Regionalization in the eye of the crabLeptograpsus variegatus: Eye movements evoked by a target moving in different parts of the visual field

1978 ◽  
Vol 123 (4) ◽  
pp. 299-306 ◽  
Author(s):  
David C. Sandeman
Keyword(s):  
Eye Movements ◽  
Visual Field ◽  
Different Parts

Visual asymmetries during face encoding Increased dwell time and fixations in the upper and left hemifields

2018 ◽  
Author(s):  
Fatima Maria Felisberti
Keyword(s):  
Face Recognition ◽  
Eye Movements ◽  
Visual Field ◽  
Face Processing ◽  
Dwell Time ◽  
The Other ◽  
Environmental Cues ◽  
Reading Habits ◽  
The Right

Visual field asymmetries (VFA) in the encoding of groups rather than individual faces has been rarely investigated. Here, eye movements (dwell time (DT) and fixations (Fix)) were recorded during the encoding of three groups of four faces tagged with cheating, cooperative, or neutral behaviours. Faces in each of the three groups were placed in the upper left (UL), upper right (UR), lower left (LL), or lower right (LR) quadrants. Face recognition was equally high in the three groups. In contrast, the proportion of DT and Fix were higher for faces in the left than the right hemifield and in the upper rather than the lower hemifield. The overall time spent looking at the UL was higher than in the other quadrants. The findings are relevant to the understanding of VFA in face processing, especially groups of faces, and might be linked to environmental cues and/or reading habits.

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.

scholarly journals Vision as oculomotor reward: cognitive contributions to the dynamic control of saccadic eye movements

2021 ◽  
Author(s):  
Christian Wolf ◽  
Markus Lappe
Keyword(s):  
Eye Movements ◽  
Visual Field ◽  
Visual System ◽  
Dynamic Control ◽  
Saccadic Eye Movements ◽  
Saccade Target ◽  
Cognitive Mechanisms ◽  
Foveal Vision ◽  
Subsequent Behavior ◽  
High Level

AbstractHumans and other primates are equipped with a foveated visual system. As a consequence, we reorient our fovea to objects and targets in the visual field that are conspicuous or that we consider relevant or worth looking at. These reorientations are achieved by means of saccadic eye movements. Where we saccade to depends on various low-level factors such as a targets’ luminance but also crucially on high-level factors like the expected reward or a targets’ relevance for perception and subsequent behavior. Here, we review recent findings how the control of saccadic eye movements is influenced by higher-level cognitive processes. We first describe the pathways by which cognitive contributions can influence the neural oculomotor circuit. Second, we summarize what saccade parameters reveal about cognitive mechanisms, particularly saccade latencies, saccade kinematics and changes in saccade gain. Finally, we review findings on what renders a saccade target valuable, as reflected in oculomotor behavior. We emphasize that foveal vision of the target after the saccade can constitute an internal reward for the visual system and that this is reflected in oculomotor dynamics that serve to quickly and accurately provide detailed foveal vision of relevant targets in the visual field.

Pursuit and optokinetic deficits following chemical lesions of cortical areas MT and MST

1988 ◽  
Vol 60 (3) ◽  
pp. 940-965 ◽  
Author(s):  
M. R. Dursteler ◽  
R. H. Wurtz
Keyword(s):  
Eye Movements ◽  
Visual Field ◽  
Visual Motion ◽  
Ibotenic Acid ◽  
Motion Processing ◽  
Temporal Area ◽  
Target Speed ◽  
Pursuit Eye Movements ◽  
Medial Superior Temporal ◽  
Visual Motion Processing

1. Previous experiments have shown that punctate chemical lesions within the middle temporal area (MT) of the superior temporal sulcus (STS) produce deficits in the initiation and maintenance of pursuit eye movements (10, 34). The present experiments were designed to test the effect of such chemical lesions in an area within the STS to which MT projects, the medial superior temporal area (MST). 2. We injected ibotenic acid into localized regions of MST, and we observed two deficits in pursuit eye movements, a retinotopic deficit and a directional deficit. 3. The retinotopic deficit in pursuit initiation was characterized by the monkey's inability to match eye speed to target speed or to adjust the amplitude of the saccade made to acquire the target to compensate for target motion. This deficit was related to the initiation of pursuit to targets moving in any direction in the visual field contralateral to the side of the brain with the lesion. This deficit was similar to the deficit we found following damage to extrafoveal MT except that the affected area of the visual field frequently extended throughout the entire contralateral visual field tested. 4. The directional deficit in pursuit maintenance was characterized by a failure to match eye speed to target speed once the fovea had been brought near the moving target. This deficit occurred only when the target was moving toward the side of the lesion, regardless of whether the target began to move in the ipsilateral or contralateral visual field. There was no deficit in the amplitude of saccades made to acquire the target, or in the amplitude of the catch-up saccades made to compensate for the slowed pursuit. The directional deficit is similar to the one we described previously following chemical lesions of the foveal representation in the STS. 5. Retinotopic deficits resulted from any of our injections in MST. Directional deficits resulted from lesions limited to subregions within MST, particularly lesions that invaded the floor of the STS and the posterior bank of the STS just lateral to MT. Extensive damage to the densely myelinated area of the anterior bank or to the posterior parietal area on the dorsal lip of the anterior bank produced minimal directional deficits. 6. We conclude that damage to visual motion processing in MST underlies the retinotopic pursuit deficit just as it does in MT. MST appears to be a sequential step in visual motion processing that occurs before all of the visual motion information is transmitted to the brainstem areas related to pursuit.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Visual field loss, eye movements and visual search

2010 ◽  
Vol 9 (8) ◽  
pp. 1210-1210
Author(s):  
L. McIlreavy ◽  
J. Fiser ◽  
P. Bex
Keyword(s):  
Visual Search ◽  
Eye Movements ◽  
Visual Field ◽  
Visual Field Loss

Optokinetic Memory in the Crab, Carcinus

1966 ◽  
Vol 44 (2) ◽  
pp. 233-245
Author(s):  
G. A. HORRIDGE
Keyword(s):  
Eye Movements ◽  
Visual Field ◽  
Visual Feedback ◽  
Opposite Direction ◽  
Feedback Loop ◽  
Closed Loop ◽  
Dark Period ◽  
Eye Position ◽  
Movement Perception ◽  
Memory Experiment

1. A crab is held at the centre of an illuminated stationary striped drum or any visual field with strong contrasts. After a time all lights are turned off and the drum is moved in the dark. The light is restored when the drum is stationary in its new position. The animal responds by a movement of the eyes. 2. Stimuli of 0.5° over a dark period of 2 min. or 1° over 15 min. give a response. The response depends on the angle of the drum movement, and is slower in performance and less in total amount for longer periods of darkness. 3. On re-illumination the movement of the eye relative to the stationary drum is such that the visual field moves across the eye in the opposite direction to the eye's movement, but nevertheless the perception of small drum oscillations is not impaired. 4. When the visual feedback loop is opened by clamping the seeing eye and painting over the moving one, eye movements can be greater than drum movements, as in movement perception. Comparison of calculated with experimental closed-loop conditions shows that in the memory experiment there is no attenuation or amplification in the visual feedback loop. 5. Perception of very slow movements and stabilization of eye position could, but do not necessarily, depend on this accurate but short-lived directional memory.

scholarly journals Effects of Peripheral Visual Field Loss on Eye Movements During Visual Search

2012 ◽  
Vol 3 ◽  
Author(s):  
Emily Wiecek ◽  
Louis R. Pasquale ◽  
Jozsef Fiser ◽  
Steven Dakin ◽  
Peter J. Bex
Keyword(s):  
Visual Search ◽  
Eye Movements ◽  
Visual Field ◽  
Visual Field Loss ◽  
Peripheral Visual Field

Quick phases control ocular torsion during smooth pursuit

2011 ◽  
Vol 106 (5) ◽  
pp. 2151-2166 ◽  
Author(s):  
Bernhard J. M. Hess ◽  
Jakob S. Thomassen
Keyword(s):  
Eye Movements ◽  
Visual Field ◽  
Rotation Axis ◽  
Three Dimensional ◽  
Oculomotor Control ◽  
Visually Guided ◽  
Open Questions ◽  
Spatial Frequencies ◽  
Eye Rotation ◽  
Smooth Tracking

One of the open questions in oculomotor control of visually guided eye movements is whether it is possible to smoothly track a target along a curvilinear path across the visual field without changing the torsional stance of the eye. We show in an experimental study of three-dimensional eye movements in subhuman primates ( Macaca mulatta) that although the pursuit system is able to smoothly change the orbital orientation of the eye's rotation axis, the smooth ocular motion was interrupted every few hundred milliseconds by a small quick phase with amplitude <1.5° while the animal tracked a target along a circle or ellipse. Specifically, during circular pursuit of targets moving at different angular eccentricities (5°, 10°, and 15°) relative to straight ahead at spatial frequencies of 0.067 and 0.1 Hz, the torsional amplitude of the intervening quick phases was typically around 1° or smaller and changed direction for clockwise vs. counterclockwise tracking. Reverse computations of the eye rotation based on the recorded angular eye velocity showed that the quick phases facilitate the overall control of ocular orientation in the roll plane, thereby minimizing torsional disturbances of the visual field. On the basis of a detailed kinematic analysis, we suggest that quick phases during curvilinear smooth tracking serve to minimize deviations from Donders' law, which are inevitable due to the spherical configuration space of smooth eye movements.

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