scholarly journals Effects of frontal eye field inactivation on visual responses of area V4 neurons

2010 ◽  
Vol 8 (6) ◽  
pp. 392-392
Author(s):  
B. Noudoost ◽  
T. Moore
Keyword(s):  
Frontal Eye Field ◽  
Visual Responses ◽  
Area V4 ◽  
Eye Field ◽  
V4 Neurons

Differential Temporal Storage Capacity in the Baseline Activity of Neurons in Macaque Frontal Eye Field and Area V4

2010 ◽  
Vol 103 (5) ◽  
pp. 2433-2445 ◽  
Author(s):  
Tadashi Ogawa ◽  
Hidehiko Komatsu
Keyword(s):  
Neuronal Activity ◽  
Storage Capacity ◽  
Discharge Rate ◽  
Time Lag ◽  
Temporal Correlation ◽  
Frontal Eye Field ◽  
Area V4 ◽  
Baseline Activity ◽  
Eye Field ◽  
V4 Neurons

Previous studies have suggested that spontaneous fluctuations in neuronal activity reflect intrinsic functional brain architecture. Inspired by these findings, we analyzed baseline neuronal activity in the monkey frontal eye field (FEF; a visuomotor area) and area V4 (a visual area) during the fixation period of a cognitive behavioral task in the absence of any task-specific stimuli or behaviors. Specifically, we examined the temporal storage capacity of the instantaneous discharge rate in FEF and V4 neurons by calculating the correlation of the spike count in a bin with that in another bin during the baseline activity of a trial. We found that most FEF neurons fired significantly more (or less) in one bin if they fired more (or less) in another bin within a trial, even when these two time bins were separated by hundreds of milliseconds. By contrast, similar long time-lag correlations were observed in only a small fraction of V4 neurons, indicating that temporal correlations were considerably stronger in FEF compared with those in V4 neurons. Additional analyses revealed that the findings were not attributable to other task-related variables or ongoing behavioral performance, suggesting that the differences in temporal correlation strength reflect differences in intrinsic structural and functional architecture between visual and visuomotor areas. Thus FEF neurons probably play a greater role than V4 neurons in neural circuits responsible for temporal storage in activity.

scholarly journals Disparity Sensitivity of Frontal Eye Field Neurons

2000 ◽  
Vol 83 (1) ◽  
pp. 625-629 ◽  
Author(s):  
Stefano Ferraina ◽  
Martin Paré ◽  
Robert H. Wurtz
Keyword(s):  
Eye Movements ◽  
Dimensional Space ◽  
Visual Stimuli ◽  
Three Dimensional ◽  
Frontal Eye Field ◽  
Visual Responses ◽  
Motor Processes ◽  
Uncrossed Disparity ◽  
Eye Field ◽  
Three Dimensional Space

Information about depth is necessary to generate saccades to visual stimuli located in three-dimensional space. To determine whether monkey frontal eye field (FEF) neurons play a role in the visuo-motor processes underlying this behavior, we studied their visual responses to stimuli at different disparities. Disparity sensitivity was tested from 3° of crossed disparity (near) to 3° degrees of uncrossed disparity (far). The responses of about two thirds of FEF visual and visuo-movement neurons were sensitive to disparity and showed a broad tuning in depth for near or far disparities. Early phasic and late tonic visual responses often displayed different disparity sensitivity. These findings provide evidence of depth-related signals in FEF and suggest a role for FEF in the control of disconjugate as well as conjugate eye movements.

scholarly journals What the Brain Stem Tells the Frontal Cortex. I. Oculomotor Signals Sent From Superior Colliculus to Frontal Eye Field Via Mediodorsal Thalamus

2004 ◽  
Vol 91 (3) ◽  
pp. 1381-1402 ◽  
Author(s):  
Marc A. Sommer ◽  
Robert H. Wurtz
Keyword(s):  
Superior Colliculus ◽  
Frontal Cortex ◽  
Brain Stem ◽  
Signal Transmission ◽  
Frontal Eye Field ◽  
Visual Responses ◽  
Mediodorsal Thalamus ◽  
Visual Activity ◽  
Eye Field ◽  
The Brain

Neuronal processing in cerebral cortex and signal transmission from cortex to brain stem have been studied extensively, but little is known about the numerous feedback pathways that ascend from brain stem to cortex. In this study, we characterized the signals conveyed through an ascending pathway coursing from the superior colliculus (SC) to the frontal eye field (FEF) via mediodorsal thalamus (MD). Using antidromic and orthodromic stimulation, we identified SC source neurons, MD relay neurons, and FEF recipient neurons of the pathway in Macaca mulatta. The monkeys performed oculomotor tasks, including delayed-saccade tasks, that permitted analysis of signals such as visual activity, delay activity, and presaccadic activity. We found that the SC sends all of these signals into the pathway with no output selectivity, i.e., the signals leaving the SC resembled those found generally within the SC. Visual activity arrived in FEF too late to contribute to short-latency visual responses there, and delay activity was largely filtered out in MD. Presaccadic activity, however, seemed critical because it traveled essentially unchanged from SC to FEF. Signal transmission in the pathway was fast (∼2 ms from SC to FEF) and topographically organized (SC neurons drove MD and FEF neurons having similarly eccentric visual and movement fields). Our analysis of identified neurons in one pathway from brain stem to frontal cortex thus demonstrates that multiple signals are sent from SC to FEF with presaccadic activity being prominent. We hypothesize that a major signal conveyed by the pathway is corollary discharge information about the vector of impending saccades.

scholarly journals Neural mechanisms of speed-accuracy tradeoff of visual search: Saccade vigor, targeting errors, superior colliculus and frontal eye field

2017 ◽  
Author(s):  
Thomas R. Reppert ◽  
Mathieu Servant ◽  
Richard P. Heitz ◽  
Jeffrey D. Schall
Keyword(s):  
Visual Search ◽  
Superior Colliculus ◽  
Time Course ◽  
Frontal Eye Field ◽  
Visual Responses ◽  
Response Preparation ◽  
Eye Field ◽  
Neurophysiological Mechanisms ◽  
Speed Accuracy ◽  
Accuracy Tradeoff

AbstractBalancing the speed-accuracy tradeoff (SAT) is necessary for successful behavior. Using a visual search task with interleaved cues emphasizing speed or accuracy, we recently reported diverse contributions of frontal eye field (FEF) neurons instantiating salience evidence and response preparation. Here we report replication of visual search SAT performance in two macaque monkeys, new information about variation of saccade dynamics with SAT, extension of the neurophysiological investigation to describe processes in the superior colliculus, and description of the origin of search errors in this task. Saccade vigor varied idiosyncratically across SAT conditions and monkeys, but tended to decrease with response time. As observed in the FEF, speed-accuracy tradeoff was accomplished through several distinct adjustments in the superior colliculus. Visually-responsive neurons modulated baseline firing rate and the time course of salience evidence. Unlike FEF, the magnitude of visual responses in SC did not vary across SAT conditions, but the time to locate the target was longer in Accurate as compared to Fast trials. Also unlike FEF, the activity of SC movement neurons when saccades were initiated was equivalent in Fast and Accurate trials. Search errors occurred when visual salience neurons in FEF and SC treated distractors as targets, even in the Accurate condition. Saccade-related neural activity in SC but less FEF varied with saccade peak velocity. These results extend our understanding of the cortical and subcortical contributions to SAT.Significance statementNeurophysiological mechanisms of speed-accuracy tradeoff (SAT) have only recently been investigated. This paper reports the first replication of SAT performance in nonhuman primates, the first report of variation of saccade dynamics with SAT, the first description of superior colliculus contributions to SAT, and the first description of the origin of errors during SAT. These results inform and constrain new models of distributed decision-making.

scholarly journals Integration of Eye-Centered and Landmark-Centered Codes in Frontal Eye Field Gaze Responses

2020 ◽  
Vol 30 (9) ◽  
pp. 4995-5013 ◽  
Author(s):  
Vishal Bharmauria ◽  
Amirsaman Sajad ◽  
Jirui Li ◽  
Xiaogang Yan ◽  
Hongying Wang ◽  
...  
Keyword(s):  
Frontal Cortex ◽  
Visual Information ◽  
Target Position ◽  
Frontal Eye Field ◽  
Visual Responses ◽  
Cellular Mechanisms ◽  
Behavioral Experiments ◽  
The Gaze ◽  
Field Activity ◽  
Eye Field

Abstract The visual system is thought to separate egocentric and allocentric representations, but behavioral experiments show that these codes are optimally integrated to influence goal-directed movements. To test if frontal cortex participates in this integration, we recorded primate frontal eye field activity during a cue-conflict memory delay saccade task. To dissociate egocentric and allocentric coordinates, we surreptitiously shifted a visual landmark during the delay period, causing saccades to deviate by 37% in the same direction. To assess the cellular mechanisms, we fit neural response fields against an egocentric (eye-centered target-to-gaze) continuum, and an allocentric shift (eye-to-landmark-centered) continuum. Initial visual responses best-fit target position. Motor responses (after the landmark shift) predicted future gaze position but embedded within the motor code was a 29% shift toward allocentric coordinates. This shift appeared transiently in memory-related visuomotor activity, and then reappeared in motor activity before saccades. Notably, fits along the egocentric and allocentric shift continua were initially independent, but became correlated across neurons just before the motor burst. Overall, these results implicate frontal cortex in the integration of egocentric and allocentric visual information for goal-directed action, and demonstrate the cell-specific, temporal progression of signal multiplexing for this process in the gaze system.

Dissociation of Visual Discrimination From Saccade Programming in Macaque Frontal Eye Field

1997 ◽  
Vol 77 (2) ◽  
pp. 1046-1050 ◽  
Author(s):  
Kirk G. Thompson ◽  
Narcisse P. Bichot ◽  
Jeffrey D. Schall
Keyword(s):  
Visual Search ◽  
Eye Movements ◽  
Visual Stimulus ◽  
Visual Discrimination ◽  
Time Course ◽  
Selection Process ◽  
Frontal Eye Field ◽  
Visual Responses ◽  
Eye Field ◽  
Saccade Programming

Thompson, Kirk G., Narcisse P. Bichot, and Jeffrey D. Schall. Dissociation of visual discrimination from saccade programming in macaque frontal eye field. J. Neurophysiol. 77: 1046–1050, 1997. To determine whether visual discrimination in macaque frontal eye field (FEF) is contingent on saccade planning, unit activity was recorded in two monkeys during blocked go and no-go visual search trials. The eye movements made by monkeys after correct no-go trials, in addition to an attenuation of the visual responses in no-go trials compared with go trials, indicated that covert saccade planning was effectively discouraged. During no-go search trials, the activity of the majority of neurons evolved to signal the location of the oddball stimulus. The degree and time course of the stimulus discrimination process observed in no-go trials was not different from that observed in go trials. We conclude that the discrimination of a salient visual stimulus reflected by FEF neurons is not contingent on saccade production but rather may reflect the outcome of an automatic visual selection process.

scholarly journals Feature-Based Attention in the Frontal Eye Field and Area V4 during Visual Search

Neuron ◽  
2011 ◽  
Vol 70 (6) ◽  
pp. 1205-1217 ◽  
Author(s):  
Huihui Zhou ◽  
Robert Desimone
Keyword(s):  
Visual Search ◽  
Frontal Eye Field ◽  
Area V4 ◽  
Eye Field ◽  
Feature Based

scholarly journals Radial motion bias in macaque frontal eye field

2006 ◽  
Vol 23 (1) ◽  
pp. 49-60 ◽  
Author(s):  
QUAN XIAO ◽  
ANDREI BARBORICA ◽  
VINCENT P. FERRERA
Keyword(s):  
Receptive Field ◽  
Optic Flow ◽  
Posterior Parietal Cortex ◽  
Population Level ◽  
Direction Selectivity ◽  
Frontal Eye Field ◽  
Visual Responses ◽  
Eye Field ◽  
Outward Motion ◽  
Random Dot Patterns

The visual responsiveness and spatial tuning of frontal eye field (FEF) neurons were determined using a delayed memory saccade task. Neurons with visual responses were then tested for direction selectivity using moving random dot patterns centered in the visual receptive field. The preferred axis of motion showed a significant tendency to be aligned with the receptive-field location so as to favor motion toward or away from the center of gaze. Centrifugal (outward) motion was preferred over centripetal motion. Motion-sensitive neurons in FEF thus appear to have a direction bias at the population level. This bias may facilitate the detection or discrimination of expanding optic flow patterns. The direction bias is similar to that seen in visual area MT and in posterior parietal cortex, from which FEF receives afferent projections. The outward motion bias may explain asymmetries in saccades made to moving targets. A representation of optic flow in FEF might be useful for planning eye movements during navigation.

scholarly journals Modulation of Visual Responses in Macaque Frontal Eye Field during Covert Tracking of Invisible Targets

2006 ◽  
Vol 17 (4) ◽  
pp. 918-928 ◽  
Author(s):  
Q. Xiao ◽  
A. Barborica ◽  
V. P. Ferrera
Keyword(s):  
Frontal Eye Field ◽  
Visual Responses ◽  
Eye Field
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