Global visual processing for saccadic eye movements

1982 ◽  
Vol 22 (8) ◽  
pp. 1033-1045 ◽  
Author(s):  
John M. Findlay
Keyword(s):  
Eye Movements ◽  
Visual Processing ◽  
Saccadic Eye Movements

scholarly journals The role of action intentionality and effector in the subjective expansion of temporal duration after saccadic eye movements

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
David Melcher ◽  
Devpriya Kumar ◽  
Narayanan Srinivasan
Keyword(s):  
Eye Movements ◽  
Visual Processing ◽  
Saccadic Eye Movements ◽  
Intentional Binding ◽  
Opposite Pattern ◽  
Motor Action ◽  
Saccade Onset ◽  
Backward Shift ◽  
The Moment

Abstract Visual perception is based on periods of stable fixation separated by saccadic eye movements. Although naive perception seems stable (in space) and continuous (in time), laboratory studies have demonstrated that events presented around the time of saccades are misperceived spatially and temporally. Saccadic chronostasis, the “stopped clock illusion”, represents one such temporal distortion in which the movement of the clock hand after the saccade is perceived as lasting longer than usual. Multiple explanations for chronostasis have been proposed including action-backdating, temporal binding of the action towards the moment of its effect (“intentional binding”) and post-saccadic temporal dilation. The current study aimed to resolve this debate by using different types of action (keypress vs saccade) and varying the intentionality of the action. We measured both perceived onset of the motor action and perceived onset of an auditory tone presented at different delays after the keypress/saccade. The results showed intentional binding for the keypress action, with perceived motor onset shifted forwards in time and the time of the tone shifted backwards. Saccades resulted in the opposite pattern, showing temporal expansion rather than compression, especially with cued saccades. The temporal illusion was modulated by intentionality of the movement. Our findings suggest that saccadic chronostasis is not solely dependent on a backward shift in perceived saccade onset, but instead reflects a temporal dilation. This percept of an effectively “longer” period at the beginning of a new fixation may reflect the pattern of suppressed, and then enhanced, visual processing around the time of saccades.

scholarly journals Contrast sensitivity, V1 neural activity, and natural vision

2017 ◽  
Vol 117 (2) ◽  
pp. 492-508 ◽  
Author(s):  
James E. Niemeyer ◽  
Michael A. Paradiso
Keyword(s):  
Eye Movements ◽  
Contrast Sensitivity ◽  
Visual Processing ◽  
Brain Area ◽  
Saccadic Eye Movements ◽  
Visual Sensitivity ◽  
Natural Image ◽  
Spatial Frequencies ◽  
Natural Vision ◽  
Common Laboratory

Contrast sensitivity is fundamental to natural visual processing and an important tool for characterizing both visual function and clinical disorders. We simultaneously measured contrast sensitivity and neural contrast response functions and compared measurements in common laboratory conditions with naturalistic conditions. In typical experiments, a subject holds fixation and a stimulus is flashed on, whereas in natural vision, saccades bring stimuli into view. Motivated by our previous V1 findings, we tested the hypothesis that perceptual contrast sensitivity is lower in natural vision and that this effect is associated with corresponding changes in V1 activity. We found that contrast sensitivity and V1 activity are correlated and that the relationship is similar in laboratory and naturalistic paradigms. However, in the more natural situation, contrast sensitivity is reduced up to 25% compared with that in a standard fixation paradigm, particularly at lower spatial frequencies, and this effect correlates with significant reductions in V1 responses. Our data suggest that these reductions in natural vision result from fast adaptation on one fixation that lowers the response on a subsequent fixation. This is the first demonstration of rapid, natural-image adaptation that carries across saccades, a process that appears to constantly influence visual sensitivity in natural vision. NEW & NOTEWORTHY Visual sensitivity and activity in brain area V1 were studied in a paradigm that included saccadic eye movements and natural visual input. V1 responses and contrast sensitivity were significantly reduced compared with results in common laboratory paradigms. The parallel neural and perceptual effects of eye movements and stimulus complexity appear to be due to a form of rapid adaptation that carries across saccades.

scholarly journals Retinally-generated saccadic suppression of a locust looming-detector neuron: investigations using a robot locust

2004 ◽  
Vol 1 (1) ◽  
pp. 61-77 ◽  
Author(s):  
Roger D. Santer ◽  
Richard Stafford ◽  
F. Claire Rind
Keyword(s):  
Eye Movements ◽  
Visual Processing ◽  
Saccadic Eye Movements ◽  
Initial Response ◽  
Saccadic Suppression ◽  
Real Motion ◽  
Early Visual Processing ◽  
Inhibitory Mechanisms ◽  
Model Response ◽  
Detector Model

A fundamental task performed by many visual systems is to distinguish apparent motion caused by eye movements from real motion occurring within the environment. During saccadic eye movements, this task is achieved by inhibitory signals of central and retinal origin that suppress the output of motion-detecting neurons. To investigate the retinally-generated component of this suppression, we used a computational model of a locust looming-detecting pathway that experiences saccadic suppression. This model received input from the camera of a mobile robot that performed simple saccade-like movements, allowing the model's response to simplified real stimuli to be tested. Retinally-generated saccadic suppression resulted from two inhibitory mechanisms within the looming-detector's input architecture. One mechanism fed inhibition forward through the network, inhibiting the looming-detector's initial response to movement. The second spread inhibition laterally within the network, suppressing the looming-detector's maintained response to movement. These mechanisms prevent a loomingdetector model response to whole-field visual stimuli. In the locust, this mechanism of saccadic suppression may operate in addition to centrally-generated suppression. Because lateral inhibition is a common feature of early visual processing in many organisms, we discuss whether the mechanism of retinally-generated saccadic suppression found in the locust looming-detector model may also operate in these species.

The Preparation of Goal-Directed Movements Requires Selective Visual Attention: Evidence from the Line-Motion Illusion

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 124-124
Author(s):  
H Deubel ◽  
S Shimojo ◽  
I Paprotta
Keyword(s):  
Eye Movements ◽  
Visual Attention ◽  
Visual Processing ◽  
Target Selection ◽  
Saccadic Eye Movements ◽  
Short Soas ◽  
Directed Movement ◽  
Reaching Movement ◽  
Illusory Line Motion ◽  
Motion Effect

Previous research has demonstrated that visual attention is focused on the movement target, both before saccadic eye movements and before manual reaching, allowing for spatially selective object recognition (Deubel and Schneider, 1996 Vision Research36 1827 – 1837; Deubel, Schneider, and Paprotta, 1996 Perception Supplement, 13 – 19). Here we study the illusory line motion effect (Hikosaka et al, 1993 Vision Research33 1219 – 1240) in a dual-task paradigm to further investigate the coupling of attention and movement target selection. Subjects were presented a display with two potential movement targets (small circles). When one of the circles flashed, they performed a reaching movement with the unseen hand to the other stimulus; movements were registered with a Polhemus FastTrack system. At a SOA that was varied between 0 and 1000 ms after the movement cue, a line appeared and connected both stimuli. After the reaching movement, subjects indicated the perceived direction of line motion. In a second experiment, saccadic eye movements instead of reaching movements were studied. The data show that for short SOAs the subjects reported illusory line motion away from the cue location indicating that attention is automatically drawn to the cue. For longer SOAs but well before movement onset the illusory motion effect inverted—evidence for an attention shift to the movement target. The findings were very similar for manual reaching and for saccadic eye movements. The results confirm the hypothesis that the preparation of a goal-directed movement requires the attentional selection of the movement target. We discuss the assumption of a unitary attention mechanism which selects an object for visual processing, and simultaneously provides the information necessary for goal-directed motor action such as saccades, pointing, and grasping.

scholarly journals Comparison of Cortico-Cortical and Cortico-Collicular Signals for the Generation of Saccadic Eye Movements

2002 ◽  
Vol 87 (2) ◽  
pp. 845-858 ◽  
Author(s):  
Stefano Ferraina ◽  
Martin Paré ◽  
Robert H. Wurtz
Keyword(s):  
Cerebral Cortex ◽  
Eye Movements ◽  
Visual Processing ◽  
Full Range ◽  
Saccadic Eye Movements ◽  
Projection Neurons ◽  
Visual Response ◽  
Antidromic Activation ◽  
Cortical Areas ◽  
Saccade Task

Many neurons in the frontal eye field (FEF) and lateral intraparietal (LIP) areas of cerebral cortex are active during the visual-motor events preceding the initiation of saccadic eye movements: they respond to visual targets, increase their activity before saccades, and maintain their activity during intervening delay periods. Previous experiments have shown that the output neurons from both LIP and FEF convey the full range of these activities to the superior colliculus (SC) in the brain stem. These areas of cerebral cortex also have strong interconnections, but what signals they convey remains unknown. To determine what these cortico-cortical signals are, we identified the LIP neurons that project to FEF by antidromic activation, and we studied their activity during a delayed-saccade task. We then compared these cortico-cortical signals to those sent subcortically by also identifying the LIP neurons that project to the intermediate layers of the SC. Of 329 FEF projection neurons and 120 SC projection neurons, none were co-activated by both FEF and SC stimulation. FEF projection neurons were encountered more superficially in LIP than SC projection neurons, which is consistent with the anatomical projection of many cortical layer III neurons to other cortical areas and of layer V neurons to subcortical structures. The estimated conduction velocities of FEF projection neurons (16.7 m/s) were significantly slower that those of SC projection neurons (21.7 m/s), indicating that FEF projection neurons have smaller axons. We identified three main differences in the discharge properties of FEF and SC projection neurons: only 44% of the FEF projection neurons changed their activity during the delayed-saccade task compared with 69% of the SC projection neurons; only 17% of the task-related FEF projection neurons showed saccadic activity, whereas 42% of the SC projection neurons showed such increases; 78% of the FEF projection neurons had a visual response but no saccadic activity, whereas only 55% of the SC projection neurons had similar activity. The FEF and SC projection neurons had three similarities: both had visual, delay, and saccadic activity, both had stronger delay and saccadic activity with visually guided than with memory-guided saccades, and both had broadly tuned responses for disparity stimuli, suggesting that their visual receptive fields have a three-dimensional configuration. These observations indicate that the activity carried between parietal and frontal cortical areas conveys a spectrum of signals but that the preponderance of activity conveyed might be more closely related to earlier visual processing than to the later saccadic stages that are directed to the SC.

scholarly journals Global Saccadic Eye Movements Characterise Artists’ Visual Attention While Drawing

2021 ◽  
pp. 027623742110018
Author(s):  
Suhyun Park ◽  
Louis Wiliams ◽  
Rebecca Chamberlain
Keyword(s):  
Eye Movements ◽  
Visual Processing ◽  
Movement Analysis ◽  
Saccadic Eye Movements ◽  
Future Research ◽  
Eye Movement Analysis ◽  
Free Viewing ◽  
Analysis Technique ◽  
Attentional Shifts ◽  
Representational Drawing

Previous research has shown that artists employ flexible attentional strategies during offline perceptual tasks. The current study explored visual processing online, by tracking the eye movements of artists and non-artists (n=65) while they produced representational drawings of photographic stimuli. The findings revealed that it is possible to differentiate artists from non-artists on the basis of the relative amount of global-to-local saccadic eye movements they make when looking at the target stimulus while drawing, but not in a preparatory free viewing phase. Results indicated that these differences in eye movements are not specifically related to representational drawing ability, and may be a feature of artistic ability more broadly. This eye movement analysis technique may be used in future research to characterise the dynamics of attentional shifts in eye movements while artists are carrying out a range of artistic tasks.

scholarly journals Intrasaccadic perception triggers pupillary constriction

2015 ◽  
Author(s):  
Sebastiaan Mathôt ◽  
Jean-Baptiste Melmi ◽  
Eric Castet
Keyword(s):  
Eye Movements ◽  
Visual Processing ◽  
Peak Velocity ◽  
Visual Awareness ◽  
Saccadic Eye Movements ◽  
Pupillary Response ◽  
Subjective Report ◽  
Vertical Grating ◽  
Pupillary Constriction ◽  
Eye Velocity

It is commonly believed that vision is impaired during saccadic eye movements. However, here we report that some visual stimuli are clearly visible during saccades, and trigger a constriction of the eye's pupil. Participants viewed sinusoid gratings that changed polarity 150 times per second (every 6.67 ms). At this rate of flicker, the gratings were perceived as homogeneous surfaces while participants fixated. However, the flickering gratings contained ambiguous motion: rightward and leftward motion for vertical gratings; upward and downward motion for horizontal gratings. When participants made a saccade perpendicular to the gratings' orientation (e.g., a leftward saccade for a vertical grating), the eye's peak velocity matched the gratings' motion. As a result, the retinal image was approximately stable for a brief moment during the saccade, and this gave rise to an intrasaccadic percept: A normally invisible stimulus became visible when eye velocity was maximal. Our results confirm and extend previous studies by demonstrating intrasaccadic perception using a reflexive measure (pupillometry) that does not rely on subjective report. Our results further show that intrasaccadic perception affects all stages of visual processing, from the pupillary response to visual awareness.

scholarly journals Intrasaccadic perception triggers pupillary constriction

2015 ◽  
Author(s):  
Sebastiaan Mathôt ◽  
Jean-Baptiste Melmi ◽  
Eric Castet
Keyword(s):  
Eye Movements ◽  
Visual Processing ◽  
Peak Velocity ◽  
Visual Awareness ◽  
Saccadic Eye Movements ◽  
Pupillary Response ◽  
Subjective Report ◽  
Vertical Grating ◽  
Pupillary Constriction ◽  
Eye Velocity

It is commonly believed that vision is impaired during saccadic eye movements. However, here we report that some visual stimuli are clearly visible during saccades, and trigger a constriction of the eye's pupil. Participants viewed sinusoid gratings that changed polarity 150 times per second (every 6.67 ms). At this rate of flicker, the gratings were perceived as homogeneous surfaces while participants fixated. However, the flickering gratings contained ambiguous motion: rightward and leftward motion for vertical gratings; upward and downward motion for horizontal gratings. When participants made a saccade perpendicular to the gratings' orientation (e.g., a leftward saccade for a vertical grating), the eye's peak velocity matched the gratings' motion. As a result, the retinal image was approximately stable for a brief moment during the saccade, and this gave rise to an intrasaccadic percept: A normally invisible stimulus became visible when eye velocity was maximal. Our results confirm and extend previous studies by demonstrating intrasaccadic perception using a reflexive measure (pupillometry) that does not rely on subjective report. Our results further show that intrasaccadic perception affects all stages of visual processing, from the pupillary response to visual awareness.

scholarly journals Eye movements shape visual learning

2020 ◽  
Vol 117 (14) ◽  
pp. 8203-8211 ◽  
Author(s):  
Pooya Laamerad ◽  
Daniel Guitton ◽  
Christopher C. Pack
Keyword(s):  
Eye Movements ◽  
Visual Processing ◽  
Visual Learning ◽  
Visual Space ◽  
Saccadic Eye Movements ◽  
Spatial Integration ◽  
Perceptual Stability ◽  
Extensive Training ◽  
Visual Tasks ◽  
Saccade Task

Most people easily learn to recognize new faces and places, and with more extensive practice they can become experts at visual tasks as complex as radiological diagnosis and action video games. Such perceptual plasticity has been thoroughly studied in the context of training paradigms that require constant fixation. In contrast, when observers learn under more natural conditions, they make frequent saccadic eye movements. Here we show that such eye movements can play an important role in visual learning. Observers performed a task in which they executed a saccade while discriminating the motion of a cued visual stimulus. Additional stimuli, presented simultaneously with the cued one, permitted an assessment of the perceptual integration of information across visual space. Consistent with previous results on perisaccadic remapping [M. Szinte, D. Jonikaitis, M. Rolfs, P. Cavanagh, H. Deubel,J. Neurophysiol.116, 1592–1602 (2016)], most observers preferentially integrated information from locations representing the presaccadic and postsaccadic retinal positions of the cue. With extensive training on the saccade task, these observers gradually acquired the ability to perform similar motion integration without making eye movements. Importantly, the newly acquired pattern of spatial integration was determined by the metrics of the saccades made during training. These results suggest that oculomotor influences on visual processing, long thought to subserve the function of perceptual stability, also play a role in visual plasticity.

Sign in / Sign up

Export Citation Format

Share Document