplus.gov)
  • hypothesis
  • The hypothesis is often taken for granted by researchers using eye-tracking. (wikipedia.org)
  • During the 1980s, the eye-mind hypothesis was often questioned in light of covert attention, the attention to something that one is not looking at, which people often do. (wikipedia.org)
  • These data support the hypothesis that children with FASD exhibit specific deficits in eye movement control and sensory-motor integration associated with cerebellar and/or brain stem circuits. (frontiersin.org)
  • made
  • In the 1800s, studies of eye movement were made using direct observations. (wikipedia.org)
  • show conclusively that the character of the eye movement is either completely independent of or only very slightly dependent on the material of the picture and how it was made, provided that it is flat or nearly flat. (wikipedia.org)
  • In addition equivalent measurements were made over the initial weeks after the return to Earth of each cosmonaut or astronaut. (wikipedia.org)
  • For example, an eye movement may be made from the word struck back to the word mending. (wikipedia.org)
  • Based on dissection of the human eye he made experiments with water-filled crystal balls. (wikipedia.org)
  • research
  • In the 1950s, Alfred L. Yarbus did important eye tracking research and his 1967 book is often quoted. (wikipedia.org)
  • In the 1970s, eye-tracking research expanded rapidly, particularly reading research. (wikipedia.org)
  • These and other disciplines have had great success leveraging eye tracking as a behavioral research method and to inform the design of communications and interactions. (uxmag.com)
  • Recently, as eye tracking technology has become more affordable and accessible, academics, research suppliers, and eye tracking equipment makers have been experimenting with applying eye tracking to behavioral research in new domains. (uxmag.com)
  • Well-planned and executed eye tracking studies can supplement traditional usability research by providing information about user impressions that the test participant can't report and the researcher can't observe. (uxmag.com)
  • He carries out research into eye movement control in reading and the viewing of static and moving images and is the author of over 100 journal articles. (wikipedia.org)
  • Initially, the principal UK funding agency (the Social Science Research Council) saw no future in work on eye movement control and refused to fund it. (wikipedia.org)
  • From the late 19th to the mid-20th century, investigators used early tracking technologies to assist their observation, in a research climate that emphasised the measurement of human behaviour and skill for educational ends. (wikipedia.org)
  • observation
  • This observation raised important questions about reading, questions which were explored during the 1900s: On which words do the eyes stop? (wikipedia.org)
  • The study of binocular rivalry as a quantum formalism is here based on Neumann's quantum theory of measurement and conscious observation. (wikipedia.org)
  • Javal's observations were characterised by a reliance on naked-eye observation of eye movement in the absence of technology. (wikipedia.org)
  • Despite this, some knowledge appears to have been produced from introspection and naked-eye observation. (wikipedia.org)
  • make
  • citation needed] When scanning immediate surroundings or reading, human eyes make jerky saccadic movements and stop several times, moving very quickly between each stop. (wikipedia.org)
  • In this way, it is possible to make objective and reliable measurements of the effect of each drug, which are unbiased by the investigator or the patient. (clinicaltrials.gov)
  • But the fact remains that many usability practitioners (ourselves included) are using eye tracking as a tool to better understand how people "see" websites and to make more informed design decisions as a result. (uxmag.com)
  • Pointing at stationary targets such as buttons, windows, images, menu items, and controls on computer displays is commonplace and has a well-established modeling tool for analysis - Fitt's law (Fitts, 1954) - which states that the time to make an aimed movement (MT) is a linear function of the index of difficulty of the movement: MT = a + bID. (wikipedia.org)
  • signals
  • This processing architecture is integrated into a ruggedised, IBM compatible PC, which permits visualisation of the eyes and the corresponding signals. (wikipedia.org)
  • Lucid dreaming was subsequently researched by asking dreamers to perform pre-determined physical responses while experiencing a dream, including eye movement signals. (wikipedia.org)
  • mechanisms
  • With respect to mechanisms involving abnormal stapes movement, Dieterich (1989) suggested that a hypermobile stapes with annular ligament damage or subluxation of the stapes may cause abnormal utricular contact. (dizziness-and-balance.com)
  • researchers
  • Additionally, computers allowed researchers to use eye-tracking results in real time, primarily to help disabled users. (wikipedia.org)
  • Eye movement control and reading In 1972, Kennedy spent six months in Paris, coming into contact with members of "Groupe Regard", an informal network of researchers working on psychological issues relating to eye movement control and led by Arianne Levy-Schoen. (wikipedia.org)
  • Sleep researchers also use simplified electrocardiography (EKG) for cardiac activity and actigraphy for motor movements. (wikipedia.org)
  • transient
  • Therefore, we hypothesized that a transient net force along the pulling direction of this muscle could explain why the initial movement of the eyeball is downward and nasalward. (arvojournals.org)
  • observe
  • The word appears to have been coined in the 1880s by French ophthalmologist Émile Javal, who used a mirror on one side of a page to observe eye movement in silent reading, and found that it involves a succession of discontinuous individual movements. (wikipedia.org)
  • rapidly
  • This lack of reliability arises from the fact that eye movement occurs frequently, rapidly, and over small angles, to the extent that it is impossible for an experimenter to perceive and record the data fully and accurately without technological assistance. (wikipedia.org)
  • rapid
  • Although REM stands for "rapid eye movement", this mode of sleep has many other aspects, including virtual paralysis of the body. (wikipedia.org)
  • Sleep is divided into two broad types: non-rapid eye movement (non-REM or NREM sleep) and rapid eye movement (REM sleep). (wikipedia.org)
  • She concluded that lucid dreams were a category of experience quite distinct from ordinary dreams, and predicted that they would turn out to be associated with rapid eye movement sleep (REM sleep). (wikipedia.org)
  • Using Electroencephalography (EEG) and other polysomnographical measurements, LaBerge and others have shown that lucid dreams begin in the Rapid Eye Movement (REM) stage of sleep. (wikipedia.org)
  • The state of the brain, whether it be conscious, in REM sleep, or non-rapid eye movement sleep, changes how sensory information is gated through the thalamus. (wikipedia.org)
  • data
  • For the eye tracking task, a substantial data reduction is performed by the sensor and the front-end processing. (wikipedia.org)
  • several
  • The purpose of this study is to characterize the profile of executive functions and eye movements in several populations of children with developmental disabilities. (clinicaltrials.gov)