scholarly journals Entrainment of local synchrony reveals a causal role for high-beta right frontal oscillations in human visual consciousness

2019 ◽  
Author(s):  
Marine Vernet ◽  
Chloé Stengel ◽  
Romain Quentin ◽  
Julià L. Amengual ◽  
Antoni Valero-Cabré
Keyword(s):  
Visual Detection ◽  
Critical Role ◽  
Causal Link ◽  
Oscillatory Activity ◽  
Frontal Eye Field ◽  
Phase Alignment ◽  
Visual Behaviors ◽  
Eye Field ◽  
The Right ◽  
High Beta

AbstractPrior evidence supports the critical role of oscillatory activity in cognitive function, but are cerebral oscillations simply correlated or causally linked to specific aspects of visual cognition? Here, EEG signals were recorded on humans performing a conscious visual detection task, while they received briefrhythmicorrandomnoninvasive stimulation patterns delivered to the right Frontal Eye Field prior to the onset of a lateralized target. Compared torandompatterns,rhythmichigh-beta patterns led to greater entrainment of local oscillations (i.e., increased power and phase alignment at the stimulation frequency), and to higher conscious detection of contralateral targets. When stimulation succeeded in enhancing visual detection, the magnitude of oscillation entrainment correlated with visual performance increases. Our study demonstrates a causal link between high-beta oscillatory activity in the Frontal Eye Field and conscious visual perception. Furthermore, it supports future applications of brain stimulation to manipulate local synchrony and improve or restore impaired visual behaviors.

scholarly journals Entrainment of local synchrony reveals a causal role for high-beta right frontal oscillations in human visual consciousness

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Marine Vernet ◽  
Chloé Stengel ◽  
Romain Quentin ◽  
Julià L. Amengual ◽  
Antoni Valero-Cabré
Keyword(s):  
Visual Detection ◽  
Critical Role ◽  
Causal Link ◽  
Detection Sensitivity ◽  
Oscillatory Activity ◽  
Frontal Eye Field ◽  
Beta Power ◽  
Phase Alignment ◽  
Eye Field ◽  
High Beta

Abstract Prior evidence supports a critical role of oscillatory activity in visual cognition, but are cerebral oscillations simply correlated or causally linked to our ability to consciously acknowledge the presence of a target in our visual field? Here, EEG signals were recorded on humans performing a visual detection task, while they received brief patterns of rhythmic or random transcranial magnetic stimulation (TMS) delivered to the right Frontal Eye Field (FEF) prior to the onset of a lateralized target. TMS entrained oscillations, i.e., increased high-beta power and phase alignment (the latter to a higher extent for rhythmic high-beta patterns than random patterns) while also boosting visual detection sensitivity. Considering post-hoc only those participants in which rhythmic stimulation enhanced visual detection, the magnitude of high-beta entrainment correlated with left visual performance increases. Our study provides evidence in favor of a causal link between high-beta oscillatory activity in the Frontal Eye Field and visual detection. Furthermore, it supports future applications of brain stimulation to manipulate local synchrony and improve or restore impaired visual behaviors.

scholarly journals Causal modulation of right hemisphere fronto-parietal phase synchrony with Transcranial Magnetic Stimulation during a conscious visual detection task

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chloé Stengel ◽  
Marine Vernet ◽  
Julià L. Amengual ◽  
Antoni Valero-Cabré
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Visual Perception ◽  
Frequency Band ◽  
Magnetic Stimulation ◽  
Visual Detection ◽  
Detection Task ◽  
Oscillatory Activity ◽  
Top Down ◽  
The Right ◽  
High Beta

AbstractCorrelational evidence in non-human primates has reported increases of fronto-parietal high-beta (22–30 Hz) synchrony during the top-down allocation of visuo-spatial attention. But may inter-regional synchronization at this specific frequency band provide a causal mechanism by which top-down attentional processes facilitate conscious visual perception? To address this question, we analyzed electroencephalographic (EEG) signals from a group of healthy participants who performed a conscious visual detection task while we delivered brief (4 pulses) rhythmic (30 Hz) or random bursts of Transcranial Magnetic Stimulation (TMS) to the right Frontal Eye Field (FEF) prior to the onset of a lateralized target. We report increases of inter-regional synchronization in the high-beta band (25–35 Hz) between the electrode closest to the stimulated region (the right FEF) and right parietal EEG leads, and increases of local inter-trial coherence within the same frequency band over bilateral parietal EEG contacts, both driven by rhythmic but not random TMS patterns. Such increases were accompained by improvements of conscious visual sensitivity for left visual targets in the rhythmic but not the random TMS condition. These outcomes suggest that high-beta inter-regional synchrony can be modulated non-invasively and that high-beta oscillatory activity across the right dorsal fronto-parietal network may contribute to the facilitation of conscious visual perception. Our work supports future applications of non-invasive brain stimulation to restore impaired visually-guided behaviors by operating on top-down attentional modulatory mechanisms.

Transcranial Magnetic Stimulation of the Human Frontal Eye Field: Effects on Visual Perception and Attention

2002 ◽  
Vol 14 (7) ◽  
pp. 1109-1120 ◽  
Author(s):  
Marie-Hélène Grosbras ◽  
Tomáš Paus
Keyword(s):  
Eye Movements ◽  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Right Hemisphere ◽  
Visual Detection ◽  
Frontal Eye Field ◽  
Target Onset ◽  
Eye Field ◽  
The Right

When looking at one object, human subjects can shift their attention to another object in their visual field without moving the eyes. Such shifts of attention activate the same brain regions as those involved in the execution of eye movements. Here we investigate the role of one of the main cortical oculomotor area, namely, the frontal eye field (FEF), in shifts of attention. We used transcranial magnetic stimulation (TMS), a technique known to disrupt transiently eye-movements preparation. We hypothesized that if the FEF is a necessary element in the network involved in shifting attention without moving the eyes, then TMS should also disrupt visuospatial attention. For each volunteer, we positioned the TMS coil over the probabilistic anatomical location of the FEF, and we verified that single pulses delayed eye movements. We then applied TMS during a visuospatial attention task. In this task, a central arrow directed shifts of attention and the subject responded by a keypress to a subsequent visual peripheral target without moving the eyes from the central fixation point. In a few trials, the cue was invalid or uninformative, yielding slower responses than when the cue was valid. We delivered single pulses either 53 msec before or 70 msec after target onset. Contrary to our prediction, the main effect of the stimulation was a decrease in reaction time when it was applied 53 msec before target onset. TMS over the left hemisphere facilitated responses to targets in the right hemifield only and for all cueing conditions, whereas TMS over the right hemisphere had a bilateral effect for valid and neutral but not invalid cueing. Thus, TMS interfered with shift of attention only in the case of right hemisphere stimulation: it increased the cost of invalid cueing. Our results suggest that TMS over the FEF facilitates visual detection, and thereby reduces reaction time. This finding provides new insights into the role of the human FEF in processing visual information. The functional asymmetry observed for both facilitation of visual detection and interference with shifts of attention provides further evidence for the dominance of the right hemisphere for those processes. Our results also underline that the disruptive or facilitative effect of TMS over a given region depends upon the behavioral context.

scholarly journals Causal modulation of right fronto-parietal phase synchrony with Transcranial Magnetic Stimulation during a conscious visual detection task

2019 ◽  
Author(s):  
Chloé Stengel ◽  
Marine Vernet ◽  
Julià L. Amengual ◽  
Antoni Valero-Cabré
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Frequency Band ◽  
Magnetic Stimulation ◽  
Visual Detection ◽  
Detection Task ◽  
Oscillatory Activity ◽  
Beta Band ◽  
The Right ◽  
High Beta ◽  
Regional Synchrony

AbstractCorrelational evidence in non-human primates has reported evidence of increased frontoparietal high-beta band (22-30 Hz) synchrony during the endogenous allocation of visuospatial attention. But may the engagement of inter-regional synchrony at this specific frequency band provide the causal mechanism by which top-down processes are engaged and they facilitate visual perception in humans? Here we further analyzed electroencephalographic (EEG) signals from a group of healthy human participants who performed a conscious visual detection task, under the influence of brief rhythmic (30 Hz) or random bursts of Transcranial Magnetic Stimulation (TMS), with an identical number of pulses and duration, delivered to the right Frontal Eye Field (FEF) prior to the onset of a lateralized near-threshold target. We report increases of inter-regional synchronization in the high-beta band (25-35 Hz) between the electrode closest to the stimulated region (right FEF) and parietal leads, and increases of local inter-trial coherence in the same frequency band over parietal contacts, both driven by rhythmic but not random TMS patterns. Importantly, such increases were accompained by increases of visual sensitivity for left visual targets (contralateral to the stimulation) in the rhythmic but not the random TMS condition at the group level. These outcomes suggest that human high-beta synchrony between right frontal and parietal regions can be modulated non-invasively and that high-beta oscillatory activity across the right dorsal fronto-parietal network may contribute to the facilitation of conscious visual detection. Our study also supports future applications of non-invasive brain stimulation technologies for the manipulation of inter-regional synchrony, which could be administered to improve visual behaviors in healthy humans or neurological patients.

scholarly journals Neural Control of Voluntary Eye Closure: A Case Study and an fMRI Investigation of Blinking and Winking

2012 ◽  
Vol 25 (2) ◽  
pp. 103-109 ◽  
Author(s):  
Martijn G. van Koningsbruggen ◽  
Marius V. Peelen ◽  
Eilir Davies ◽  
Robert D. Rafal
Keyword(s):  
Motor Cortex ◽  
Neural Control ◽  
Posterior Parietal Cortex ◽  
Critical Role ◽  
Neural Mechanisms ◽  
Frontal Eye Field ◽  
Supplementary Eye Field ◽  
Eye Field ◽  
The Right ◽  
Eye Closure

The current paper describes a rare case of a patient who suffered from unilateral apraxia of eye closure as a result of a bilateral stroke. Interestingly, the patient’s ability to voluntarily close both eyelids (i.e. blinking) was not affected, indicating that different neural mechanisms control each type of eye closure. The stroke caused damage to a large part of the right frontal cortex, including the motor cortex, pre-motor cortex and the frontal eye field (FEF). The lesion in the left hemisphere was restricted to the FEF. In order to further study the neural mechanisms of eye closure, we conducted an fMRI study in a group of neurological healthy subjects. We found that all areas of the oculomotor cortex were activated by both left and right winking, including the FEF, supplementary eye field (SEF), and posterior parietal cortex (PPC). Blinking activated FEF and SEF, but not PPC. Both FEF and PPC were significantly more active during winking than blinking. Together, these results provide evidence for a critical role of the FEF in voluntary unilateral eye closure.

scholarly journals Gaze Palsy as a Manifestation of Todd’s Phenomenon: Case Report and Review of the Literature

2020 ◽  
Vol 10 (5) ◽  
pp. 298
Author(s):  
Karmele Olaciregui Dague ◽  
Manuel Dafotakis ◽  
Jörg B. Schulz ◽  
Rainer Surges
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Clonic Seizure ◽  
Frontal Eye Field ◽  
Correct Identification ◽  
Eye Field ◽  
Narrative Literature Review ◽  
Stroke Mimic ◽  
Therapeutic Decision Making ◽  
The Right ◽  
Gaze Palsy

Background: Though Todd’s phenomenon (TP) is a relatively rare occurrence, its correct identification is of key diagnostic and therapeutic importance as a stroke mimic. Here we describe a case of isolated gaze palsy as a manifestation of TP, discuss periictal gaze abnormalities as lateralizing sign involving the frontal eye field (FEF), and present a narrative literature review. Methods: We reviewed the main features of the case and conducted a structured literature search of TP and gaze palsy using PubMed. We restricted the search to publications in English, Spanish, French, and German. Case presentation: A 71-year-old male with a history of right frontotemporal subarachnoid hemorrhage was admitted to the Emergency Department of our institution after suffering a first unprovoked focal to bilateral tonic-clonic seizure with ictal gaze deviation to the left. Cranial imaging showed no signs of ischemia, intracerebral hemorrhage, or tumor. The patient presented the following postictal features: involuntary eye deviation to the right due to left-sided gaze palsy and disorientation in time with preserved responsiveness. Eye movements were normal three days later. We concluded that the patient suffered from new-onset epilepsy due to sequelae following the right frontotemporal subarachnoid hemorrhage, affecting the FEF with contralateral ictal gaze deviation, and postictal gaze palsy with ipsilateral eye deviation as an unusual Todd’s phenomenon. Conclusion: Unusual manifestations of TP are uncommon but clinically highly relevant, as they can mimic stroke or epileptic status and are decisive in the diagnostic and therapeutic decision-making process. Though postictal gaze palsy has been reported associated with other deficits, this constitutes, to our knowledge, the first report of isolated gaze palsy as a form of TP. Further research into the underlying causes is needed. Ictal contralateral gaze and head deviation, and probably postictal ipsilateral gaze deviation if present, are very helpful for the lateralization of the seizure-onset zone.

scholarly journals Occipital activations and deactivations induced by stimulation of the right human frontal eye field

2010 ◽  
Vol 5 (8) ◽  
pp. 365-365
Author(s):  
C. C. Ruff ◽  
F. Blankenburg ◽  
O. Bjoertomt ◽  
S. Bestmann ◽  
J.-D. Haynes ◽  
...  
Keyword(s):  
Frontal Eye Field ◽  
Eye Field ◽  
The Right ◽  
Stimulation Of

scholarly journals Right frontal eye field has perceptual and oculomotor functions during optokinetic stimulation and nystagmus

2020 ◽  
Vol 123 (2) ◽  
pp. 571-586 ◽  
Author(s):  
Angela Mastropasqua ◽  
James Dowsett ◽  
Marianne Dieterich ◽  
Paul C. J. Taylor
Keyword(s):  
Eye Movements ◽  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Visual Motion ◽  
Optokinetic Nystagmus ◽  
Frontal Eye Field ◽  
Optokinetic Stimulation ◽  
Motion Discrimination ◽  
Eye Field ◽  
The Right

The right frontal eye field (rFEF) is associated with visual perception and eye movements. rFEF is activated during optokinetic nystagmus (OKN), a reflex that moves the eye in response to visual motion (optokinetic stimulation, OKS). It remains unclear whether rFEF plays causal perceptual and/or oculomotor roles during OKS and OKN. To test this, participants viewed a leftward-moving visual scene of vertical bars and judged whether a flashed dot was moving. Single pulses of transcranial magnetic stimulation (TMS) were applied to rFEF on half of trials. In half of blocks, to explore oculomotor control, participants performed an OKN in response to the OKS. rFEF TMS, during OKN, made participants more accurate on trials when the dot was still, and it slowed eye movements. In separate blocks, participants fixated during OKS. This not only controlled for eye movements but also allowed the use of EEG to explore the FEF’s role in visual motion discrimination. In these blocks, by contrast, leftward dot motion discrimination was impaired, associated with a disruption of the frontal-posterior balance in alpha-band oscillations. None of these effects occurred in a control site (M1) experiment. These results demonstrate multiple related yet dissociable causal roles of the right FEF during optokinetic stimulation. NEW & NOTEWORTHY This study demonstrates causal roles of the right frontal eye field (FEF) in motion discrimination and eye movement control during visual scene motion: previous work had only examined other stimuli and eye movements such as saccades. Using combined transcranial magnetic stimulation and EEG and a novel optokinetic stimulation motion-discrimination task, we find evidence for multiple related yet dissociable causal roles within the FEF: perceptual processing during optokinetic stimulation, generation of the optokinetic nystagmus, and the maintenance of alpha oscillations.

scholarly journals Temporal dynamics of retinal and extraretinal signals in the FEFsem during smooth pursuit eye movements

2017 ◽  
Vol 117 (5) ◽  
pp. 1987-2003 ◽  
Author(s):  
Leah Bakst ◽  
Jérome Fleuriet ◽  
Michael J. Mustari
Keyword(s):  
Eye Movements ◽  
Smooth Pursuit ◽  
Clustering Algorithm ◽  
Critical Role ◽  
Image Motion ◽  
Frontal Eye Field ◽  
Smooth Pursuit Eye Movements ◽  
Pursuit Eye Movements ◽  
Eye Field ◽  
Eye Velocity

Neurons in the smooth eye movement subregion of the frontal eye field (FEFsem) are known to play an important role in voluntary smooth pursuit eye movements. Underlying this function are projections to parietal and prefrontal visual association areas and subcortical structures, all known to play vital but differing roles in the execution of smooth pursuit. Additionally, the FEFsem has been shown to carry a diverse array of signals (e.g., eye velocity, acceleration, gain control). We hypothesized that distinct subpopulations of FEFsem neurons subserve these diverse functions and projections, and that the relative weights of retinal and extraretinal signals could form the basis for categorization of units. To investigate this, we used a step-ramp tracking task with a target blink to determine the relative contributions of retinal and extraretinal signals in individual FEFsem neurons throughout pursuit. We found that the contributions of retinal and extraretinal signals to neuronal activity and behavior change throughout the time course of pursuit. A clustering algorithm revealed three distinct neuronal subpopulations: cluster 1 was defined by a higher sensitivity to eye velocity, acceleration, and retinal image motion; cluster 2 had greater activity during blinks; and cluster 3 had significantly greater eye position sensitivity. We also performed a comparison with a sample of medial superior temporal neurons to assess similarities and differences between the two areas. Our results indicate the utility of simple tests such as the target blink for parsing the complex and multifaceted roles of cortical areas in behavior. NEW & NOTEWORTHY The frontal eye field (FEF) is known to play a critical role in volitional smooth pursuit, carrying a variety of signals that are distributed throughout the brain. This study used a novel application of a target blink task during step ramp tracking to determine, in combination with a clustering algorithm, the relative contributions of retinal and extraretinal signals to FEF activity and the extent to which these contributions could form the basis for a categorization of neurons.

scholarly journals Bilateral Involvement of the Right Frontal Eye Field in Saccade Production

2010 ◽  
Vol 10 (7) ◽  
pp. 504-504
Author(s):  
W. Pack ◽  
T. Carney ◽  
S. Klein
Keyword(s):  
Frontal Eye Field ◽  
Bilateral Involvement ◽  
Eye Field ◽  
The Right
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