scholarly journals Covert Reorienting and Inhibition of Return: An Event-Related fMRI Study

2002 ◽  
Vol 14 (2) ◽  
pp. 127-144 ◽  
Author(s):  
Jöran Lepsien ◽  
Stefan Pollmann
Keyword(s):  
Inhibition Of Return ◽  
Response Times ◽  
Stimulus Onset ◽  
Frontal Eye Field ◽  
Functional Neuroanatomy ◽  
Attentional Processes ◽  
Supplementary Eye Field ◽  
Fmri Study ◽  
Eye Field ◽  
The Right

Using event-related fMRI, we analyzed the functional neuroanatomy of covert reorienting and inhibition of return (IOR). Covert reorienting to a target appearing within 250 msec after an invalid contralateral location cue elicited increased activation in the left fronto-polar cortex (LFPC), right anterior and left posterior middle frontal gyrus, and right cerebellum, areas that have previously been associated with attentional processes, specifically attentional change. In contrast, IOR, which leads to prolonged response times to targets that appear at the cued location at a stimulus-onset-asynchrony (SOA)>250 msec, was accompanied by increased activation in brain areas involved in oculomotor programming, such as the right medial frontal gyrus (supplementary eye field; SEF) and the right inferior precentral sulcus (frontal eye field; FEF), supporting the oculomotor bias theory of IOR. Pre-SEF and pre-FEF areas were involved both in covert reorienting and IOR. The supramarginal gyri were bilaterally involved in IOR, with the right supramarginal gyrus additionally involved in covert reorienting.

An Event-related fMRI Study of Exogenous Facilitation and Inhibition of Return in the Auditory Modality

2007 ◽  
Vol 19 (3) ◽  
pp. 455-467 ◽  
Author(s):  
Andrew R. Mayer ◽  
Deborah L. Harrington ◽  
Julia Stephen ◽  
John C. Adair ◽  
Roland R. Lee
Keyword(s):  
Inhibition Of Return ◽  
Functional Results ◽  
Stimulus Onset ◽  
Auditory Modality ◽  
Auditory Cues ◽  
Fmri Study ◽  
Sensory Modalities ◽  
Postcentral Gyrus ◽  
The Right ◽  
Onset Asynchrony

The orienting of attention to different locations in space is fundamental to most organisms and occurs in all sensory modalities. Orienting has been extensively studied in vision, but to date, few studies have investigated neuronal networks underlying automatic orienting of attention and inhibition of return to auditory signals. In the current experiment, functional magnetic resonance imaging and behavioral data were collected while healthy volunteers performed an auditory orienting task in which a monaurally presented tone pip (cue) correctly or incorrectly cued the location of a target tone pip. The stimulus onset asynchrony (SOA) between the cue and target was 100 or 800 msec. Behavioral results were consistent with previous studies showing that valid auditory cues produced facilitation at the short SOA and inhibition of return at the long SOA. Functional results indicated that the reorienting of attention (100 msec SOA) and inhibition of return (800 msec SOA) were mediated by both common and distinct neuronal structures. Both attention mechanisms commonly activated a network consisting of fronto-oculomotor areas, the left postcentral gyrus, right premotor area, and bilateral tonsil of the cerebellum. Several distinct areas of frontal and parietal activation were identified for the reorienting condition, whereas the right inferior parietal lobule was the only structure uniquely associated with inhibition of return.

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.

Visually guided saccade versus eye-hand reach: contrasting neuronal activity in the cortical supplementary and frontal eye fields

1996 ◽  
Vol 75 (5) ◽  
pp. 2187-2191 ◽  
Author(s):  
H. Mushiake ◽  
N. Fujii ◽  
J. Tanji
Keyword(s):  
Eye Movement ◽  
Neuronal Activity ◽  
Motor Task ◽  
Oculomotor Control ◽  
Frontal Eye Field ◽  
Frontal Eye Fields ◽  
Saccadic Eye Movement ◽  
Visually Guided ◽  
Supplementary Eye Field ◽  
Eye Field

1. We studied neuronal activity in the supplementary eye field (SEF) and frontal eye field (FEF) of a monkey during performance of a conditional motor task that required capturing of a target either with a saccadic eye movement (the saccade-only condition) or with an eye-hand reach (the saccade-and-reach condition), according to visual instructions. 2. Among 106 SEF neurons that showed presaccadic activity, more than one-half of them (54%) were active preferentially under the saccade-only condition (n = 12) or under the saccade-and-reach condition (n = 45), while the remaining 49 neurons were equally active in both conditions. 3. By contrast, most (97%) of the 109 neurons in the FEF exhibited approximately equal activity in relation to saccades under the two conditions. 4. The present results suggest the possibility that SEF neurons, at least in part, are involved in signaling whether the motor task is oculomotor or combined eye-arm movements, whereas FEF neurons are mostly related to oculomotor control.

Foveal Attention Modulates Responses to Peripheral Stimuli

2000 ◽  
Vol 83 (4) ◽  
pp. 2443-2452 ◽  
Author(s):  
Simo Vanni ◽  
Kimmo Uutela
Keyword(s):  
Visual Field ◽  
Target Location ◽  
Peripheral Vision ◽  
Human Subjects ◽  
Stimulus Onset ◽  
Visual Object ◽  
Frontal Eye Field ◽  
L1 Norm ◽  
Luminance Stimulus ◽  
The Right

When attending to a visual object, peripheral stimuli must be monitored for appropriate redirection of attention and gaze. Earlier work has revealed precentral and posterior parietal activation when attention has been directed to peripheral vision. We wanted to find out whether similar cortical areas are active when stimuli are presented in nonattended regions of the visual field. The timing and distribution of neuromagnetic responses to a peripheral luminance stimulus were studied in human subjects with and without attention to fixation. Cortical current distribution was analyzed with a minimum L1-norm estimate. Attention enhanced responses 100–160 ms after the stimulus onset in the right precentral cortex, close to the known location of the right frontal eye field. In subjects whose right precentral region was not distinctly active before 160 ms, focused attention commonly enhanced right inferior parietal responses between 180 and 240 ms, whereas in the subjects with clear earlier precentral response no parietal enhancement was detected. In control studies both attended and nonattended stimuli in the peripheral visual field evoked the right precentral response, whereas during auditory attention the visual stimuli failed to evoke such response. These results show that during focused visual attention the right precentral cortex is sensitive to stimuli in all parts of the visual field. A rapid response suggests bypassing of elaborate analysis of stimulus features, possibly to encode target location for a saccade or redirection of attention. In addition, load for frontal and parietal nodi of the attentional network seem to vary between individuals.

Evidence for a supplementary eye field

1987 ◽  
Vol 57 (1) ◽  
pp. 179-200 ◽  
Author(s):  
J. Schlag ◽  
M. Schlag-Rey
Keyword(s):  
Unit Activity ◽  
Cortical Neurons ◽  
Cortical Area ◽  
Head Movements ◽  
Frontal Eye Field ◽  
Unit Recording ◽  
Electrical Microstimulation ◽  
Preferred Direction ◽  
Supplementary Eye Field ◽  
Eye Field

Electrical microstimulation and unit recording were performed in dorsomedial frontal cortex of four alert monkeys to identify an oculomotor area whose existence had been postulated rostral to the supplementary motor area. Contraversive saccades were evoked from 129 sites by stimulation. Threshold currents were lower than 20 microA in half the tests. Response latencies were usually longer than 50 ms (minimum: 30 ms). Eye movements were occasionally accompanied by blinks, ear, or neck movements. The cortical area yielding these movements was at the superior edge of the frontal lobe just rostral to the region from which limb movements could be elicited. Depending on the site of stimulation, saccades varied between two extremes: from having rather uniform direction and size, to converging toward a goal defined in space. The transition between these extremes was gradual with no evidence that these two types were fundamentally different. From surface to depth of cortex, direction and amplitude of evoked saccades were similar or changed progressively. No clear systematization was found depending on location along rostrocaudal or mediolateral axes of the cortex. The dorsomedial oculomotor area mapped was approximately 7 mm long and 6 mm wide. Combined eye and head movements were elicited from one of ten sites stimulated when the head was unrestrained. In the other nine cases, saccades were not accompanied by head rotation, even when higher currents or longer stimulus trains were applied. Presaccadic unit activity was recorded from 62 cells. Each of these cells had a preferred direction that corresponded to the direction of the movement evoked by local microstimulation. Presaccadic activity occurred with self-initiated as well as visually triggered saccades. It often led self-initiated saccades by more than 300 ms. Recordings made with the head free showed that the firing could not be interpreted as due to attempted head movements. Many dorsomedial cortical neurons responded to photic stimuli, either phasically or tonically. Sustained responses (activation or inhibition) were observed during target fixation. Twenty-one presaccadic units showed tonic changes of activity with fixation. Justification is given for considering the cortical area studied as a supplementary eye field. It shares many common properties with the arcuate frontal eye field. Differences noted in this study include: longer latency of response to electrical stimulation, possibility to evoke saccades converging apparently toward a goal, and long-lead unit activity with spontaneous saccades.

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.

Macaque Supplementary Eye Field Neurons Encode Object-Centered Locations Relative to Both Continuous and Discontinuous Objects

2000 ◽  
Vol 83 (4) ◽  
pp. 2392-2411 ◽  
Author(s):  
Carl R. Olson ◽  
Léon Tremblay
Keyword(s):  
Eye Movements ◽  
Macaque Monkey ◽  
Direction Selectivity ◽  
Reference Image ◽  
Minor Effect ◽  
Supplementary Eye Field ◽  
Level Of Activity ◽  
Eye Field ◽  
The Right ◽  
Horizontal Array

Many neurons in the supplementary eye field (SEF) of the macaque monkey fire at different rates before eye movements to the right or the left end of a horizontal bar regardless of the bar's location in the visual field. We refer to such neurons as carrying object-centered directional signals. The aim of the present study was to throw light on the nature of object-centered direction selectivity by determining whether it depends on the reference image's physical continuity. To address this issue, we recorded from 143 neurons in two monkeys. All of these neurons were located in a region coincident with the SEF as mapped out in previous electrical stimulation studies and many exhibited task-related activity in a standard saccade task. In each neuron, we compared neuronal activity across trials in which the monkey made eye movements to the right or left end of a reference image. On interleaved trials, the reference image might be either a horizontal bar or a pair of discrete dots in a horizontal array. The dominant effect revealed by this experiment was that neurons selectively active before eye movements to the right (or left) end of a bar were also selectively active before eye movements to the right (or left) dot in a horizontal array. An additional minor effect, present in around a quarter of the sample, took the form of a difference in firing rate between bar and dot trials, with the greater level of activity most commonly associated with dot trials. These phenomena could not be accounted for by minor intertrial differences in the physical directions of eye movements. In summary, SEF neurons carry object-centered signals and carry these signals regardless of whether the reference image is physically continuous or disjunct.

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 Role of Supplementary Eye Field in Saccade Initiation: Executive, Not Direct, Control

2010 ◽  
Vol 103 (2) ◽  
pp. 801-816 ◽  
Author(s):  
Veit Stuphorn ◽  
Joshua W. Brown ◽  
Jeffrey D. Schall
Keyword(s):  
Discharge Rate ◽  
Stop Signal ◽  
Stop Signal Task ◽  
Frontal Eye Field ◽  
Signal Trial ◽  
Visually Guided ◽  
Supplementary Eye Field ◽  
Task Requirements ◽  
Gaze Holding ◽  
Eye Field

The goal of this study was to determine whether the activity of neurons in the supplementary eye field (SEF) is sufficient to control saccade initiation in macaque monkeys performing a saccade countermanding (stop signal) task. As previously observed, many neurons in the SEF increase the discharge rate before saccade initiation. However, when saccades are canceled in response to a stop signal, effectively no neurons with presaccadic activity display discharge rate modulation early enough to contribute to saccade cancellation. Moreover, SEF neurons do not exhibit a specific threshold discharge rate that could trigger saccade initiation. Yet, we observed more subtle relations between SEF activation and saccade production. The activity of numerous SEF neurons was correlated with response time and varied with sequential adjustments in response latency. Trials in which monkeys canceled or produced a saccade in a stop signal trial were distinguished by a modest difference in discharge rate of these SEF neurons before stop signal or target presentation. These findings indicate that neurons in the SEF, in contrast to counterparts in the frontal eye field and superior colliculus, do not contribute directly and immediately to the initiation of visually guided saccades. However the SEF may proactively regulate saccade production by biasing the balance between gaze-holding and gaze-shifting based on prior performance and anticipated task requirements.

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