Perception of Visual Space at the Time of Pro- and Anti-Saccades

2004 ◽  
Vol 91 (6) ◽  
pp. 2457-2464 ◽  
Author(s):  
Holger Awater ◽  
Markus Lappe
Keyword(s):  
Eye Movement ◽  
Visual Space ◽  
Saccade Target ◽  
Complete Darkness ◽  
Visual Cue ◽  
Localization Errors ◽  
Mouse Pointer ◽  
Saccade Direction ◽  
Anti Saccades ◽  
Saccadic Localization

The localization of peri-saccadically flashed objects shows two types of errors: first, a uniform shift in saccade direction, and second, a compression of visual space around the saccade target. Whereas the uniform shift occurs when the experiment is performed in complete darkness compression occurs when additional visual references are available. Thus peri-saccadic mislocalization contains motor and visual components. To distinguish between both factors we compared peri-saccadic localization errors during pro- and anti-saccades. In the case of anti-saccades, the visual cue that elicits the saccade and the actual eye movement are in opposite directions. We asked whether peri-saccadic compression can be observed with anti-saccades, and if so, whether the compression is directed toward the visual cue or follows the actual eye movement. In blocked trials, subjects performed saccades either toward a visual cue (pro-saccade) or to the mirrored position opposite to a visual cue (anti-saccade). Peri-saccadically, we flashed a thin vertical bar at one of four possible locations. Subjects had to indicate the perceived position of the bar with a mouse pointer about 500 ms after the saccade. Experiments were performed in complete darkness and with visual references. Peri-saccadic mislocalizations occurred during anti-saccades. The mislocalizations were very similar for pro- and anti-saccades in magnitude and direction. For both, pro- and anti-saccades, mislocalizations were directed toward the actual eye movement and not the visual cue.

Egocentric Action in Early Infancy: Spatial Frames of Reference for Saccades

1997 ◽  
Vol 8 (3) ◽  
pp. 224-230 ◽  
Author(s):  
Rick O. Gilmore ◽  
Mark H. Johnson
Keyword(s):  
Spatial Information ◽  
Visual Space ◽  
Frames Of Reference ◽  
Saccade Target ◽  
Visually Guided ◽  
Retinal Position ◽  
Position Information ◽  
Visual Spatial ◽  
Visually Guided Action ◽  
Spatial Frames Of Reference

The extent to which infants combine visual (i e, retinal position) and nonvisual (eye or head position) spatial information in planning saccades relates to the issue of what spatial frame or frames of reference influence early visually guided action We explored this question by testing infants from 4 to 6 months of age on the double-step saccade paradigm, which has shown that adults combine visual and eye position information into an egocentric (head- or trunk-centered) representation of saccade target locations In contrast, our results imply that infants depend on a simple retinocentric representation at age 4 months, but by 6 months use egocentric representations more often to control saccade planning Shifts in the representation of visual space for this simple sensorimotor behavior may index maturation in cortical circuitry devoted to visual spatial processing in general

Target Selection for Saccadic Eye Movements: Direction-Selective Visual Responses in the Superior Colliculus

2001 ◽  
Vol 86 (5) ◽  
pp. 2527-2542 ◽  
Author(s):  
Gregory D. Horwitz ◽  
William T. Newsome
Keyword(s):  
Superior Colliculus ◽  
Eye Movement ◽  
Discrimination Task ◽  
Visual Motion ◽  
Target Selection ◽  
Small Population ◽  
Saccade Target ◽  
Visual Responses ◽  
Direction Discrimination ◽  
Deep Layers

We investigated the role of the superior colliculus (SC) in saccade target selection in rhesus monkeys who were trained to perform a direction-discrimination task. In this task, the monkey discriminated between opposed directions of visual motion and indicated its judgment by making a saccadic eye movement to one of two visual targets that were spatially aligned with the two possible directions of motion in the display. Thus the neural circuits that implement target selection in this task are likely to receive directionally selective visual inputs and be closely linked to the saccadic system. We therefore studied prelude neurons in the intermediate and deep layers of the SC that can discharge up to several seconds before an impending saccade, indicating a relatively high-level role in saccade planning. We used the direction-discrimination task to identify neurons whose prelude activity “predicted” the impending perceptual report several seconds before the animal actually executed the operant eye movement; these “choice predicting” cells comprised ∼30% of the neurons we encountered in the intermediate and deep layers of the SC. Surprisingly, about half of these prelude cells yielded direction-selective responses to our motion stimulus during a passive fixation task. In general, these neurons responded to motion stimuli in many locations around the visual field including the center of gaze where the visual discriminanda were positioned during the direction-discrimination task. Preferred directions generally pointed toward the location of the movement field of the SC neuron in accordance with the sensorimotor demands of the discrimination task. Control experiments indicate that the directional responses do not simply reflect covertly planned saccades. Our results indicate that a small population of SC prelude neurons exhibits properties appropriate for linking stimulus cues to saccade target selection in the context of a visual discrimination task.

How can selection-for-perception be decoupled from selection-for-action?

2003 ◽  
Vol 26 (4) ◽  
pp. 478-479 ◽  
Author(s):  
Cécile Beauvillain ◽  
Pierre Pouget
Keyword(s):  
Eye Movement ◽  
Movement Control ◽  
Saccade Target ◽  
Eye Movement Control ◽  
Tightly Coupled ◽  
Selection For ◽  
Selection For Action

Evidence is presented for the notion that selection-for-perception and selection-for-action progress in parallel to become tightly coupled at the saccade target before the execution of the movement. Such a conception might be incorporated in the E-Z Reader model of eye-movement control in reading.

scholarly journals Lateralized Frontal Eye Field Activity Precedes Occipital Activity Shortly before Saccades: Evidence for Cortico-cortical Feedback as a Mechanism Underlying Covert Attention Shifts

2010 ◽  
Vol 22 (9) ◽  
pp. 1931-1943 ◽  
Author(s):  
Tjerk P. Gutteling ◽  
Helene M. van Ettinger-Veenstra ◽  
J. Leon Kenemans ◽  
Sebastiaan F. W. Neggers
Keyword(s):  
Visual Cortex ◽  
Discrimination Performance ◽  
Covert Attention ◽  
Saccade Target ◽  
Frontal Eye Field ◽  
Cortical Connections ◽  
Field Activity ◽  
Eye Field ◽  
Frontal Activity ◽  
Saccade Direction

When an eye movement is prepared, attention is shifted toward the saccade end-goal. This coupling of eye movements and spatial attention is thought to be mediated by cortical connections between the FEFs and the visual cortex. Here, we present evidence for the existence of these connections. A visual discrimination task was performed while recording the EEG. Discrimination performance was significantly improved when the discrimination target and the saccade target matched. EEG results show that frontal activity precedes occipital activity contralateral to saccade direction when the saccade is prepared but not yet executed; these effects were absent in fixation conditions. This is consistent with the idea that the FEF exerts a direct modulatory influence on the visual cortex and enhances perception at the saccade end-goal.

scholarly journals Hearing in a world of light: why, where, and how visual and auditory information are connected by the brain

2019 ◽  
Vol 12 (7) ◽  
Author(s):  
Jennifer M. Groh
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Auditory Processing ◽  
Activity Patterns ◽  
Visual Space ◽  
Critical Issue ◽  
Video Stream ◽  
Auditory Information ◽  
Auditory Space ◽  
Keynote Presentation

Keynote by Jenny Groh (Duke University) at the 20th European Conference on Eye Movement Research (ECEM) in Alicante, 19.8.2019 Video stream: https://vimeo.com/356576513 Abstract: Information about eye movements with respect to the head is required for reconciling visual and auditory space. This keynote presentation describes recent findings concerning how eye movements affect early auditory processing via motor processes in the ear (eye movement-related eardrum oscillations, or EMREOs). Computational efforts to understand how eye movements are factored in to auditory processing to produce a reference frame aligned with visual space uncovered a second critical issue: sound location is not mapped but is instead rate (meter) coded in the primate brain, unlike visual space. Meter coding would appear to limit the representation of multiple simultaneous sounds. The second part of this presentation concerns how such a meter code could use fluctuating activity patterns to circumvent this limitation

12. The Role of the Human Prefrontal Cortex in the Response Suppression of Eye Movements

2017 ◽  
Author(s):  
Jason Lloyd Chan
Keyword(s):  
Prefrontal Cortex ◽  
Eye Movement ◽  
Intersection Point ◽  
Response Suppression ◽  
Task Selection ◽  
Ratio Increase ◽  
Time Courses ◽  
Anti Saccades ◽  
Increased Activity

Increased activity in a population of prefrontal cortex neurons has been shown, in previous studies, to precede correct anti‐saccades in primates. In addition, the time courses of two competing processes in these neurons, task selection (which prepares for an eye movement) and saccade suppression (which prepares for the suppression of an eye movement), intersect at a specific time after the presentation of a coloured instruction cue. The purpose of this study is to use eye tracking behaviour to investigate this intersection point and its role in response suppression in regard to the generation of anti‐saccades in humans. Subjects were instructed before a stimulus appears, using a colour cue, to either look towards the stimulus (pro‐saccade) or away from the stimulus (anti‐saccade). Instruction period times varied from 100ms to 1400ms, in 50ms steps. Based on previous primate electrophysiological data, the ratio of direction errors (pro‐saccades on anti‐saccade trials) to correct anti‐saccades was expected to increase around 400ms to 500ms, when the processes of task selection and saccade suppression diverge. A slight ratio increase was found and full results are forthcoming.

Neurons in the monkey superior colliculus predict the visual result of impending saccadic eye movements

1995 ◽  
Vol 73 (5) ◽  
pp. 1988-2003 ◽  
Author(s):  
M. F. Walker ◽  
E. J. Fitzgibbon ◽  
M. E. Goldberg
Keyword(s):  
Receptive Field ◽  
Superior Colliculus ◽  
Eye Movement ◽  
Receptive Fields ◽  
Saccadic Eye Movements ◽  
Superficial Layer ◽  
Saccade Target ◽  
Visual Response ◽  
Intermediate Layers ◽  
Movement Field

1. Previous experiments have shown that visual neurons in the lateral intraparietal area (LIP) respond predictively to stimuli outside their classical receptive fields when an impending saccade will bring those stimuli into their receptive fields. Because LIP projects strongly to the intermediate layers of the superior colliculus, we sought to demonstrate similar predictive responses in the monkey colliculus. 2. We studied the behavior of 90 visually responsive neurons in the superficial and intermediate layers of the superior colliculus of two rhesus monkeys (Macaca mulatta) when visual stimuli or the locations of remembered stimuli were brought into their receptive fields by a saccade. 3. Thirty percent (18/60) of intermediate layer visuomovement cells responded predictively before a saccade outside the movement field of the neuron when that saccade would bring the location of a stimulus into the receptive field. Each of these neurons did not respond to the stimulus unless an eye movement brought it into its receptive field, nor did it discharge in association with the eye movement unless it brought a stimulus into its receptive field. 4. These neurons were located in the deeper parts of the intermediate layers and had relatively larger receptive fields and movement fields than the cells at the top of the intermediate layers. 5. The predictive responses of most of these neurons (16/18, 89%) did not require that the stimulus be relevant to the monkey's rewarded behavior. However, for some neurons the predictive response was enhanced when the stimulus was the target of a subsequent saccade into the neuron's movement field. 6. Most neurons with predictive responses responded with a similar magnitude and latency to a continuous stimulus that remained on after the saccade, and to the same stimulus when it was only flashed for 50 ms coincident with the onset of the saccade target and thus never appeared within the cell's classical receptive field. 7. The visual response of neurons in the intermediate layers of the colliculus is suppressed during the saccade itself. Neurons that showed predictive responses began to discharge before the saccade, were suppressed during the saccade, and usually resumed discharging after the saccade. 8. Three neurons in the intermediate layers responded tonically from stimulus appearance to saccade without a presaccadic burst. These neurons responded predictively to a stimulus that was going to be the target for a second saccade, but not to an irrelevant flashed stimulus. 9. No superficial layer neuron (0/27) responded predictively when a stimulus would not be brought into their receptive fields by a saccade.(ABSTRACT TRUNCATED AT 400 WORDS)

Single neurons in posterior cingulate cortex of behaving macaque: eye movement signals

1996 ◽  
Vol 76 (5) ◽  
pp. 3285-3300 ◽  
Author(s):  
C. R. Olson ◽  
S. Y. Musil ◽  
M. E. Goldberg
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Neuronal Activity ◽  
Cingulate Cortex ◽  
Posterior Cingulate Cortex ◽  
Amplitude Dependence ◽  
Saccade Amplitude ◽  
Posterior Cingulate ◽  
Level Of Activity ◽  
Saccade Direction

1. Posterior cingulate cortex, although widely regarded as a part of the limbic system, is connected most strongly to parietal and frontal areas with sensory, motor, and cognitive functions. To gain insight into the functional nature of posterior cingulate cortex, we have recorded from its neurons in monkeys performing oculomotor tasks known to activate parietal and frontal neurons. We have found that posterior cingulate neurons fire during periods of ocular fixation at a rate determined by the angle of gaze and by the size and direction of the preceding eye movement. 2. The activity of 530 posterior cingulate neurons was monitored while rhesus macaque monkeys made visually guided eye movements to spots projected on a tangent screen. 3. In 150/530 neurons, a statistically significant shift in the rate of discharge occurred around the time of onset of saccadic eye movements. The preponderant form of response was an increase in activity (142/150 neurons). 4. In 142 neurons exhibiting significant excitation after saccades in at least one direction, the level of discharge was analyzed as a function of time relative to onset of the saccade. Across the neuronal population as a whole, activity increased sharply at the moment of onset of the saccade, rising to a maximum after 200 ms and then declining slowly. The net level of discharge remained well above presaccadic baseline even after > 1 s of postsaccadic fixation. 5. In 63 neurons, the postsaccadic rate of discharge was analyzed relative to the angle of the eye in the orbit by monitoring neuronal activity while the monkey executed saccades of uniform direction and amplitude to four targets spaced at 16-deg intervals along a line. The postsaccadic firing level was significantly dependent on orbital angle in 44/63 neurons. 6. In 45 neurons, the postsaccadic rate of discharge was analyzed relative to saccade direction by monitoring neuronal activity while the monkey executed 16-deg saccades to a constant target from diametrically opposed starting points. The postsaccadic level of activity was significantly dependent on saccade direction in 20/ 45 neurons. 7. In 58 neurons, the postsaccadic rate of discharge was analyzed relative to saccade amplitude by monitoring neuronal activity while the monkey executed saccades, which varied in amplitude (4, 8, 16, and 32 deg) but which were constant in direction and brought the eye to bear on a constant endpoint. The postsaccadic level of activity was significantly dependent on saccade amplitude in 24/58 neurons. In all neurons exhibiting significant amplitude-dependence, stronger firing accompanied larger saccades. 8. The activity of 10 neurons was monitored during smooth pursuit eye movements (20 deg/s upward, downward, leftward, and rightward). The level of firing varied as a function of both the position of the eye (9 neurons) and the velocity of the eye (6 neurons). 9. We conclude that posterior cingulate neurons monitor eye movements and eye position. It is unlikely that they participate in the generation of eye movements because their shifts of discharge follow the onset of the movements. Eye-movement-related signals in posterior cingulate cortex may reflect the participation of this area in assigning spatial coordinates to retinal images.

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