scholarly journals Reward-driven modulation of spatial attention in the human frontal eye-field

NeuroImage ◽  
2021 ◽  
pp. 118846
Author(s):  
Alexia Bourgeois ◽  
Virginie Sterpenich ◽  
Giannina Rita Iannotti ◽  
Patrik Vuilleumier
Keyword(s):  
Spatial Attention ◽  
Frontal Eye Field ◽  
Eye Field

scholarly journals Functional localization of the frontal eye fields in the common marmoset using microstimulation

2019 ◽  
Author(s):  
Janahan Selvanayagam ◽  
Kevin D. Johnston ◽  
David J. Schaeffer ◽  
Lauren K. Hayrynen ◽  
Stefan Everling
Keyword(s):  
Spatial Attention ◽  
Common Marmoset ◽  
Frontal Eye Field ◽  
Cortical Region ◽  
Compelling Evidence ◽  
Primate Model ◽  
Promising Alternative ◽  
Cortical Areas ◽  
Eye Field ◽  
The Common

AbstractThe frontal eye field (FEF) is a critical region for the deployment of overt and covert spatial attention. While investigations in the macaque continue to provide insight into the neural underpinnings of the FEF, due to its location within a sulcus the macaque FEF is virtually inaccessible to electrophysiological techniques such as high-density and laminar recordings. With a largely lissencephalic cortex, the common marmoset (Callithrix jacchus) is a promising alternative primate model for studying FEF microcircuitry. Putative homologies have been established with the macaque FEF on the basis of cytoarchitecture and connectivity, however physiological investigation in awake, behaving marmosets is necessary to physiologically locate this area. Here we addressed this gap using intracortical microstimulation in a broad range of frontal cortical areas in marmosets. We implanted marmosets with 96-channel Utah arrays and applied microstimulation trains while they freely viewed video clips. We evoked short-latency fixed vector saccades at low currents (<50 μA) in areas 45, 8aV, 8C and 6DR. We observed a topography of saccade direction and amplitude consistent with findings in macaques and humans; we observed small saccades in ventrolateral FEF and large saccades combined with contralateral neck and shoulder movements encoded in dorsomedial FEF. Our data provide compelling evidence supporting homology between marmoset and macaque FEF and suggest the marmoset is a useful primate model for investigating FEF microcircuitry and its contributions to oculomotor and cognitive functions.Significance StatementThe frontal eye field (FEF) is a critical cortical region for overt and covert spatial attention. The microcircuitry of this area remains poorly understood, as in the macaque, the most commonly used model, it is embedded within a sulcus and is inaccessible to modern electrophysiological and optical imaging techniques. The common marmoset is a promising alternative primate model due to its lissencephalic cortex and potential for genetic manipulation. However, evidence for homologous cortical areas in this model remains limited and unclear. Here we applied microstimulation in frontal cortical areas in marmosets to physiologically identify the FEF. Our results provide compelling evidence for a frontal eye field in the marmoset, and suggest that the marmoset is a useful model for FEF microcircuitry.

Neuronal Mechanisms of Attentional Control

2014 ◽  
Author(s):  
Kelsey L. Clark ◽  
Behrad Noudoost ◽  
Robert J. Schafer ◽  
Tirin Moore
Keyword(s):  
Spatial Attention ◽  
Covert Attention ◽  
Extrastriate Cortex ◽  
Frontal Eye Field ◽  
Neural Signals ◽  
Electrical Microstimulation ◽  
Visual Spatial ◽  
Neuronal Mechanisms ◽  
Eye Field ◽  
Visual Cortical

Covert spatial attention prioritizes the processing of stimuli at a given peripheral location, away from the direction of gaze, and selectively enhances visual discrimination, speed of processing, contrast sensitivity, and spatial resolution at the attended location. While correlates of this type of attention, which are believed to underlie perceptual benefits, have been found in a variety of visual cortical areas, more recent observations suggest that these effects may originate from frontal and parietal areas. Evidence for a causal role in attention is especially robust for the Frontal Eye Field, an oculomotor area within the prefrontal cortex. FEF firing rates have been shown to reflect the location of voluntarily deployed covert attention in a variety of tasks, and these changes in firing rate precede those observed in extrastriate cortex. In addition, manipulation of FEF activity—whether via electrical microstimulation, pharmacologically, or operant conditioning—can produce attention-like effects on behaviour and can modulate neural signals within posterior visual areas. We review this evidence and discuss the role of the FEF in visual spatial attention.

scholarly journals Frontal Eye Field Activity Enhances Object Identification During Covert Visual Search

2009 ◽  
Vol 102 (6) ◽  
pp. 3656-3672 ◽  
Author(s):  
Ilya E. Monosov ◽  
Kirk G. Thompson
Keyword(s):  
Visual Search ◽  
Spatial Attention ◽  
Visual Processing ◽  
Target Location ◽  
Target Identification ◽  
Object Identification ◽  
Frontal Eye Field ◽  
Search Array ◽  
Functional Link ◽  
Eye Field

We investigated the link between neuronal activity in the frontal eye field (FEF) and the enhancement of visual processing associated with covert spatial attention in the absence of eye movements. We correlated activity recorded in the FEF of monkeys manually reporting the identity of a visual search target to performance accuracy and reaction time. Monkeys were cued to the most probable target location with a cue array containing a popout color singleton. Neurons exhibited spatially selective responses for the popout cue stimulus and for the target of the search array. The magnitude of activity related to the location of the cue prior to the presentation of the search array was correlated with trends in behavioral performance across valid, invalid, and neutral cue trial conditions. However, the speed and accuracy of the behavioral report on individual trials were predicted by the magnitude of spatial selectivity related to the target to be identified, not for the spatial cue. A minimum level of selectivity was necessary for target detection and a higher level for target identification. Muscimol inactivation of FEF produced spatially selective perceptual deficits in the covert search task that were correlated with the effectiveness of the inactivation and were strongest on invalid cue trials that require an endogenous attention shift. These results demonstrate a strong functional link between FEF activity and covert spatial attention and suggest that spatial signals from FEF directly influence visual processing during the time that a stimulus to be identified is being processed by the visual system.

scholarly journals No evidence that frontal eye field tDCS affects latency or accuracy of prosaccades

2018 ◽  
Author(s):  
Leon C. Reteig ◽  
Tomas Knapen ◽  
Floris J.F.W. Roelofs ◽  
K. Richard Ridderinkhof ◽  
Heleen A. Slagter
Keyword(s):  
Eye Movements ◽  
Spatial Attention ◽  
Saccadic Eye Movements ◽  
Sudden Onset ◽  
Frontal Eye Field ◽  
Physiological Mechanisms ◽  
Double Blind ◽  
Future Studies ◽  
Cathodal Tdcs ◽  
Eye Field

AbstractTranscranial direct current stimulation (tDCS) may be used to directly affect neural activity from outside of the skull. However, its exact physiological mechanisms remain elusive, particularly when applied to new brain areas. The frontal eye field (FEF) has rarely been targeted with tDCS, even though it plays a crucial role in control of overt and covert spatial attention. Here we investigate whether tDCS over the FEF can affect the latency and accuracy of saccadic eye movements. 26 participants performed a prosaccade task in which they made eye movements to a sudden-onset eccentric visual target (lateral saccades). After each lateral saccade, they made an eye movement back to the center (center saccades). The task was administered before, during and after anodal or cathodal tDCS over the FEF, in a randomized, double-blind, within-subject design. One previous study (Kanai et al., 2012) found that anodal tDCS over the FEF decreased the latency of saccades contralateral to the stimulated hemisphere. We did not find the same effect: neither anodal nor cathodal tDCS influenced the latency of lateral saccades. tDCS also did not affect accuracy of lateral saccades (saccade endpoint deviation and saccade endpoint variability). For center saccades, we found some differences between the anodal and cathodal sessions, but these were not consistent across analyses (latency, endpoint variability), or were already present before tDCS onset (endpoint deviation). We tried to improve on the design of Kanai et al. (2012) in several ways, including the tDCS duration and electrode montage, which could explain the discrepant results. Our findings add to a growing number of null results, which have sparked concerns that tDCS outcomes are highly variable. Future studies should aim to establish the boundary conditions for frontal eye field tDCS to be effective, in addition to increasing sample size and adding additional controls such as a sham condition. At present, we conclude that it is unclear whether eye movements or other aspects of spatial attention can be affected through tDCS of the frontal eye fields.

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