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At least 19 recordsLinked to original sources
PubMed1990

The association between fetal body movements, eye movements and heart rate patterns in pregnancies between 25 and 30 weeks of gestation.

Fetal eye movements, fetal body movements and fetal heart rate patterns were studied in healthy fetuses between 25 and 30 weeks of gestation in 21 recordings with a mean recording time of 83.5 min. In contrast with the older fetus, prolonged periods of absence as well as presence of fetal eye or body movements were uncommon. Especially absence of body movements for more than 15 min is extremely rare at this age. These findings emphasize that for the interpretation of fetal biophysical tests, gestational age should be taken into account. A linkage was demonstrated between fetal eye movements and fetal heart rate pattern and between fetal body movements and fetal heart rate pattern, but not between fetal eye movements and fetal body movements. The existence of fetal behavioural states could not be demonstrated.

Eye Movements↗
PubMed1978

Apparent movement, eye movements and phoria when two eyes alternate in viewing a stimulus.

Three experiments were conducted to test the hypothesis that the apparent movement of a stimulus when the two eyes are alternately occluded can be explained by phoria and Hering's principles of visual direction. In experiments 1 and 2, the direction of apparent movement, eye position, and eye movements were measured when eye movements did and did not occur. In experiment 3, the magnitude of apparent movement and the extent of phoria were comapred. Results from the experiments 1 and 2 indicated that the direction of apparent movement could be predicted from the direction of phoria, in conjunction with Hering's principles, and was not contingent on eye movements. In experiment 3, a high positive correlation (r = 0.95) between the magnitude of apparent movement and the extent of phoria was obtained.

Eye Movements↗
PubMed1986

The effects of raising intracranial pressure on breathing movements, eye movements and electrocortical activity in fetal sheep.

Extra-dural or cerebroventricular intracranial pressure was measured in 7 unanaesthetized fetal sheep (123-137 days gestation). Basal intracranial pressure was 6.7 +/- 1.7 mmHg, but there were many transient increases of pressure in association with spontaneous changes of amniotic pressure, fetal intrathoracic pressure, and particularly when the fetal nuchal muscles were active. These spontaneous increases of intracranial pressure were often associated with cessation of breathing movements and change of the electrocorticogram from low to high voltage activity. To test whether increased intracranial pressure influenced breathing movements and electrocortical activity, intracranial pressure was raised either by occluding the superior vena cava for 1 min with an implanted extravascular cuff, or by extra-dural injection of 0.3-1.0 ml of 0.9% NaCl. Increasing the intracranial pressure 5-15 mmHg by either method during low voltage electrocortical activity caused cessation of breathing movements, electro-ocular activity, and change of the electrocorticogram from low to high voltage in a significant proportion of trials. We propose that natural fluctuations of intracranial pressure caused by compression of the fetal body or skull, by body movements or by uterine activity, may cause changes in electrocortical activity and breathing movements.

Animals↗
PubMed1993

Rapid eye movement sleep eye movements in schizophrenia and depression.

OBJECTIVE: To investigate the specificity of rapid eye movement (REM) sleep eye movement measures in schizophrenics, depressives, and nonpsychiatric controls. DESIGN: Survey. SETTING: Inpatient psychiatric hospital. STUDY PARTICIPANTS: Volunteer sample of male veterans who met Research Diagnostic Criteria (RDC) for schizophrenia (n = 21) or major depressive disorder (n = 24), or male veterans recruited from the community with no history of psychiatric illness (n = 13). Patients with a concurrent RDC diagnosis of alcoholism were excluded. After data collection, three schizophrenics, two depressives, and one nonpsychiatric control were eliminated because of two or fewer REM periods on either of the two recording nights. INTERVENTION: None. MAIN OUTCOME MEASURE: Computer-detected total night and within-night measures of REM sleep eye movement density, ie, the ratio of eye movement counts to stage REM minutes. RESULTS: Using a 95% confidence interval, schizophrenics, depressives, and nonpsychiatric controls did not differ in total night or within-night measures of eye movement density. Within nights, eye movement density increased across REM periods in the schizophrenics and nonpsychiatric controls; the depressives showed a flatter within-night distribution associated with their older age. CONCLUSIONS: A broad range of REM sleep eye movement densities characterize both schizophrenics and depressives and substantially overlaps the normal range. Abnormalities of REM sleep eye movement activity should not be considered a biological marker for affective illness.

Adult↗
PubMed1983

Ocular bobbing: abnormal eye movement or eye movement's abnormality?

Ocular bobbing is classified as an abnormal eye movement, resulting from pathological neuronal activity of the brain stem after bilateral pontine lesions. Clinical oculographic study of 5 patients suffering from ocular bobbing shows that upwards voluntary eye movements are abnormal. We suggest that ocular bobbing should not to be regarded as an abnormal eye movement, but, rather, as the only residual movement of patients which are totally deprived of both horizontal and upward movements.

Arterial Occlusive Diseases↗
PubMed2000

[Neurology of eye movements].

Eye movements are necessary for clear and stable vision, for which images of the world should be brought to the fovea and be held steady on the retina. The main types of eye movements consist of saccadic eye movements, vergence, vestibular eye movements, smooth pursuit eye movements and eye movements for visual stabilization. Saccades are fast eye movements and have consistent relationship between their peak velocity and the size of the movements. The burst neurons in the brainstem are the generator of saccades and receive projections from the frontal eye field, supplementary eye field, parietal eye field, basal ganglia, superior colliculus and cerebellum. Saccades are evaluated by a speed and accuracy of the size. There are different types of saccade, such as visually triggered saccades, antisaccades, memory-guided saccade and predictive saccades. The specific test paradigms of saccades may show the localization and the type of diseases. Opsoclonus, flatter-like oscillation, ocular myoclonus, square-wave jerks are characteristic involuntary eye movements. Syndromes of the paramedic pontine reticular formation, medial longitudinal fascicules and one-and-a-half syndrome are caused by disease of the pons.

Brain Stem↗
PubMed1975

Hypnosis and eye movements.

Eye movements (with closed lids) were studied in a group of highly hypnotizable experimental subjects experienced in self-hypnosis, and compared with a random sample of control subjects that had never been hypnotized and were low in waking suggestibility. Approximately half the experimental subjects rolled their eyes upwards to a greater extent when hypnosis was induced than during eye closure while awake. In some subjects eye flutter occurred during hypnosis, but not in the awake condition. During passive hypnosis the mean rates of rapid eye movements were lower, but those of slow eye movements were higher than during the resting awake condition of the same subjects or the random control subjects. The mean rates of horizontal eye movements during suggestions about begin in a train and watching passing telephone poles were higher for the experimental subjects in the hypnosis and 'imagination' sessions than that of the random control group in the imagination session. A proportion of the experimental subjects made more lateral eye movements during hypnosis than during the imagination session, but an equal proportion did not differ between the two conditions. The mean rates and durations of horizontal eye movements during dreaming about a tennis match were greater during hypnosis ('hypnotic' dream), than during the awake condition a few minutes later ('natural' dream), or the awake condition in the imagination session ('imagination' dream) of the same subjects or random controls. The performance and subjective involvement of the experimental subjects during the Barber suggestibility scale, 'nystagmus' suggestions and 'dreaming' did not differ significantly between the two hypnosis sessions, but in most cases were significantly greater during hypnosis than during the imagination session of the same group or the random control group.

Adult↗
PubMed1999

A signal analysis method for impulse-like eye movements.

Eye movement investigations are performed in several fields of medicine. We have developed signal analysis methods of eye movements studied in otoneurology for several years. Previously, we have designed methods for eye movement types of saccades, nystagmus, smooth pursuit, and vestibulo-ocular reflex. In this paper we extend and develop further our method to concern also impulse-like eye movements, i.e. a new type of eye movement tests for investigations of vertiginous patients. According to our preliminary results the use of our method is efficient to differentiate patients with inner ear diseases from normals.

Diagnosis, Computer-Assisted↗
PubMedDate not supplied

A syntactic method for analysis of nystagmus and smooth pursuit eye movement.

Eye movements are studied in neurophysiology, neurology, ophthalmology, and otology both clinically and in research. In this article, a syntactic method for recognition of horizontal nystagmus and smooth pursuit eye movements is presented. Eye movement signals, which are recorded, for example, electro-oculographically, are transformed into symbol strings of context free grammars. These symbol strings are fed to an LR(k) parser, which detects eye movements as sentences of the formal languages produced by these LR(k) grammars. Since LR(k) grammars have been used, the time required by the whole recognition method is directly proportional to the number of symbols in an input string.

Algorithms↗
PubMed1975

Time trends and periodic cycles in REM sleep eye movements.

Eye movements during REM sleep episodes were tabulated in 16 young adults. REM episodes were then broken down into four ranges according to length in min: (1) 11.0-21.3; (2) 21.7-29.7; (3) 30.0-42.3; (4) 42.7 or longer. These data were then analyzed for linear and quadratic trends. Eight episodes had a significant linear trend, 10 had a significant quadratic trend, 7 had both linear and quadratic trends, while 12 had no trend. The residuals from the best-fitting polynomial curve were then subject to a spectral analysis. In addition, 2 long periods of pre-sleep wakefulness (approximately 2 h each) were also analyzed. In general, the spectral analysis revealed the dominant presence of a slow cycle (period of 10 min to about 30 min) the exact period of which varied according to the length of the REM episode. A binomial probability test indicated that the presence of slow cycles was significant in REM episodes except for those in the 21-30 min range. For the episodes of wakefulness, a dominant slow cycle was found in both cases. The results give the impression of similarity in the periodic organization of eye movements during REM sleep and waking. The data also indicated that an ultradian (70-150 min) cycle was present in eye movements during sleep and waking. Further, the finding of a decrease in eye movements before sleep onset, coupled with previous reports of an increase in eye movement after sleep onset, indicate the presence of a circadian cycle.

Adolescent↗
PubMed1985

Adaptive response to ocular muscle weakness in human pursuit and saccadic eye movements.

Eye movement deficits caused by ocular muscle weakness vary according to the position of the eye in the orbit and the direction of eye movement. We studied the ability of both the saccadic and pursuit eye-movement systems to compensate for these anisotropic deficits in four patients with ocular muscle weakness. The eye-position dependence of each patient's motor deficit was characterized by plotting the position of the weak eye against that of the normal eye (in various orbital positions) when fusion was prevented, thus giving a static eye-position curve from which relative muscle strength could be inferred. Movements of the weak eye were smaller and slower than those made by the normal eye, so that the weak eye required more time to acquire a visual target. When patients were forced to view monocularly with their weak eye for several days, both the saccadic and pursuit systems showed changes in the movements of the normal eye consistent with an increased central innervation designed to decrease the time it takes to bring the target's image onto the fovea of the weak eye and to keep it there. These adaptive changes varied with eye position and movement direction and compensated for the weak muscle in both its agonistic and antagonistic actions. Saccadic adaptation consisted of a change in the relationship between saccadic amplitude and retinal error (distance between the target's image and the fovea) to compensate for hypometria (undershoot) and a readjustment of the ratio of the phasic (pulse) and tonic (step) components of the saccadic innervation to suppress postsaccadic ocular drift. Pursuit adaptation consisted of an increase in the relationship between eye acceleration and the rate of motion of the image of the target on the retina during the initial phase of tracking as well as an increase in the velocity during tracking of a target moving at a constant velocity. These changes reflect an increase in pursuit innervation that would cause the weak eye's velocity to approach target velocity sooner. The average acceleration of the normal eye during the initial period of tracking (130 ms) increased by as much as threefold. The corresponding maximum smooth eye velocity increased so that, for example, the pursuit response to a 15 degree/s target movement could be over 50 degree/s in the normal eye.

Adaptation, Physiological↗
PubMed1987

Blink-related eye movements.

Eye movements that accompany a blink have been measured in human subjects by the use of a visual-persistence method. With straight-ahead binocular viewing, each eye typically rotates nasalward and downward 1-2 deg during the closing phase of a blink. These eye movements are more rapid than the lid movements as recorded by high-speed photography. In fact, the eyes have already completed their initial rotation and started back again before the lids are fully closed. With off-center viewing, a blink causes each eye to rotate toward its primary position of regard. Indeed, if the eye is already in that position when the blink starts, the eye moves very little. With eyelids taped open, an eye tracker can be used, and records confirming the visual persistence tracings are obtained. Sequential photography of the cornea in profile reveals that the eye moves inward and back out again during a blink. The amplitude of this retraction is typically less than 1 mm; and its time course, slower than that of the rotational eye movements, parallels the closure and opening of the lids. In normal conditions of viewing there is no evidence of conjugate saccades, or of any large, upward rotation of the eyes (Bell's phenomenon) that was once believed to take place during a blink.

Blinking↗
PubMed1989

Supranuclear disorders of eye movement.

Eye movements are the result of activity in discrete systems. Saccades and smooth pursuit movements respond to target position and target velocity respectively. Compensatory responses to movements that alter the position of the eyes in space depend upon the vestibular and optokinetic systems. Vergence movements allow fusion and binocular vision. Eye movement abnormalities of supranuclear origin may be divided into nystagmus, other ocular oscillations, saccadic dysfunction, smooth pursuit dysfunction, gaze palsy, tonic deviation, and vergence disability. An algorithm for the analysis of supranuclear eye movement disorders is presented.

Convergence, Ocular↗
PubMed2006

Visual field recovery after vision restoration therapy (VRT) is independent of eye movements: an eye tracker study.

AIM: It has been argued that patients with visual field defects compensate for their deficit by making more frequent eye movements toward the hemianopic field and that visual field enlargements found after vision restoration therapy (VRT) may be an artefact of such eye movements. In order to determine if this was correct, we recorded eye movements in hemianopic subjects before and after VRT. METHODS: Visual fields were measured in subjects with homonymous visual field defects (n=15) caused by trauma, cerebral ischemia or haemorrhage (lesion age >6 months). Visual field charts were plotted using both high-resolution perimetry (HRP) and conventional perimetry before and after a 3-month period of VRT, with eye movements being recorded with a 2D-eye tracker. This permitted quantification of eye positions and measurements of deviation from fixation. RESULTS: VRT lead to significant visual field enlargements as indicated by an increase of stimulus detection of 3.8% when tested using HRP and about 2.2% (OD) and 3.5% (OS) fewer misses with conventional perimetry. Eye movements were expressed as the standard deviations (S.D.) of the eye position recordings from fixation. Before VRT, the S.D. was +/-0.82 degrees horizontally and +/-1.16 degrees vertically; after VRT, it was +/-0.68 degrees and +/-1.39 degrees , respectively. A cluster analysis of the horizontal eye movements before VRT showed three types of subjects with (i) small (n=7), (ii) medium (n=7) or (iii) large fixation instability (n=1). Saccades were directed equally to the right or the left side; i.e., with no preference toward the blind hemifield. After VRT, many subjects showed a smaller variability of horizontal eye movements. Before VRT, 81.6% of the recorded eye positions were found within a range of 1 degrees horizontally from fixation, whereas after VRT, 88.3% were within that range. In the 2 degrees range, we found 94.8% before and 98.9% after VRT. Subjects moved their eyes 5 degrees or more 0.3% of the time before VRT versus 0.1% after VRT. Thus, in this study, subjects with homonymous visual field defects who were attempting to fixate a central target while their fields were being plotted, typically showed brief horizontal shifts with no preference toward or away from the blind hemifield. These eye movements were usually less than 1 degrees from fixation. Large saccades toward the blind field after VRT were very rare. CONCLUSION: VRT has no effect on either the direction or the amplitude of horizontal eye movements during visual field testing. These results argue against the theory that the visual field enlargements are artefacts induced by eye movements.

Adult↗
PubMed1992

Influences of hand movements on eye movements in tracking tasks in man.

We investigated horizontal smooth pursuit eye movements and hand movements in tracking tasks in order to find out whether hand movements influence eye movements and if so, in what ways. Externally controlled target movements were tracked either by the eyes alone or by the eyes and right hand together. Because a possible influence might depend on the stimulus, we used two classes of target movements: sinusoidal target movements (predictable target movements) and pseudo-random target movements (unpredictable target movements). Our data show that the eye movements contained only a few small saccades when sinusoidal target movements with frequencies higher than about 1 Hz were tracked by eyes and hand together. More and larger saccades were made when the same target movements were tracked by the eyes alone. The difference in smoothness of eye movements was highly significant between the two tracking conditions. Such a difference was not found during the tracking of a pseudo-random target motion. This suggests that the influence of hand movements is related to the predictability of the stimulus. In contrast to the gain of the smooth pursuit eye movements and the maximum of the cross-correlation function, the gain of the composite eye movements did not depend on the tracking condition. The delay of the eye movements with respect to the (sinusoidal) target movements also showed no dependence on the tracking condition. Visual feedback from the tracking hand was found not to play a role in the difference in eye movements for the two tracking conditions.

Feedback↗
PubMed2005

Scaling of horizontal and vertical fixational eye movements.

Eye movements during fixation of a stationary target prevent the adaptation of the visual system to continuous illumination and inhibit fading of the image. These random, involuntary, small movements are restricted at long time scales so as to keep the target at the center of the field of view. Here we use detrended fluctuation analysis in order to study the properties of fixational eye movements at different time scales. Results show different scaling behavior between horizontal and vertical movements. When the small ballistic movements, i.e., microsaccades, are removed, the scaling exponents in both planes become similar. Our findings suggest that microsaccades enhance the persistence at short time scales mostly in the horizontal component and much less in the vertical component. This difference may be due to the need for continuously moving the eyes in the horizontal plane, in order to match the stereoscopic image for different viewing distances.

Adaptation, Physiological↗
PubMed1977

Reversible perspective figures and eye movements.

Eye movements and perspective reversals were continuously recorded on film for 9 subjects who fixated a central point on black line drawings of the Necker cube and Rubin vase figure. There were significantly more Necker cube reversals than Rubin figure reversals in the 1 1/2-min. test periods. Perceptual reversals were unrelated to the occurrence of eye movements but appear possibly to be related to the perceived tridimensionality of the figures.

Eye Movements↗
PubMed2001

Two auto-detection methods for eye movements during eyes closed.

Eye movements during closed eyes closely reflect changes of the arousal level during transition from wakefulness to sleep. Because they contain both rapid and slow eye movements (REM and SEM), it has been difficult to detect them automatically. Hiroshige recently developed the method of linear regression analysis for automatic detection of the two types of eye movements, and we have developed a template matching method for autodetection. The aim of the present study was to compare both auto-detection methods and visual scoring for REM and SEM. The results revealed high agreement between the two quantitative methods and the visual scoring, indicating that auto-detection of eye movements is useful for quantitative evaluation of arousal level.

Arousal↗