scholarly journals Coding of interceptive saccades in parietal cortex of macaque monkeys

2021 ◽  
Author(s):  
Jan Churan ◽  
Andre Kaminiarz ◽  
Jakob C.B. Schwenk ◽  
Frank Bremmer
Keyword(s):  
Oculomotor System ◽  
Saccade Target ◽  
Frontal Eye Field ◽  
Moving Target ◽  
Gaze Control ◽  
Moving Targets ◽  
Macaque Monkeys ◽  
Parietal Area ◽  
Eye Field ◽  
Target Selecting

The oculomotor system can initiate remarkably accurate saccades towards moving targets (interceptive saccades) the processing of which is still under debate. The generation of these saccades requires the oculomotor centers to have information about the motion parameters of the target that then must be extrapolated to bridge the inherent processing delays. We investigated to what degree the information about motion of a saccade target is available in the lateral intra-parietal area (area LIP) of macaque monkeys for generation of accurate interceptive saccades. When a multi-layer neural network was trained based on neural discharges from area LIP around the time of saccades towards stationary targets it was also able to predict the end points of saccades directed towards moving targets. This prediction, however, lagged behind the actual post-saccadic position of the moving target by ~80 ms when the whole neuronal sample of 105 neurons was used. We further found that single neurons differentially code for the motion of the target. Selecting neurons with the strongest representation of target motion reduced this lag to ~30 ms which represents the position of the moving target approximately at the onset of the interceptive saccade. We conclude that - similarly to recent findings from the Superior Colliculus (Goffart et al., 2017) - there is a continuum of contributions of individual LIP neurons to the accuracy of interceptive saccades. A contribution of other gaze control centers (like the cerebellum or the frontal eye field) that further increase the saccadic accuracy is, however, likely.

scholarly journals Coding of interceptive saccades in parietal cortex of macaque monkeys

2021 ◽  
Author(s):  
Jan Churan ◽  
Andre Kaminiarz ◽  
Jakob C. B. Schwenk ◽  
Frank Bremmer
Keyword(s):  
Oculomotor System ◽  
Saccade Target ◽  
Frontal Eye Field ◽  
Moving Target ◽  
Gaze Control ◽  
Moving Targets ◽  
Macaque Monkeys ◽  
Parietal Area ◽  
Eye Field ◽  
Target Selecting

AbstractThe oculomotor system can initiate remarkably accurate saccades towards moving targets (interceptive saccades) the processing of which is still under debate. The generation of these saccades requires the oculomotor centers to have information about the motion parameters of the target that then must be extrapolated to bridge the inherent processing delays. We investigated to what degree the information about motion of a saccade target is available in the lateral intra-parietal area (area LIP) of macaque monkeys for generation of accurate interceptive saccades. When a multi-layer neural network was trained based on neural discharges from area LIP around the time of saccades towards stationary targets, it was also able to predict the end points of saccades directed towards moving targets. This prediction, however, lagged behind the actual post-saccadic position of the moving target by ~ 80 ms when the whole neuronal sample of 105 neurons was used. We further found that single neurons differentially code for the motion of the target. Selecting neurons with the strongest representation of target motion reduced this lag to ~ 30 ms which represents the position of the moving target approximately at the onset of the interceptive saccade. We conclude that—similarly to recent findings from the Superior Colliculus (Goffart et al. J Neurophysiol 118(5):2890–2901)—there is a continuum of contributions of individual LIP neurons to the accuracy of interceptive saccades. A contribution of other gaze control centers (like the cerebellum or the frontal eye field) that further increase the saccadic accuracy is, however, likely.

scholarly journals Salience by Competitive and Recurrent Interactions: Bridging Neural Spiking and Computation

2021 ◽  
Author(s):  
Gregory Edward Cox ◽  
Thomas Palmeri ◽  
Gordon D. Logan ◽  
Philip L. Smith ◽  
Jeffrey Schall
Keyword(s):  
Decision Making ◽  
Response Times ◽  
Target Selection ◽  
Interaction Model ◽  
Saccade Target ◽  
Frontal Eye Field ◽  
Visual Neurons ◽  
Discharge Rates ◽  
Neural Spiking ◽  
Eye Field

Decisions about where to move the eyes depend on neurons in Frontal Eye Field (FEF). Movement neurons in FEF accumulate salience evidence derived from FEF visual neurons to select the location of a saccade target among distractors. How visual neurons achieve this salience representation is unknown. We present a neuro-computational model of target selection called Salience by Competitive and Recurrent Interactions (SCRI), based on the Competitive Interaction model of attentional selection and decision making (Smith & Sewell, 2013). SCRI selects targets by synthesizing localization and identification information to yield a dynamically evolving representation of salience across the visual field. SCRI accounts for neural spiking of individual FEF visual neurons, explaining idiosyncratic differences in neural dynamics with specific parameters. Many visual neurons resolve the competition between search items through feedforward inhibition between signals representing different search items, some also require lateral inhibition, and many act as recurrent gates to modulate the incoming flow of information about stimulus identity. SCRI was tested further by using simulated spiking representations of visual salience as input to the Gated Accumulator Model of FEF movement neurons (Purcell et al., 2010; Purcell, Schall, Logan, & Palmeri, 2012). Predicted saccade response times fit those observed for search arrays of different set size and different target-distractor similarity, and accumulator trajectories replicated movement neuron discharge rates. These findings offer new insights into visual decision making through converging neuro-computational constraints and provide a novel computational account of the diversity of FEF visual neurons.

scholarly journals Shape Selectivity in Primate Frontal Eye Field

2008 ◽  
Vol 100 (2) ◽  
pp. 796-814 ◽  
Author(s):  
Xinmiao Peng ◽  
Margaret E. Sereno ◽  
Amanda K. Silva ◽  
Sidney R. Lehky ◽  
Anne B. Sereno
Keyword(s):  
Functional Organization ◽  
Target Selection ◽  
Visual Stimuli ◽  
Shape Selectivity ◽  
Saccade Target ◽  
Frontal Eye Field ◽  
Gaze Shift ◽  
Match To Sample ◽  
Neurophysiological Studies ◽  
Eye Field

Previous neurophysiological studies of the frontal eye field (FEF) in monkeys have focused on its role in saccade target selection and gaze shift control. It has been argued that FEF neurons indicate the locations of behaviorally significant visual stimuli and are not inherently sensitive to specific features of the visual stimuli per se. Here, for the first time, we directly examined single cell responses to simple, two-dimensional shapes and found that shape selectivity exists in a substantial number of FEF cells during a passive fixation task or during the sample, delay (memory), and eye movement periods in a delayed match to sample (DMTS) task. Our data demonstrate that FEF neurons show sensory and mnemonic selectivity for stimulus shape features whether or not they are behaviorally significant for the task at hand. We also investigated the extent and localization of activation in the FEF using a variety of shape stimuli defined by static or dynamic cues employing functional magentic resonance imaging (fMRI) in anesthetized and paralyzed monkeys. Our fMRI results support the electrophysiological findings by showing significant FEF activation for a variety of shape stimuli and cues in the absence of attentional and motor processing. This shape selectivity in FEF is comparable to previous reports in the ventral pathway, inviting a reconsideration of the functional organization of the visual system.

scholarly journals A Comparison of Frontoparietal fMRI Activation During Anti-Saccades and Anti-Pointing

2000 ◽  
Vol 84 (3) ◽  
pp. 1645-1655 ◽  
Author(s):  
Jason D. Connolly ◽  
Melvyn A. Goodale ◽  
Joseph F. X. Desouza ◽  
Ravi S. Menon ◽  
Tutis Vilis ◽  
...  
Keyword(s):  
Supplementary Motor Area ◽  
Orienting Response ◽  
Anterior Cingulate ◽  
Frontal Eye Field ◽  
Response Suppression ◽  
Medial Region ◽  
Frontoparietal Network ◽  
Parietal Area ◽  
Eye Field ◽  
Anti Saccades

An anti-saccade, which is a saccade directed toward a mirror-symmetrical position in the opposite visual field relative to the visual stimulus, involves at least three separate operations: covert orienting, response suppression, and coordinate transformation. The distinction between pro- and anti-saccades can also be applied to pointing. We used fMRI to compare patterns of brain activation during pro- and anti-movements, to determine whether or not additional areas become active during the production of anti-movements. In parietal cortex, an inferior network was active during both saccades and pointing that included three foci along the intraparietal sulcus: 1) a posterior superior parietal area (pSPR), more active during the anti-tasks; 2) a middle inferior parietal area (mIPR), active only during the anti-tasks; and 3) an anterior inferior parietal area (aIPR), equally active for pro- and anti-movement. A superior parietal network was active during pointing but not saccades and included the following: 1) a medial region, active during anti- but not pro-pointing (mSPR); 2) an anterior and medial region, more active during pro-pointing (aSPR); and 3) an anterior and lateral region, equally active for pro- and anti-pointing (lSPR). In frontal cortex, areas selectively active during anti-movement were adjacent and anterior to areas that were active during both the anti- and pro-tasks, i.e., were anterior to the frontal eye field and the supplementary motor area. All saccade areas were also active during pointing. In contrast, foci in the dorsal premotor area, the anterior superior frontal region, and anterior cingulate were active during pointing but not saccades. In summary, pointing with central gaze activates a frontoparietal network that includes the saccade network. The operations required for the production of anti-movements recruited additional frontoparietal areas.

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.

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.

Corticocortical input to the smooth and saccadic eye movement subregions of the frontal eye field in Cebus monkeys

1996 ◽  
Vol 76 (4) ◽  
pp. 2754-2771 ◽  
Author(s):  
J. R. Tian ◽  
J. C. Lynch
Keyword(s):  
Eye Movement ◽  
Frontal Eye Field ◽  
Adjacent Area ◽  
Saccadic Eye Movement ◽  
Temporal Area ◽  
Macaque Monkeys ◽  
Supplementary Eye Field ◽  
Eye Field ◽  
Cebus Monkeys ◽  
The One

1. The locations and connections of the smooth and saccadic eye movement subregions of the frontal eye field (FEFsem and FEFsac, respectively) were investigated in seven hemispheres of five Cebus monkeys. The supplementary eye field was also mapped in seven hemispheres and the hand/arm regions of the dorsal and ventral premotor areas were localized in five hemispheres. Monkeys were immobilized during experiments with Telazol, a dissociative anesthetic agent that has no significant effect on microstimulation-induced eye movement parameters (threshold, velocity, and duration). The functional subregions were defined with the use of low threshold intracortical microstimulation (current < or = 50 microA). Then different retrogradely transported fluorescent tracers were placed into these functionally defined regions. 2. The FEFsac in Cebus monkey is in the same location as the one in macaque monkeys, which is in Walker's areas 8a and 45. The FEFsem is located in the posterior shoulder of the superior arcuate sulcus near its medial tip and is therefore more accessible for tracer injections than the one in macaque monkeys. This subregion is within cytoarchitectural area 6a beta, which is distinct from the adjacent area 6a alpha (dorsal premotor area). This smooth eye movement subregion may be comparable with the one in macaque monkeys. 3. Cortical connection patterns of the FEFsac and FEFsem are similar and parallel to each other. The predominant neural input to these two subregions originates in other cortical eye fields, including the supplementary eye field, the parietal eye field, the middle superior temporal area, and the principal sulcus region. These cortical eye fields each contain two separate, almost non-overlapping, distributions of labeled neurons that project to the corresponding frontal eye field (FEF) subregions. These results suggest that there may be similar, but relatively independent, parallel corticocortical networks to control pursuit and saccadic eye movements. The weak connections between the middle temporal area (MT) and FEF suggest that the MT may not provide the major source of visuomotion inputs to the FEF, but that it rather plays a role in mediating visual information that is relayed from the striate and extrastriate cortices via MT to the parietal cortex and then to the FEF. In addition to the well-known neural connections between the lateral intraparietal area and the FEF, additional parietal projections have been demonstrated from the dorsomedial visual area area specifically to the FEFsac and from area 7m specifically to the FEFsem.

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