scholarly journals Voluntary Spatial Attention has Different Effects on Voluntary and Reflexive Saccades

2003 ◽  
Vol 3 ◽  
pp. 881-902 ◽  
Author(s):  
Stephanie K. Seidlits ◽  
Tammie Reza ◽  
Kevin A. Briand ◽  
Anne B. Sereno
Keyword(s):  
Eye Movements ◽  
Spatial Attention ◽  
Saccadic Eye Movements ◽  
Fundamental Issue ◽  
Fixation Condition ◽  
The Subject ◽  
Symbolic Cues ◽  
The Relationship ◽  
Reflexive Saccades ◽  
Gap Paradigm

Although numerous studies have investigated the relationship between saccadic eye movements and spatial attention, one fundamental issue remains controversial. Some studies have suggested that spatial attention facilitates saccades, whereas others have claimed that eye movements are actually inhibited when spatial attention is engaged. However, these discrepancies may be because previous research has neglected to separate and specify the effects of attention for two distinct types of saccades, namely reflexive (stimulus-directed) and voluntary (antisaccades). The present study explored the effects of voluntary spatial attention on both voluntary and reflexive saccades. Results indicate that voluntary spatial attention has different effects on the two types of saccades. Antisaccades were always greatly facilitated following the engagement of spatial attention by symbolic cues (arrows) informing the subject where the upcoming saccade should be directed. Reflexive saccades showed little or no cueing effects and exhibited significant facilitation only when these cues were randomly intermixed with uncued trials. In addition, the present study tested the effects of fixation condition (gap, step, and overlap) on attentional modulation. Cueing effects did not vary due to fixation condition. Thus, voluntary spatial attention consistently showed different effects on voluntary and reflexive saccades, and there was no evidence in these studies that voluntary cues inhibit reflexive saccades, even in a gap paradigm.

Short Report: Scrutinization, Spatial Attention, and the Spatial Programming of Saccadic Eye Movements

1992 ◽  
Vol 45 (4) ◽  
pp. 633-647 ◽  
Author(s):  
John M. Findlay ◽  
Zoi Kapoula
Keyword(s):  
Eye Movements ◽  
Visual Attention ◽  
Spatial Attention ◽  
Visual Space ◽  
Saccadic Eye Movements ◽  
Short Report ◽  
Similar Material ◽  
Visual Tasks ◽  
Corrective Saccade ◽  
Spatial Programming

Results are presented from an experiment in which subjects’ eye movements were recorded while they carried out two visual tasks with similar material. One task was chosen to require close visual scrutiny; the second was less visually demanding. The oculomotor behaviour in the two tasks differed in three ways. (1) When scrutinizing, there was a reduction in the area of visual space over which stimulation influences saccadic eye movements. (2) When moving their eyes to targets requiring scrutiny, subjects were more likely to make a corrective saccade. (3) The duration of fixations on targets requiring scrutiny was increased. The results are discussed in relation to current theories of visual attention and the control of saccadic eye movements.

scholarly journals Edit Blindness: The relationship between attention and global change blindness in dynamic scenes.

2008 ◽  
Vol 2 (2) ◽  
Author(s):  
Tim J. Smith ◽  
John M. Henderson
Keyword(s):  
Eye Movements ◽  
Change Blindness ◽  
Saccadic Eye Movements ◽  
Sudden Onset ◽  
Dynamic Scene ◽  
Dynamic Scenes ◽  
Film Editing ◽  
Feature Films ◽  
Scene Viewing ◽  
The Relationship

Although we experience the visual world as a continuous, richly detailed space we often fail to notice large and significant changes. Such change blindness has been demonstrated for local object changes and changes to the visual form of whole images, however it is assumed that total changes from one image to another would be easily detected. Film editing presents such total changes several times a minute yet we rarely seem to be aware of them, a phenomenon we refer to here as edit blindness. This phenomenon has never been empirically demonstrated even though film editors believe they have at their disposal techniques that induce edit blindness, the Continuity Editing Rules. In the present study we tested the relationship between Continuity Editing Rules and edit blindness by instructing participants to detect edits while watching excerpts from feature films. Eye movements were recorded during the task. The results indicate that edits constructed according to the Continuity Editing Rules result in greater edit blindness than edits not adhering to the rules. A quarter of edits joining two viewpoints of the same scene were undetected and this increased to a third when the edit coincided with a sudden onset of motion. Some cuts may be missed due to suppression of the cut transients by coinciding with eyeblinks or saccadic eye movements but the majority seem to be due to inattentional blindness as viewers attend to the depicted narrative. In conclusion, this study presents the first empirical evidence of edit blindness and its relationship to natural attentional behaviour during dynamic scene viewing.

Canceling of Pursuit and Saccadic Eye Movements in Humans and Monkeys

2003 ◽  
Vol 89 (6) ◽  
pp. 2984-2999 ◽  
Author(s):  
Krista Kornylo ◽  
Natalie Dill ◽  
Melissa Saenz ◽  
Richard J. Krauzlis
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Inhibitory Control ◽  
Saccadic Eye Movements ◽  
Preceding Trial ◽  
Stop Signal ◽  
Motor Pathways ◽  
The Subject ◽  
Saccade Preparation ◽  
Countermanding Task

The countermanding paradigm provides a useful tool for examining the mechanisms responsible for canceling eye movements. The key feature of this paradigm is that, on a minority of trials, a stop signal is introduced some time after the appearance of the target, indicating that the subject should cancel the incipient eye movement. If the delay in giving the stop signal is too long, subjects fail to cancel the eye movement to the target stimulus. By modeling this performance as a race between a go process triggered by the appearance of the target and a stop process triggered by the appearance of the stop signal, it is possible to estimate the processing interval associated with canceling the movement. We have now used this paradigm to analyze the canceling of pursuit and saccades. For pursuit, we obtained consistent estimates of the stop process regardless of our technique or assumptions—it took 50–60 ms to cancel pursuit in both humans and monkeys. For saccades, we found different values depending on our assumptions. When we assumed that saccade preparation was under inhibitory control up until movement onset, we found that saccades took longer to cancel (humans: ∼110, monkeys: ∼80 ms) than pursuit. However, when we assumed that saccade preparation includes a final “ballistic” interval not under inhibitory control, we found that the same rapid stop process that accounted for our pursuit results could also account for the canceling of saccades. We favor this second interpretation because canceling pursuit or saccades amounts to maintaining a state of fixation, and it is more parsimonious to assume that this involves a single inhibitory process associated with the fixation system, rather than two separate inhibitory processes depending on which type of eye movement will not be made. From our behavioral data, we estimate that this ballistic interval has a duration of 9–25 ms in monkeys, consistent with the known physiology of the final motor pathways for saccades, although we obtained longer values in humans (28–60 ms). Finally, we examined the effect of trial sequence during the countermanding task and found that pursuit and saccade latencies tended to be longer if the previous trial contained a stop signal than if it did not; these increases occurred regardless of whether the preceding trial was associated with the same or different type of eye movement. Together, these results suggest that a common inhibitory mechanism regulates the initiation of pursuit and 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.

Neuronal death of the cancellation theory?

1994 ◽  
Vol 17 (2) ◽  
pp. 274-275
Author(s):  
Claude Prablanc
Keyword(s):  
Eye Movements ◽  
Clinical Observation ◽  
Saccadic Eye Movements ◽  
Analytic Solutions ◽  
Visual Stability ◽  
Perceptual Stability ◽  
Stable Representation ◽  
The Subject ◽  
The Stability ◽  
The Brain

The question of how the brain can construct a stable representation of the external world despite eye movements is a very old one. If there have been some wrong statements of problems (such as the inverted retinal image), other statements are less naive and have led to analytic solutions possibly adopted by the brain to counteract the spurious effects of eye movements. Following the MacKay (1973) objections to the analytic view of perceptual stability, Bridgeman et al. claim that the idea that signals canceling the effects of saccadic eye movements are needed is also a misconception, as is the claim that stability and position encoding are two distinct problems. It must be remembered, however, that what made the theory of “cancellation” formulated by von Holst and Mittelstaedt (1950) so appealing was the clinical observation of perceptual instability following ocular paralysis. Following the concept of corollary discharge, the theory of efference copy had the advantage of simultaneously solving three problems: the stability of the visual world during the saccade, the same visual stability across saccades, and the visual constancy problem of allowing the subject to know where an object in space is.

scholarly journals Transient spatiotopic integration across saccadic eye movements mediates visual stability

2013 ◽  
Vol 109 (4) ◽  
pp. 1117-1125 ◽  
Author(s):  
Guido M. Cicchini ◽  
Paola Binda ◽  
David C. Burr ◽  
M. Concetta Morrone
Keyword(s):  
Eye Movements ◽  
Human Subjects ◽  
Saccadic Eye Movements ◽  
Spatial Integration ◽  
Interaction Field ◽  
Wide Range ◽  
External Objects ◽  
Induced Motion ◽  
Integration Mechanisms ◽  
The Relationship

Eye movements pose major problems to the visual system, because each new saccade changes the mapping of external objects on the retina. It is known that stimuli briefly presented around the time of saccades are systematically mislocalized, whereas continuously visible objects are perceived as spatially stable even when they undergo large transsaccadic displacements. In this study we investigated the relationship between these two phenomena and measured how human subjects perceive the position of pairs of bars briefly displayed around the time of large horizontal saccades. We show that they interact strongly, with the perisaccadic bar being drawn toward the other, dramatically altering the pattern of perisaccadic mislocalization. The interaction field extends over a wide range (200 ms and 20°) and is oriented along the retinotopic trajectory of the saccade-induced motion, suggesting a mechanism that integrates pre- and postsaccadic stimuli at different retinal locations but similar external positions. We show how transient changes in spatial integration mechanisms, which are consistent with the present psychophysical results and with the properties of “remapping cells” reported in the literature, can create transient craniotopy by merging the distinct retinal images of the pre- and postsaccadic fixations to signal a single stable object.

Microstimulation of the Frontal Eye Field and Its Effects on Covert Spatial Attention

2004 ◽  
Vol 91 (1) ◽  
pp. 152-162 ◽  
Author(s):  
Tirin Moore ◽  
Mazyar Fallah
Keyword(s):  
Eye Movements ◽  
Spatial Attention ◽  
Saccadic Eye Movements ◽  
Visual Signals ◽  
Luminance Change ◽  
Target Event ◽  
Target Luminance ◽  
Electrical Microstimulation ◽  
Increased Sensitivity ◽  
Stimulation Of

Many studies have established that the strength of visual perception and the strength of visual representations within visual cortex vary according to the focus of covert spatial attention. While it is clear that attention can modulate visual signals, the source of this modulation remains unknown. We have examined the possibility that saccade related mechanisms provide a source of spatial attention by studying the effects of electrical microstimulation of the frontal eye fields (FEF) on spatial attention. Monkeys performed a task in which they had to detect luminance changes of a peripheral target while ignoring a flashing distracter. The target luminance change could be preceded by stimulation of the FEF at current levels below that which evoked saccadic eye movements. We found that when the target change was preceded by stimulation of FEF, the monkey could detect smaller changes in target luminance. The increased sensitivity to the target change only occurred when the target was placed in the part of the visual field represented by neurons at the stimulation site. The magnitude of improvement depended on the temporal asynchrony of the stimulation onset and the target event. No significant effect of stimulation was observed when long intervals (>300 ms) between stimulation and the target event were used, and the magnitude of the increased sensitivity decreased systematically with increasing asynchrony. At the shortest asynchrony, FEF stimulation temporally overlapped the target event and the magnitude of the improvement was comparable to that of removing the distracter from the task. These results demonstrate that transient, but potent improvements in the deployment of covert spatial attention can be obtained by microstimulation of FEF sites from which saccadic eye movements are also evoked.

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