Conjugate Eye Movements: Comparison of Cerebral Palsied and Normal Adults,

1995 ◽  
Vol 81 (2) ◽  
pp. 575-591
Author(s):  
Sang K. Lee ◽  
Miriam Legare ◽  
Hao P. Zhang
Keyword(s):  
Cerebral Palsy ◽  
Eye Movements ◽  
Eye Movement ◽  
Correlation Coefficients ◽  
Sine Wave ◽  
Corneal Reflection ◽  
Visuomotor System ◽  
Normal Adults

Stimulus-driven binocular pursuit and saccadic movements (±4°, ±8°; 0.3 Hz, 0.5 Hz) were measured in 6 cerebral palsied adults and 5 normal adults using a head-free corneal reflection technique. Correlation coefficients for binocular position and r2 were calculated; the latter were pooled for each group into 6 categories of eye movement: horizontal and vertical triangle and sine wave pursuit and saccades. The differences between the group means r2 in each category were tested by the Mann-Whitney U. The eye positions were statistically less conjugate for the cerebral palsy group in all categories. The differences and similarities between the groups are discussed with regard to neural and muscular control, visuomotor development, and organization of the visuomotor system.

Brain stem and cortical contributions to the generation of horizontal optokinetic eye movements in humans

1993 ◽  
Vol 10 (2) ◽  
pp. 247-259 ◽  
Author(s):  
Laurence R. Harris ◽  
Terri L. Lewis ◽  
Daphne Maurer
Keyword(s):  
Eye Movements ◽  
Brain Stem ◽  
Eye Movement ◽  
Monocular Viewing ◽  
Coherent Motion ◽  
Slow Phase ◽  
Infrared Reflection ◽  
Sinusoidal Gratings ◽  
Human Adults ◽  
Normal Adults

AbstractWe evaluated the subcortical pathways’ contribution to human adults’ horizontal OKN by using a method similar to that used previously with cats (Harris & Smith, 1990; Smith & Harris, 1991). Five normal adults viewed plaids composed of two drifting sinusoidal gratings arranged such that their individual directions of drift were 60 deg or more from the direction of coherent motion of the overall pattern. Physiological evidence indicates that under monocular viewing, nasalward coherent motion gives advantage to any crossed subcortical contribution while temporalward coherent motion minimizes it. We recorded horizontal eye movement by infrared reflection and asked subjects to report the perceived direction of motion.During both binocular and monocular viewing, the direction of the slow phase of OKN fell closer to the direction of coherent movement than to that of the oriented components. Monocular viewing produced no nasal-temporal asymmetries in the influence of coherent motion on the direction of OKN. This suggests that in humans the influence of coherent motion is mediated primarily by cortical mechanisms and, unlike in cats, with little or no involvement of subcortical mechanisms in the generation of horizontal OKN.

Eye Movements in a Small Sample of Cerebral Palsied Adults

1995 ◽  
Vol 80 (2) ◽  
pp. 355-369 ◽  
Author(s):  
John Coltellaro ◽  
Miriam LeGare ◽  
Joseph Terdiman
Keyword(s):  
Cerebral Palsy ◽  
Eye Movements ◽  
Saccadic Eye Movements ◽  
Sine Wave ◽  
Small Sample ◽  
Square Wave ◽  
Saccadic Velocity ◽  
Saccadic Intrusions ◽  
The Time Domain ◽  
Pursuit Gain

Monocular pursuit and saccadic eye movements were compared between a group of 5 men with cerebral palsy and a group of 5 men with normal movements using an infrared corneal reflection technique. Triangle, sine, and square waves (in the time domain) at 0.3 Hz in the horizontal and vertical dimensions were used as the stimuli for six 10-sec. tests of each subject. The momentary difference between stimulus and eye positions was used to obtain values for five pursuit variables (triangle and sine wave tests) and five saccadic variables (square wave tests). The t tests for differences between these means showed that the cerebral palsy group had more fixations during the four pursuit tests, more saccadic intrusions during the horizontal pursuit tests, a greater maximum pursuit error during the horizontal sine wave test, and a greater maximum fixation error during the horizontal square wave test. The group means were not different for pursuit gain and saccadic velocity and latency. The dynamics of the errors during the tests of pursuit movements indicate that cerebral palsied persons may be unable to maintain the constant velocity of eye movement required to track a triangle wave stimulus. The dynamics of the errors during the tests of saccadic movements indicate that cerebral palsied persons would be unable to use technological devices for assisting communication, which depend on visual fixation as a control signal.

Discharge characteristics of vestibular and saccade neurons in the rostral midbrain of alert cats

1995 ◽  
Vol 73 (6) ◽  
pp. 2129-2143 ◽  
Author(s):  
K. Fukushima ◽  
T. Ohashi ◽  
J. Fukushima ◽  
C. R. Kaneko
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Correlation Coefficients ◽  
Vestibular Stimulation ◽  
Burst Activity ◽  
Interstitial Nucleus Of Cajal ◽  
Discharge Characteristics ◽  
Posterior Canal ◽  
Preferred Direction ◽  
Alert Cats

1. The interstitial nucleus of Cajal (INC) is involved in generation of vertical eye movements. To further explore the neural substrates of INC involvement in eye movements, we examined the discharge characteristics of neurons in the rostral midbrain that discharge for vestibular stimulation and saccades in alert cats. We analyzed 75 vestibular and saccade neurons (VSNs) that showed characteristic discharge during pitch rotation. Of these, 50 exhibited gradually increasing activity during upward slow phases and burst of action potentials during downward fast phases induced by downward pitch. The remaining 25 cells showed the opposite response pattern: gradually increasing activity during downward slow phases and a burst during upward fast phases induced by upward pitch. We classified these cells as downward VSNs and upward VSNs, respectively. The effects of electrical stimulation of the contralateral vestibular nerve were tested for 13 downward VSNs and 2 upward VSNs; all of them were activated at short latencies. 2. All vertical VSNs also showed burst activity associated with spontaneous saccades. The preferred direction for the burst was always the same for saccades and vestibular fast phases. The onset of burst activity preceded the onset of fast eye movement by an average of 35 +/- 14 ms (mean +/- SD). During fast eye movement in other directions, many of these cells also showed an inconsistent burst and the burst often began after the onset of saccades. Half of the upward VSNs examined showed a pause in activity during downward fast eye movement. 3. Burst parameters in the preferred directions were correlated with saccade parameters in half of the vertical VSNs examined, although the correlation coefficients were typically 0.5-0.6. 4. All vertical VSNs had irregular resting activity. Half of the downward VSNs examined showed eye-position sensitivity toward the direction opposite to the preferred direction for the burst activity but only if the period of analysis was restricted to discharge shortly before and after saccades. 5. All downward VSNs examined during sinusoidal rotation in several vertical planes received strong excitatory input from the contralateral anterior canal. Three of four upward VSNs examined received contralateral posterior canal excitation; the exception received ipsilateral posterior canal excitation.(ABSTRACT TRUNCATED AT 400 WORDS)

Eye-Movement and Performance during Reading by Cerebral Palsy Patients

2010 ◽  
pp. 219-233
Author(s):  
Mitsuhiko Karashima
Keyword(s):  
Cerebral Palsy ◽  
Eye Movements ◽  
Eye Movement ◽  
Fixation Duration ◽  
Window Size ◽  
Distribution Map ◽  
Eye Fixation ◽  
Eye Fixations ◽  
And Performance

This chapter introduced the characteristics of CP patients reading Japanese documents in comparison with fully abled students through two experiments. Experiment 1 was designed to study the characteristics in reading Japanese still documents and Experiment 2 was designed to study the characteristics in reading Japanese scrolling documents. The results of Experiment 1 revealed that the CP patients needed more time to read the documents than the students regardless of the difficulty of the documents. The eye fixation duration of the CP patients was generally the same as the students, although slightly longer with the most difficult documents. The frequency of eye fixation of the CP patients was greater than the students regardless of the difficulty. The distribution map of the intervals between the eye fixations revealed that the CP patients performed more eye movements. The results of Experiment 2 revealed that the most comfortable scrolling speed of CP patients was slower than that of the students regardless of the size of the scrolling window. The most comfortable scrolling speed of CP patients was stable regardless of the window size, while the most comfortable scrolling speed of the students increased as the window size increased from 3 to 5 characters and the scrolling speed was stable in 5 characters or more. Further discussions of the occurrence of the characteristics of CP patients reading both the still document and the scrolling document were done.

Age Differences in Eye Movements During Reading: Degenerative Problems or Compensatory Strategy?

2019 ◽  
Vol 24 (4) ◽  
pp. 297-311
Author(s):  
José David Moreno ◽  
José A. León ◽  
Lorena A. M. Arnal ◽  
Juan Botella
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Meta Analysis ◽  
Age Groups ◽  
Behavioral Changes ◽  
Aging Effects ◽  
Movement Data ◽  
Sentence Reading ◽  
The Difference ◽  
Eye Movements During Reading

Abstract. We report the results of a meta-analysis of 22 experiments comparing the eye movement data obtained from young ( Mage = 21 years) and old ( Mage = 73 years) readers. The data included six eye movement measures (mean gaze duration, mean fixation duration, total sentence reading time, mean number of fixations, mean number of regressions, and mean length of progressive saccade eye movements). Estimates were obtained of the typified mean difference, d, between the age groups in all six measures. The results showed positive combined effect size estimates in favor of the young adult group (between 0.54 and 3.66 in all measures), although the difference for the mean number of fixations was not significant. Young adults make in a systematic way, shorter gazes, fewer regressions, and shorter saccadic movements during reading than older adults, and they also read faster. The meta-analysis results confirm statistically the most common patterns observed in previous research; therefore, eye movements seem to be a useful tool to measure behavioral changes due to the aging process. Moreover, these results do not allow us to discard either of the two main hypotheses assessed for explaining the observed aging effects, namely neural degenerative problems and the adoption of compensatory strategies.

scholarly journals Eye Movements in Response to Pain-Related Feelings in the Presence of Low and High Cognitive Loads

2020 ◽  
Vol 10 (5) ◽  
pp. 92
Author(s):  
Ramtin Zargari Marandi ◽  
Camilla Ann Fjelsted ◽  
Iris Hrustanovic ◽  
Rikke Dan Olesen ◽  
Parisa Gazerani
Keyword(s):  
Eye Movements ◽  
Cognitive Load ◽  
Eye Movement ◽  
Cognitive Processing ◽  
Pain Perception ◽  
Cognitive Task ◽  
Load Level ◽  
Task Load ◽  
Pupillary Responses ◽  
Movement Characteristics

The affective dimension of pain contributes to pain perception. Cognitive load may influence pain-related feelings. Eye tracking has proven useful for detecting cognitive load effects objectively by using relevant eye movement characteristics. In this study, we investigated whether eye movement characteristics differ in response to pain-related feelings in the presence of low and high cognitive loads. A set of validated, control, and pain-related sounds were applied to provoke pain-related feelings. Twelve healthy young participants (six females) performed a cognitive task at two load levels, once with the control and once with pain-related sounds in a randomized order. During the tasks, eye movements and task performance were recorded. Afterwards, the participants were asked to fill out questionnaires on their pain perception in response to the applied cognitive loads. Our findings indicate that an increased cognitive load was associated with a decreased saccade peak velocity, saccade frequency, and fixation frequency, as well as an increased fixation duration and pupil dilation range. Among the oculometrics, pain-related feelings were reflected only in the pupillary responses to a low cognitive load. The performance and perceived cognitive load decreased and increased, respectively, with the task load level and were not influenced by the pain-related sounds. Pain-related feelings were lower when performing the task compared with when no task was being performed in an independent group of participants. This might be due to the cognitive engagement during the task. This study demonstrated that cognitive processing could moderate the feelings associated with pain perception.

scholarly journals Role of Primate Cerebellar Hemisphere in Voluntary Eye Movement Control Revealed by Lesion Effects

2009 ◽  
Vol 101 (2) ◽  
pp. 934-947 ◽  
Author(s):  
Masafumi Ohki ◽  
Hiromasa Kitazawa ◽  
Takahito Hiramatsu ◽  
Kimitake Kaga ◽  
Taiko Kitamura ◽  
...  
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Smooth Pursuit ◽  
Movement Control ◽  
Cerebellar Hemisphere ◽  
Target Velocity ◽  
Eye Movement Control ◽  
Pursuit Eye Movements ◽  
Catch Up

The anatomical connection between the frontal eye field and the cerebellar hemispheric lobule VII (H-VII) suggests a potential role of the hemisphere in voluntary eye movement control. To reveal the involvement of the hemisphere in smooth pursuit and saccade control, we made a unilateral lesion around H-VII and examined its effects in three Macaca fuscata that were trained to pursue visually a small target. To the step (3°)-ramp (5–20°/s) target motion, the monkeys usually showed an initial pursuit eye movement at a latency of 80–140 ms and a small catch-up saccade at 140–220 ms that was followed by a postsaccadic pursuit eye movement that roughly matched the ramp target velocity. After unilateral cerebellar hemispheric lesioning, the initial pursuit eye movements were impaired, and the velocities of the postsaccadic pursuit eye movements decreased. The onsets of 5° visually guided saccades to the stationary target were delayed, and their amplitudes showed a tendency of increased trial-to-trial variability but never became hypo- or hypermetric. Similar tendencies were observed in the onsets and amplitudes of catch-up saccades. The adaptation of open-loop smooth pursuit velocity, tested by a step increase in target velocity for a brief period, was impaired. These lesion effects were recognized in all directions, particularly in the ipsiversive direction. A recovery was observed at 4 wk postlesion for some of these lesion effects. These results suggest that the cerebellar hemispheric region around lobule VII is involved in the control of smooth pursuit and saccadic eye movements.

scholarly journals Fixation eye movement abnormalities and stereopsis recovery following strabismus repair

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Talora L. Martin ◽  
Jordan Murray ◽  
Kiran Garg ◽  
Charles Gallagher ◽  
Aasef G. Shaikh ◽  
...  
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Functional Improvement ◽  
Slow Phase ◽  
Fixational Eye Movements ◽  
Movement Characteristics ◽  
Adaptive Mechanisms ◽  
Before And After ◽  
Gaze Holding ◽  
Fixational Saccades

AbstractWe evaluated the effects of strabismus repair on fixational eye movements (FEMs) and stereopsis recovery in patients with fusion maldevelopment nystagmus (FMN) and patients without nystagmus. Twenty-one patients with strabismus, twelve with FMN and nine without nystagmus, were tested before and after strabismus repair. Eye-movements were recorded during a gaze-holding task under monocular viewing conditions. Fast (fixational saccades and quick phases of nystagmus) and slow (inter-saccadic drifts and slow phases of nystagmus) FEMs and bivariate contour ellipse area (BCEA) were analyzed in the viewing and non-viewing eye. Strabismus repair improved the angle of strabismus in subjects with and without FMN, however patients without nystagmus were more likely to have improvement in stereoacuity. The fixational saccade amplitudes and intersaccadic drift velocities in both eyes decreased after strabismus repair in subjects without nystagmus. The slow phase velocities were higher in patients with FMN compared to inter-saccadic drifts in patients without nystagmus. There was no change in the BCEA after surgery in either group. In patients without nystagmus, the improvement of the binocular function (stereopsis), as well as decreased fixational saccade amplitude and intersaccadic drift velocity, could be due, at least partially, to central adaptive mechanisms rendered possible by surgical realignment of the eyes. The absence of improvement in patients with FMN post strabismus repair likely suggests the lack of such adaptive mechanisms in patients with early onset infantile strabismus. Assessment of fixation eye movement characteristics can be a useful tool to predict functional improvement post strabismus repair.

Visual Field Accuracy and Eye Movement Direction: A Child's Eye View

1980 ◽  
Vol 50 (2) ◽  
pp. 631-636
Author(s):  
Evans Mandes
Keyword(s):  
Eye Movements ◽  
Visual Field ◽  
Eye Movement ◽  
Visual Fields ◽  
Movement Direction

Post-exposural eye movements were studied in 32 adults and 24 7-yr.-old children. Stimuli were binary figures exposed tachistoscopically in both visual fields simultaneously. The data showed significant correlations between direction of eye movement and locus of recognition for both children and adults. No significant differences were found in frequencies of eye movements of children and adults. The data are interpreted in terms of the facilitative effects of post-exposural eye movements upon perception for both groups.

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