Role Of Eye Movements Research Articles

Visual tuning to kinematics of biological motion: the role of eye movements

The visual system is particularly sensitive to the covariation between velocity and curvature that constraint biological motion. Previous work showed that, when this biological constraint is satisfied, simple elliptical motion of a dot looks constant, although its velocity is highly non-uniform. This paper addresses the hypothesis that such a dynamic illusion is dependent upon smooth pursuit eye movements. Subjects had to adjust the kinematics of a dot moving along elliptical trajectories until they perceived a constant velocity. Different pursuit and fixation conditions were tested. The research shows that the dynamic illusion is largely independent of eye movements, suggesting that the visual system has access to implicit knowledge of motor constraints regardless of the concurrent oculomotor commands.

Analysis of information for 3-D motion perception: The role of eye movements

Analysis of information for 3-D motion perception: The role of eye movements

An illusion of velocity in motion perception.

We report a phenomenon that seems to have potential to elucidate a role of eye movement in motion perception. When tracking a target controlled by a triangular wave, the viewer perceives movement of the target like a ball bouncing in between two walls. We measured eye movement with electrooculograms (EOGs) when the subject was tracking a target controlled by a triangular wave. Eye movement after passing the turning point and rapidly returning to the target with saccadic movement and then smoothly tracking the target was recorded for all 4 adults. It was considered that extraretinal information on eye position during saccade may mainly contribute to this illusion.

Reviews: The Role of Eye Movements in Perceptual Processes. Advances in Psychology 88, Vision and Motor Control. Advances in Psychology 85, Effective Colour Displays: Theory and Practice

Reviews: The Role of Eye Movements in Perceptual Processes. Advances in Psychology 88, Vision and Motor Control. Advances in Psychology 85, Effective Colour Displays: Theory and Practice

Eye movements and scene perception.

Research on eye movements and scene perception is reviewed. Following an initial discussion of some basic facts about eye movements and perception, the following topics are discussed: (I) the span of effective vision during scene perception, (2) the role of eye movements in scene perception, (3) integration of information across saccades, (4) scene context, object identification and eye movements, and (5) the control of eye movements. The relationship of eye movements during reading to eye movements during scene perception is considered. A preliminary model of eye movement control in scene perception is described and directions for future research are suggested.

Chapter 15 The pathways and functions of GABA in the oculomotor system

This chapter reviews the anatomical connections involved in vertical and horizontal vestibulo-ocular reflexes, including vertical and horizontal gaze. It also cites experimental evidence to demonstrate the involvement of gamma-aminobutyric acid (GABA) as the major neurotransmitter of inhibitory premotor neurons in the oculomotor system. The chapter compares the monkey and the cat in terms of the distribution and synaptic connections of GABA-labeled neurons and presents a summary of their putative inhibitory role in eye movement. Conjugate eye movement involves coordinating the action of at least one pair of extraocular muscles in each eye. In horizontal eye movement, one muscle (for example, the medial rectus) must be excited and its antagonistic muscle (the lateral rectus) inhibited. In vertical eye movement, this reciprocal relationship includes the superior and inferior recti. GABA is the major inhibitory neurotransmitter utilized by the premotor neurons involved in vertical eye movements. By contrast, glycine is the inhibitory neurotransmitter of most premotor neurons that are related to horizontal eye movements.

Projections of the medial cerebellar nucleus to oculomotor‐related midbrain areas in the rat: An anterograde and retrograde HRP study

The mesencephalic projections of the medial cerebellar nucleus (MCN) were studied in the rat by using the method of anterograde transport of wheat germ agglutinin/horseradish peroxidase to establish connections of the nucleus with oculomotor-related nuclei as a basis for its proposed role in eye movement. The principal targets of projections were the supraoculomotor ventral periaqueductal gray (PAG) and lateral PAG, and paraoculomotor cell groups (nucleus of Darkschewitsch and medial accessory nucleus of Bechterew). Lesser projections were observed to the intermediate layer of the superior colliculus, nucleus of the posterior commissure, and prerubral field. Following transcannular HRP gel implants into the oculomotor complex that included adjacent paraoculomotor nuclei, the largest number of retrogradely labeled cells was found in the caudal MCN. The findings suggest that the caudal MCN in the rat, like the primate fastigial nucleus, is involved in the control of eye movement.

Neuropsychology of Eye Movement

Contents: C. Johnston, Introduction. J. Wirtschafter, A. Weingarden, Neurophysiology and Central Pathways in Oculomotor Control: Saccadic and Pursuit Eye Movements. L. Hainline, Normal Lifespan Developmental Changes in Saccadic and Pursuit Eye Movements. F. Pirozzolo, K. Rayner, Dyslexia: The Role of Eye Movements in Developmental Reading Disabilities. L. Abel, R. Hertle, Effects of Psychoactive Drugs on Ocular Motor Behavior. W. Iacono, Eye Movement Abnormalities in Schizophrenic and Affective Disorders. M. Kuskowski, Eye Movements in Progressive Cerebral Neurological Diseases. E. De Renzi, Oculomotor Disturbances in Hemispheric Disease. W. Hubor, G. L er, U. Lass, Eye Movement Behavior in Aphasia. C. Johnston, Eye Movements in Visual Hemi-Neglect. D. Fisher, The Last Chapter: All About What Has Gone Before.

Collateralization of cerebellar efferent projections to the paraoculomotor region, superior colliculus, and medial pontine reticular formation in the rat: a fluorescent double-labeling study.

Collateralization of cerebellar efferent projections to the oculomotor region, superior colliculus (SC), and medial pontine reticular formation (mPRF) was studied in rats using fluorescent tracer substances. In one group, True Blue (TB) was injected into the oculomotor complex (OMC), including certain paraoculomotor nuclei and supraoculomotor ventral periaqueductal gray (PAG), and Diamidino Yellow (DY) was injected into the medial pontine reticular formation (mPRF) or pontine raphe. The largest number of single-TB-labeled (paraoculomotor-projecting) cells was observed in the medial cerebellar nucleus (MCN) and posterior interposed nucleus (PIN), whereas the largest number of single-DY-labeled (mPRF-projecting) cells was in the MCN. Double-TB/DY-labeled cells were present in the caudal two-thirds of the MCN, suggesting that some MCN neurons send divergent axon collaterals to the paraoculomotor region and mPRF. In another group, TB was injected into the SC and DY into the mPRF. The largest number of single-TB-labeled (SC-projecting) cells was in the PIN, although a considerable number of cells was observed in the caudal MCN, and ventral lateral cerebellar nucleus (LCN). Single-DY-labeled (mPRF-projecting) neurons were primarily located in the central and ventral MCN, but were also present in the lateral anterior interposed (AIN) and in the LCN. Double-TB/DY-labeled neurons were observed in the caudal two-thirds of the MCN and in the central portion of the LCN. The most significant new findings of the study concerned the MCN, which not only contained neurons that projected independently to the paraoculomotor region, SC, and mPRF, but also contained a considerable number of cells which collateralized to project to more than one of these nuclei. The possibility that the MCN projects to the supraoculomotor ventral PAG (containing an oculomotor interneuron system) and to the mPRF, which in the cat and monkey contain neural elements essential to the production of saccadic eye movements, is discussed. The anatomical findings suggest that the MCN in the rat plays an important role in eye movement.

The role of eye movements in motion detection

The roles of small eye movements of fixation, and of different kinds of background in motion detection were studied. Minimum detectable displacement for a luminous line oscillating either in a blank field or in the presence of three types of background was measured under two viewing conditions: normal, when eye movements generate normal movements of the image on the retina, and stabilized when these retinal image movements were nearly eliminated. It was demonstrated that eye movements enhance motion detection for a sinusoidally moving target when the target is superimposed on a patterned background; they are detrimental when there is no background. In addition, it was found that the function relating threshold amplitude to frequency of movement is band-pass when the image is stabilized or when the bar moves on a blank field, and is more low-pass when both the background and the test target are subject to the effects of eye movements.

Role of eye movements in developmental processes of orientation selectivity in the kitten visual cortex

Six-week-old dark-reared kittens were exposed for 6 hr to a normal lighted environment in which they were free to move, but with eyes immobilized. Receptive field properties (orientation selectivity and ocular dominance) of the visual cortical cells (Area 17) were studied. No restoration of orientation selectivity could be observed when only the eyes were immobilized either by oculomotor nerve sections or by extraocular muscles removal, in contrast to what had been observed in intact free moving animals. From these results one can conclude that eye movements must be associated with vision to allow developmental processes of orientation selectivity in the primary cortex. These new results are compared to those obtained previously in paralyzed or restrained animals and those obtained in animals with interruption of orbital afferents.

The Role of Eye Movements in Learning to Read and Reading Disability

The role of eye movements in learning to read and reading disability is reviewed. Characteristics of eye movements during reading for skilled, beginning, and disabled readers are discussed. It is argued that eye movements are not a cause of reading problems and that training children with reading problems to make smooth, efficient eye movements will not increase their reading ability. Rather, eye movement characteristics during reading reflect the difficulty that children have understanding written text.

Improvement in direction discrimination: no role for eye movements.

Practice improves observers’ ability to discriminate between highly similar directions of motion. In an effort to clarify the basis for this improvement, we recorded an observer’s eye movements while he made direction discriminations. We found that the observer did not need to track the moving target in order to learn the discrimination. Both at the beginning and at the end of training the observer’s eye movements more closely resembled movements made while fixating a stationary target, and did not at all resemble movements made while intentionally tracking the stimulus. These results suggest that the learned discrimination of the direction of moving targets is perceptual in nature and does not depend on the learning of a sensorimotor response.

Does Location Cueing Increase the Efficiency of the Early Stages of Perceptual Processing?

Previous research has shown that precueing a stimulus's location in an otherwise empty field leads to more efficient detection of that stimulus. The experiments reported here sought to determine whether or not such cueing affects the early stages(s) of perception. If cueing affects early perceptual processing, then the effect of cueing should be larger the more difficult the perceptual task; otherwise it should not. Experiment 1 failed to find any facilitation due to cueing, but did find significant inhibition from invalid cues. The size of the inhibition did not differ significantly as a function of perceptual difficulty. Experiment 2 employed a less attention-demanding type of cueing and found significant facilitation as well as inhibition. As in the first experiment, the size of the cueing effect did not differ significantly as a function of difficulty. Experiment 3 used a stronger manipulation of difficulty and obtained essentially the same results. However, there was some tendency for the effect of cueing to be larger in the more difficult condition. Experiment 4 tested the possibility that this tendency occurred because the perceptual task was so difficult it required voluntary eye movements. When the possible role of eye movements was minimized, there was no tendency for the effect of cueing to be larger in the difficult than in the easy condition. In Experiment 5 the possibility of eye movements was reduced even further and again, found no significant interaction between cueing and difficulty. It was concluded that cueing does not facilitate early perceptual processing. Rather, cueing affects the efficiency with which stimuli are selected for further processing from an unlimited capacity perceptual system to a limited capacity system.

Hippocampal EEG and motor activity in the cat: The role of eye movements and body acceleration

In cat the relation between various behaviours and the spectral properties of the hippocampal EEG was investigated. Both EEG and behaviour were quantified and results were evaluated statistically. Significant relationships were found between the properties of the hippocampal EEG and motor acts (walking, sitting, eating, stepping and eye movements). These results were compared with those obtained in dog under similar experimental circumstances. Species differences were found particularly regarding the fact that in the cat a dissociation between frequency and amplitude parameters was obtained for some behaviours; this may explain why appreciable differences in the visual interpretation of EEG records of different species are often reported. A simple model of the modulation of hippocampal EEG by brainstem inputs is presented. Particular attention is paid to species differences regarding the anatomy and physiology of the pathways involved in this modulation. It is concluded that in cat a strong relation exists between the modulation of spectral properties of hippocampal EEG and vestibular inputs and/or eye movements. The effects of body acceleration on hippocampal EEG are put in evidence and related to theories of hippocampal function.

Development of the Superior Colliculus

Reference is often made to a study by Adamiik (1872) to illustrate how long we have known that the superior colliculus (SC) plays a role in eye movements. The interest in the involvement of the SC in eye movements has not waned, but has actually increased as a result of recent work describing the activity of SC cells in behaving animals (for comprehensive discussions, see Sparks & Pol­ lack 1977 , Goldberg & Robinson 1978, and Wurtz & Albano 1980). In striking contrast to the decades of exploration of the role the SC plays in eye move­ ments, and in vision in general, is the comparative recency of our appreciation of its multisensory roles. It is even difficult to point to a specific date when this began, because the view of the SC as a structure persisted even after anatomical studies demonstrated that it received nonvisual afferents (e. g. Marburg & Warner 1947, Poirier & Bertrand 1955, Anderson & Berry 1959, Mehler et aI1960). As late as 1962, the deep portion of the SC was described as containing . . . cells that respond to extraoptic stimulation of unknown origin (Altman & Malis 1962). Soon thereafter, however, demonstrations that SC cells could respond to nonvisual stimuli began to accumulate (Bell et aI1964, Jassik-Gerschenfeld 1965, Hom & Hill 1966), and now the involvement of the SC in auditory and somatosensory as well as visual functions is firmly estab­ lished. Many of the early studies that mention the SC do so in passing; seldom was it the major focus of attention. However, an upsurge of interest in the SC took place during the 1960s and has continued unabated since. Of considerable importance in initiating this interest was the description of the profound contralateral sensory neglect that occurred after destruction of the SC in cats

On the retino-cortical mapping

Based on Hubel & Wiesel's physiological findings on the projection from retina to cortex, a schematic model of that stage of visual processing is constructed and its properties investigated. The projection or mapping appears to carry out an automatic “normalization of description” for the same object independent of retinal image size. This property suggests new concepts regarding (1) contrast sensitivity, (2) the nature and role of indirect vision, (3) the role of eye movements and (4) the recognition of patterns and the analysis of scenes.

Role of Eye Movement in the Perception of Moving Images Generated on a Multi CRT Display System

In this paper the authors discuss four experimental results regarding the roles of eye movement on motion perception with special interest to computer generated images which are increasing its importance in man-machine supervision.The first experiment shows how the perception and the eye movement are closely related. The second shows that the perceptions are basically due to the eye movement. Thirdly the effect of eye movement on perception are discussed in relation to presentation methods. Lastly a deformation of the perceived pattern due to the smooth pursuit motion are described. These characteristics should be properly considered in design of moving images by computer.

Vernier discrimination with sequentially-flashed lines: Roles of eye movements, retinal offsets and short-term memory

The two lines of a vertical vernier target were sequentially flashed (2 msec/line; 0.2–800 msec dark interval) while the subject tried to maintain an earlier position of fixation in total darkness. Vernier discrimination deteriorates with increasing dark interval: acuity threshold increases from 29″–26′; constant error generally increases. The errors are a joint result of: (1) displacements between the retinal images of the two lines that are not present in the target; these are produced by involuntary eye movements in the dark interval and (2) deterioration of memory for spatial location signalled by the first line flashed. The entire contribution of involuntary eye movements is due to its effect on retinal offset; extraretinal signals related to involuntary changes in eye position during the dark interval do not influence the discrimination at any dark interval. A systematic influence of eye-movement-produced retinal offset is measured even for the shortest dark interval of 0.2 msec (2.2 msec between centers of flashes). Memory deterioration predominates in determining both constant and variable errors with brief dark intervals; eye-movement-produced retinal offset increases in significance at longer ones. The course of memory deterioration is consistent with a random walk model. At the shortest dark interval acuity was affected by the vertical separation between the two lines of the vernier target; at longer dark intervals this influence was obscured by the eye-movement-produced increases in retinal distance and memory deterioration.

The efferent projections of the pretectal complex: an autoradiographic and horseradish peroxidase analysis

Anterograde autoradiographic data reveal that neurons within the pretectal complex of the tree shrew possess axons which terminate within three general categories of targets. First, there are targets of a major ipsilateral descending pathway which include: the dorsal cap of Kooy of the inferior olivary complex, the dorsolateral and dorsomedial regions of the griseum pontis, the mesencephalic reticular formation which lies immediately dorsal and lateral to the red nucleus, the medial terminal nucleus and the superficial layers of the superior colliculus. A second category of targets receive their pretectal input from a large ascending bundle which projects ipsilaterally to: the reticular and lateral nuclei of the thalamus, the zona incerta, the central lateral and paracentral intralaminar nuclei of the thalamus and bilaterally to the ventral lateral geniculate nucleus. A third category of targets include cranial nerve and closely associated nuclei which play a role in eye movements. Pretectofugal fibers projecting to nuclei in this third category terminate ipsilaterally within the nucleus of Darkschewitsch, bilaterally within the nucleus of the posterior commissure and the interstitial nucleus of Cajal, and contralaterally within the somatic cell column of the oculomotor and trochlear nuclei. There are also commissural projections to contralateral pretectal cell groups. Injections of horseradish peroxidase were placed within 11 pretectal targets. These data, which confirm and extend our autoradiographic findings, show that the majority of pretectal targets receive input from several pretectal nuclei, and that the size of pretectal neurons, rather than the cell groups in which they are located, dictates the termination site(s) of their axons.