Higher level influences on saccade generation in normals and patients with visual hemineglect

1999 ◽  
Vol 22 (4) ◽  
pp. 688-689
Author(s):  
Wolfgang Heide ◽  
Andreas Sprenger ◽  
Detlef Kömpf
Keyword(s):  
Human Subjects ◽  
Perceptual Processing ◽  
Visual Exploration ◽  
Frontal Eye Field ◽  
Automatic Processes ◽  
Eye Field ◽  
Level 3 ◽  
Normal Human ◽  
Reflexive Saccades ◽  
Saccade Generation

In this commentary we describe findings in normal human subjects and in patients with visual hemineglect that support the importance of higher-level influences on saccade generation during visual exploration. As the duration of fixations increases with increases in the cognitive demand of the task, the timing of exploratory saccades is controlled more by centers of cognitive and perceptual processing at levels 4 and 5 than by reflex-like automatic processes at level 3. In line with this, unilateral frontal eye field lesions impair systematic, intentional saccadic exploration of visual scenes, causing prolonged fixations and contralesional hemineglect, but leave visually triggered reflexive saccades largely intact.

Predictive human pursuit and "orbital goal" of microstimulated smooth eye movements

1995 ◽  
Vol 74 (3) ◽  
pp. 1358-1361 ◽  
Author(s):  
P. van Gelder ◽  
S. Lebedev ◽  
W. H. Tsui
Keyword(s):  
Smooth Pursuit ◽  
Human Subjects ◽  
Initial Position ◽  
Common Point ◽  
Frontal Eye Field ◽  
Moving Target ◽  
The Gaze ◽  
Target Trajectory ◽  
Eye Field ◽  
Normal Human

1. Anticipatory saccades in smooth pursuit move the point of gaze from near the moving target to well ahead of it, interrupting accurate smooth pursuit. Their effects on the pursuit process were studied in 22 normal human subjects. We presented horizontal periodic target trajectories of 30 degrees amplitude and 30 degrees/s constant velocity or 0.4 Hz sinusoidal velocity in 40-s trials. Saccades and surrounding smooth eye movement (SEM) segments were marked and classified by computer. 2. Anticipatory saccades were often followed by slowed SEM that tended to intercept the target at the endpoint of its trajectory. This was seen in the distribution of projections of the initial 60 ms of postsaccadic SEM to the time of the trajectory endpoint. Magnitude of this SEM tended to follow a function of the time and location of the endpoint of the anticipatory saccade, decreasing as the anticipatory saccades landed closer to the trajectory endpoint. 3. The time and location of the target trajectory endpoint seemed to be the goal for this SEM. We believe this to demonstrate the predictive use of the period and amplitude of the trajectory in smooth pursuit, apart from the instantaneous velocity match of the target. 4. Gottlieb and coworkers in the frontal eye field and Ron and Robinson in the cerebellum produced SEMs in the monkey by microstimulation. At some sites in both structures, direction and velocity of the SEMs depended on the initial position of the eye in that the elicited SEMs appeared to be converging toward a common point, or "orbital goal", and the SEM velocity diminished as the gaze neared that goal.2+ Both our SEM after anticipatory saccades and microstimulated SEM in the monkey slowed as the initial position was brought closer to the inferred orbital goal. This similarity suggests that the goal-directed SEM sites in the monkey might be part of a mechanism for predictive pursuit.

Frontal eye field: A cortical salience map

1999 ◽  
Vol 22 (4) ◽  
pp. 699-700 ◽  
Author(s):  
Kirk G. Thompson ◽  
Narcisse P. Bichot
Keyword(s):  
Visual Attention ◽  
Frontal Eye Field ◽  
Frontal Eye Fields ◽  
Eye Field ◽  
Salience Map ◽  
Saccade Generation

The concept of a salience map has become important for the development of theories of visual attention and saccade generation. Recent studies have shown that the frontal eye fields have all of the characteristics of a salience map.

Repetition Suppression Dissociates Spatial Frames of Reference in Human Saccade Generation

2010 ◽  
Vol 104 (3) ◽  
pp. 1239-1248 ◽  
Author(s):  
Stan Van Pelt ◽  
Ivan Toni ◽  
Jörn Diedrichsen ◽  
W. Pieter Medendorp
Keyword(s):  
Reference Frames ◽  
Target Location ◽  
Blood Oxygenation ◽  
Frontal Eye Field ◽  
Supplementary Eye Field ◽  
Repetition Suppression ◽  
Spatial Frames Of Reference ◽  
Oxygenation Level ◽  
Eye Field ◽  
Saccade Generation

The path from perception to action involves the transfer of information across various reference frames. Here we applied a functional magnetic resonance imaging (fMRI) repetition suppression paradigm to determine the reference frame(s) in which the cortical activity is coded at several phases of the sensorimotor transformation for a saccade, including sensory processing, saccade planning, and saccade execution. We distinguished between retinal (eye-centered) and nonretinal (e.g., head-centered) coding frames in three key regions: the intraparietal sulcus (IPS), frontal eye field (FEF), and supplementary eye field (SEF). Subjects ( n = 18) made delayed saccades to one of five possible peripheral targets, separated at intervals of 9° visual angle. Target locations were chosen pseudorandomly, based on a 2 × 2 factorial design, with factors retinal and nonretinal coordinates and levels novel and repeated. In all three regions, analysis of the blood oxygenation level dependent dynamics revealed an attenuation of the fMRI signal in trials repeating the location of the target in retinal coordinates. The amount of retinal suppression varied across the three phases of the trial, with the strongest suppression during saccade planning. The paradigm revealed only weak traces of nonretinal coding in these regions. Further analyses showed an orderly representation of the retinal target location, as expressed by a contralateral bias of activation, in the IPS and FEF, but not in the SEF. These results provide evidence that the sensorimotor processing in these centers reflects saccade generation in eye-centered coordinates, irrespective of their topographic organization.

Interaction of the Frontal Eye Field and Superior Colliculus for Saccade Generation

2001 ◽  
Vol 85 (2) ◽  
pp. 804-815 ◽  
Author(s):  
Doug P. Hanes ◽  
Robert H. Wurtz
Keyword(s):  
Superior Colliculus ◽  
Brain Stem ◽  
Neural Plasticity ◽  
Recovery Of Function ◽  
Frontal Eye Field ◽  
Indirect Pathway ◽  
Compensatory Mechanisms ◽  
Eye Field ◽  
The Brain ◽  
Saccade Generation

Both the frontal eye field (FEF) in the prefrontal cortex and the superior colliculus (SC) on the roof of the midbrain participate in the generation of rapid or saccadic eye movements and both have projections to the premotor circuits of the brain stem where saccades are ultimately generated. In the present experiments, we tested the contributions of the pathway from the FEF to the premotor circuitry in the brain stem that bypasses the SC. We assayed the contribution of the FEF to saccade generation by evoking saccades with direct electrical stimulation of the FEF. To test the role of the SC in conveying information to the brain stem, we inactivated the SC, thereby removing the circuit through the SC to the brain stem, and leaving only the direct FEF–brain stem pathway. If the contributions of the direct pathway were substantial, removal of the SC should have minimal effect on the FEF stimulation, whereas if the FEF stimulation were dependent on the SC, removal of the SC should alter the effect of FEF stimulation. By acutely inactivating the SC, instead of ablating it, we were able to test the efficiency of the direct FEF–brain stem pathway before substantial compensatory mechanisms could mask the effect of removing the SC. We found two striking effects of SC inactivation. In the first, we stimulated the FEF at a site that evoked saccades with vectors that were very close to those evoked at the site of the SC inactivation, and with such optimal alignment, we found that SC inactivation eliminated the saccades evoked by FEF stimulation. The second effect was evident when the FEF evoked saccades were disparate from those evoked in the SC, and in this case we observed a shift in the direction of the evoked saccade that was consistent with the SC inactivation removing a component of a vector average. Together these observations lead to the conclusion that in the nonablated monkey the direct FEF–brain stem pathway is not functionally sufficient to generate accurate saccades in the absence of the indirect pathway that courses from the FEF through the SC to the brain stem circuitry. We suggest that the recovery of function following SC ablation that has been seen in previous studies must result not from the use of an already functioning parallel pathway but from neural plasticity within the saccadic system.

The role of the right frontal eye field in overt visual attention deployment as assessed by free visual exploration

2015 ◽  
Vol 74 ◽  
pp. 37-41 ◽  
Author(s):  
Dario Cazzoli ◽  
Simon Jung ◽  
Thomas Nyffeler ◽  
Tobias Nef ◽  
Pascal Wurtz ◽  
...  
Keyword(s):  
Visual Attention ◽  
Visual Exploration ◽  
Frontal Eye Field ◽  
Eye Field ◽  
Attention Deployment ◽  
The Right

Frontoparietal Activation With Preparation for Antisaccades

2007 ◽  
Vol 98 (3) ◽  
pp. 1751-1762 ◽  
Author(s):  
Matthew R. G. Brown ◽  
Tutis Vilis ◽  
Stefan Everling
Keyword(s):  
Prefrontal Cortex ◽  
Anterior Cingulate Cortex ◽  
Human Subjects ◽  
Stimulus Presentation ◽  
Cingulate Cortex ◽  
Anterior Cingulate ◽  
Frontal Eye Field ◽  
Peripheral Stimulus ◽  
Supplementary Eye Field ◽  
Eye Field

Several current models hold that frontoparietal areas exert cognitive control by biasing task-relevant processing in other brain areas. Previous event-related functional magnetic resonance imaging (fMRI) studies have compared prosaccades and antisaccades, which require subjects to look toward or away from a flashed peripheral stimulus, respectively. These studies found greater activation for antisaccades in frontal and parietal regions at the ends of long (≥6 s) preparatory periods preceding peripheral stimulus presentation. Event-related fMRI studies using short preparatory periods (≤4 s) have not found such activation differences except in the frontal eye field. Here, we identified activation differences associated with short (1-s) preparatory periods by interleaving half trials among regular whole trials in a rapid fMRI design. On whole trials, a colored fixation dot instructed human subjects to make either a prosaccade toward or an antisaccade away from a peripheral visual stimulus. Half trials included only the instruction and not peripheral stimulus presentation or saccade generation. Nonetheless, half trials evoked stronger activation on antisaccades than on prosaccades in the frontal eye field (FEF), supplementary eye field (SEF), left dorsolateral prefrontal cortex (DLPFC), anterior cingulate cortex (ACC), intraparietal sulcus (IPS), and precuneus. Greater antisaccade response-related activation was found in FEF, SEF, IPS, and precuneus but not in DLPFC or ACC. These results demonstrate greater preparatory activation for antisaccades versus prosaccades in frontoparietal areas and suggest that prefrontal cortex and anterior cingulate cortex are more involved in presetting the saccade network for the antisaccade task than generating the actual antisaccade response.

Intracerebral dynamics of saccade generation in the human frontal eye field and supplementary eye field

NeuroImage ◽  
2006 ◽  
Vol 30 (4) ◽  
pp. 1302-1312 ◽  
Author(s):  
Jean-Philippe Lachaux ◽  
Dominique Hoffmann ◽  
Lorella Minotti ◽  
Alain Berthoz ◽  
Philippe Kahane
Keyword(s):  
Frontal Eye Field ◽  
Supplementary Eye Field ◽  
Eye Field ◽  
Saccade Generation

Neurocognitive Modeling of Perceptual Decision Making

2015 ◽  
Author(s):  
Thomas J. Palmeri ◽  
Jeffrey D. Schall ◽  
Gordon D. Logan
Keyword(s):  
Decision Making ◽  
Drift Rate ◽  
Response Times ◽  
Perceptual Processing ◽  
Mathematical Psychology ◽  
Frontal Eye Field ◽  
Perceptual Decision Making ◽  
Systems Neuroscience ◽  
Eye Field ◽  
Accumulator Models

Mathematical psychology and systems neuroscience have converged on stochastic accumulator models to explain decision making. We examined saccade decisions in monkeys while neurophysiological recordings were made within their frontal eye field. Accumulator models were tested on how well they fit response probabilities and distributions of response times to make saccades. We connected these models with neurophysiology. To test the hypothesis that visually responsive neurons represented perceptual evidence driving accumulation, we replaced perceptual processing time and drift rate parameters with recorded neurophysiology from those neurons. To test the hypothesis that movement related neurons instantiated the accumulator, we compared measures of neural dynamics with predicted measures of accumulator dynamics. Thus, neurophysiology both provides a constraint on model assumptions and data for model selection. We highlight a gated accumulator model that accounts for saccade behavior during visual search, predicts neurophysiology during search, and provides insights into the locus of cognitive control over decisions.

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