scholarly journals Intrasaccadic perception triggers pupillary constriction

2015 ◽  
Author(s):  
Sebastiaan Mathôt ◽  
Jean-Baptiste Melmi ◽  
Eric Castet
Keyword(s):  
Eye Movements ◽  
Visual Perception ◽  
Peak Velocity ◽  
Predictive Coding ◽  
Saccadic Eye Movements ◽  
Subjective Report ◽  
Vertical Grating ◽  
Retinal Motion ◽  
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. We suggest that visual perception during saccades is best understood in terms of predictive coding: The retinal motion that occurs during saccades is predictable, offers no evidence for motion in the environment, and is therefore not perceived. But when intrasaccadic visual input violates predictions, a clear intrasaccadic percept arises.

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.

Visual Fatigue and Saccadic Eye Movement Parameters

1983 ◽  
Vol 27 (8) ◽  
pp. 728-732 ◽  
Author(s):  
Ted Megaw ◽  
Tayyar Sen
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Peak Velocity ◽  
Cognitive Task ◽  
Saccadic Eye Movements ◽  
Tracking Task ◽  
Frequency Of Occurrence ◽  
Saccadic Eye Movement ◽  
Visual Fatigue ◽  
Movement Parameters

It has been suggested by Bahill and Stark (1975) that visual fatigue can be identified by changes in some of the saccadic eye movement parameters. These include increases in the frequency of occurrence of glissades and overlapping saccades and reductions in the peak velocity and duration of saccades. In their study, fatigue was induced by the same step tracking task that was used to evaluate the changes in saccadic parameters. However, there is evidence that subjects experience extreme feelings of fatigue while performing such a task and that somehow the task is unnatural. The present study was designed to assess whether there are any differences in the various saccadic parameters obtained while subjects perform a step tracking task and a cognitive task involving the comparison of number strings. Both tasks were presented on a VDU screen. The second objective was to establish whether there are any changes in the parameters for either task as a result of prolonged performance. The results showed no major differences in the saccadic eye movements between the two tasks and no consistent changes resulting from prolonged performance.

scholarly journals Suppression without inhibition: A novel mechanism in the retina accounts for saccadic suppression

2020 ◽  
Author(s):  
Saad Idrees ◽  
Matthias-Philipp Baumann ◽  
Maria M. Korympidou ◽  
Timm Schubert ◽  
Alexandra Kling ◽  
...  
Keyword(s):  
Eye Movements ◽  
Visual Perception ◽  
Receptive Field ◽  
Calcium Imaging ◽  
Ganglion Cells ◽  
Saccadic Eye Movements ◽  
Visual Sensitivity ◽  
Saccadic Suppression ◽  
Retinal Processing ◽  
Retinal Pathways

AbstractVisual perception remains stable across saccadic eye movements, despite the concurrent strongly disruptive visual flow. This stability is partially associated with a reduction in visual sensitivity, known as saccadic suppression, which already starts in the retina with reduced ganglion cell sensitivity. However, the retinal circuit mechanisms giving rise to such suppression remain unknown. Here, we describe these mechanisms using electrophysiology in mouse, pig, and macaque retina, 2-photon calcium imaging, computational modeling, and human psychophysics. We find a novel retinal processing motif underlying retinal saccadic suppression, “dynamic reversal suppression”, which is triggered by sequential stimuli containing contrast reversals. This motif does not involve inhibition but relies on nonlinear transformation of the inherently slow responses of cone photoreceptors by downstream retinal pathways. Two further components of suppression are present in ON ganglion cells and originate in the cells’ receptive field surround, highlighting a novel disparity between ON and OFF ganglion cells. Our results are relevant for any sequential stimulation encountered frequently in naturalistic scenarios.

Properties of Horizontal Saccades Accompanied by Blinks

1998 ◽  
Vol 79 (6) ◽  
pp. 2895-2902 ◽  
Author(s):  
Klaus G. Rottach ◽  
Vallabh E. Das ◽  
Walter Wohlgemuth ◽  
Ari Z. Zivotofsky ◽  
R. John Leigh
Keyword(s):  
Eye Movements ◽  
Peak Velocity ◽  
Dynamic Properties ◽  
Human Subjects ◽  
Saccadic Eye Movements ◽  
Stationary Target ◽  
Normal Human ◽  
The Right ◽  
Straight Ahead ◽  
Omnipause Neurons

Rottach, Klaus G., Vallabh E. Das, Walter Wohlgemuth, Ari Z. Zivotofsky, and R. John Leigh. Properties of horizontal saccades accompanied by blinks. J. Neurophysiol. 79: 2895–2902, 1998. Using the magnetic search coil technique to record eye and lid movements, we investigated the effect of voluntary blinks on horizontal saccades in five normal human subjects. The main goal of the study was to determine whether changes in the dynamics of saccades with blinks could be accounted for by a superposition of the eye movements induced by blinks as subjects fixated a stationary target and saccadic movements made without a blink. First, subjects made voluntary blinks as they fixed on stationary targets located straight ahead or 20° to the right or left. They then made saccades between two continuously visible targets 20 or 40° apart, while either attempting not to blink, or voluntarily blinking, with each saccade. During fixation of a target located straight ahead, blinks induced brief downward and nasalward deflections of eye position. When subjects looked at targets located at right or left 20°, similar initial movements were made by four of the subjects, but the amplitude of the adducted eye was reduced by 65% and was followed by a larger temporalward movement. Blinks caused substantial changes in the dynamic properties of saccades. For 20° saccades made with blinks, peak velocity and peak acceleration were decreased by ∼20% in all subjects compared with saccades made without blinks. Blinks caused the duration of 20° saccades to increase, on average, by 36%. On the other hand, blinks had only small effects on the gain of saccades. Blinks had little influence on the relative velocities of centrifugal versus centripetal saccades, and abducting versus adducting saccades. Three of five subjects showed a significantly increased incidence of dynamic overshoot in saccades accompanied by blinks, especially for 20° movements. Taken with other evidence, this finding suggests that saccadic omnipause neurons are inhibited by blinks, which have longer duration than the saccades that company them. In conclusion, the changes in dynamic properties of saccades brought about by blinks cannot be accounted for simply by a summation of gaze perturbations produced by blinks during fixation and saccadic eye movements made without blinks. Our findings, especially the appearance of dynamic overshoots, suggest that blinks affect the central programming of saccades. These effects of blinks need to be taken into account during studies of the dynamic properties of saccades.

scholarly journals The eye that binds: Feature integration is not disrupted by saccadic eye movements

2019 ◽  
Vol 82 (2) ◽  
pp. 533-549 ◽  
Author(s):  
Josephine Reuther ◽  
Ramakrishna Chakravarthi ◽  
Amelia R. Hunt
Keyword(s):  
Eye Movements ◽  
Spatial Attention ◽  
Saccadic Eye Movements ◽  
Stimulus Presentation ◽  
Feature Integration ◽  
Integration Theory ◽  
Conjunction Errors ◽  
Retinal Motion ◽  
Retinotopic Maps ◽  
Feature Integration Theory

AbstractFeature integration theory proposes that visual features, such as shape and color, can only be combined into a unified object when spatial attention is directed to their location in retinotopic maps. Eye movements cause dramatic changes on our retinae, and are associated with obligatory shifts in spatial attention. In two experiments, we measured the prevalence of conjunction errors (that is, reporting an object as having an attribute that belonged to another object), for brief stimulus presentation before, during, and after a saccade. Planning and executing a saccade did not itself disrupt feature integration. Motion did disrupt feature integration, leading to an increase in conjunction errors. However, retinal motion of an equal extent but caused by saccadic eye movements is spared this disruption, and showed similar rates of conjunction errors as a condition with static stimuli presented to a static eye. The results suggest that extra-retinal signals are able to compensate for the motion caused by saccadic eye movements, thereby preserving the integrity of objects across saccades and preventing their features from mixing or mis-binding.

Impairment of Saccadic Eye Movements by Scopolamine Treatment

1993 ◽  
Vol 76 (1) ◽  
pp. 159-167 ◽  
Author(s):  
Giulia A. Oliva ◽  
Maria P. Bucci ◽  
Roberto Fioravanti
Keyword(s):  
Eye Movements ◽  
Intramuscular Injection ◽  
Peak Velocity ◽  
Saccadic Eye Movements ◽  
Random Time ◽  
Time Interval ◽  
Random Time Interval ◽  
Standard Deviations

The effects of Scopolamine on the dynamics of saccadic eye movements, stimulated over a random time interval, have been investigated in humans. A 0.5-mg dose of the drug (intramuscular injection) had various influences on the basic saccadic parameters. For all subjects duration increased and peak velocity decreased, while for 50% of the subjects saccades became hypometric and latency increased. Standard deviations increased consistently too. Moreover, the Scopolamine treatment affected postsaccadic fixation; at the end of many saccades, the eye drifted considerably, but stability was recovered after a few seconds.

scholarly journals Dissociable effects of subliminal incentives on initiation and velocity control of goal-directed eye movements

2020 ◽  
Author(s):  
Vasko Kilian Hinze ◽  
Ozge Uslu ◽  
Jessica Emily Antono ◽  
Melanie Wilke ◽  
Arezoo Pooresmaeili
Keyword(s):  
Eye Movements ◽  
Peak Velocity ◽  
Saccadic Eye Movements ◽  
Goal Pursuit ◽  
Cognitive Tasks ◽  
Conscious Awareness ◽  
Velocity Control ◽  
Fixed Amount ◽  
Speed Accuracy ◽  
Monetary Gain

AbstractOver the last decades, several studies have demonstrated that conscious and unconscious reward incentives both affect performance in physical and cognitive tasks, suggesting that goal-pursuit can arise from an unconscious will. Whether the planning of goal-directed saccadic eye movements during an effortful task can also be affected by subliminal reward cues has not been systematically investigated. We employed a novel task where participants had to make several eye movements back and forth between a fixation point and a number of peripheral targets. The total number of targets visited by the eyes in a fixed amount of time determined participants’ monetary gain. The magnitude of the reward at stake was briefly shown at the beginning of each trial and was masked by pattern images superimposed in time. We found that when reward cues were fully visible and thus consciously perceived, higher reward enhanced all saccade parameters. However, a dissociation was observed between the effects of subliminal rewards on saccade initiation and peak velocities. While truly subliminal reward cues did increase the number of saccades, they did not enhance saccades’ peak velocity. Additionally, participants who had reached a truly subliminal level of reward perception showed a decrement in accuracy as a function of reward across all visibility levels, as saccade endpoint error was larger when higher reward incentives were expected. This suboptimal speed-accuracy trade-off did not occur in the supraliminal group. These results suggest that although saccades’ initiation can be triggered by subconscious mechanisms, conscious awareness is required to optimally adjust the velocity and accuracy of eye movements based on the expected rewards.

scholarly journals Does pictorial composition guide the eye? Investigating four centuries of last supper pictures

2020 ◽  
Vol 13 (2) ◽  
Author(s):  
Rosa Sancarlo ◽  
Zoya Dare ◽  
Jozsef Arato ◽  
Raphael Rosenberg
Keyword(s):  
Eye Movements ◽  
Visual Perception ◽  
Saccadic Eye Movements ◽  
Individual Level ◽  
Last Supper

Within art literature, there is a centuries-old assumption that the eye follows the lines set out by the composition of a painting. However, recent empirical findings suggest that this may not be true. This study investigates beholders’ saccadic eye movements while looking at fourteen paintings representing the scene of the Last Supper, and their perception of the compositions of those paintings. The experiment included three parts: 1) recording the eye movements of the participants looking at the paintings; 2) asking participants to draw the composition of the paintings; and 3) asking them to rate the amount of depth in the paintings. We developed a novel coefficient of similarity in order to quantify 1) the similarity between the saccades of different observers; 2) the similarity between the compositional drawings of different observers; and 3) the similarity between saccades and compositional drawings. For all of the tested paintings, we found a high, above-chance similarity between the saccades and between the compositional drawings. Additionally, for most of the paintings, we also found a high, above-chance similarity between compositional lines and saccades, both on a collective and on an individual level. Ultimately, our findings suggest that composition does influence visual perception. 

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