scholarly journals Cortical microcircuitry of gaze monitoring in supplementary eye field

2019 ◽  
Vol 19 (10) ◽  
pp. 306c
Author(s):  
Steven P Errington ◽  
Amirsaman Sajad ◽  
Jeffrey D Schall
1996 ◽  
Vol 75 (5) ◽  
pp. 2187-2191 ◽  
Author(s):  
H. Mushiake ◽  
N. Fujii ◽  
J. Tanji

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.


1987 ◽  
Vol 57 (1) ◽  
pp. 179-200 ◽  
Author(s):  
J. Schlag ◽  
M. Schlag-Rey

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.


2011 ◽  
Vol 11 (11) ◽  
pp. 529-529
Author(s):  
S. Heinen ◽  
S.-n. Yang ◽  
J. Ford

2007 ◽  
Vol 97 (5) ◽  
pp. 3554-3566 ◽  
Author(s):  
David E. Moorman ◽  
Carl R. Olson

Neurons in the macaque supplementary eye field (SEF) fire at different rates in conjunction with planning saccades in different directions. They also exhibit object-centered spatial selectivity, firing at different rates when the target of the saccade is at the left or right end of a horizontal bar. To compare the rate of incidence of the two kinds of signal, and to determine how they combine, we recorded from SEF neurons while monkeys performed a task in which the target (a dot or the left or right end of a horizontal bar) could appear in any visual field quadrant. During the period when the target was visible on the screen and the monkey was preparing to make a saccade, many neurons exhibited selectivity for saccade direction, firing at a rate determined by the direction of the impending saccade irrespective of whether the target was a dot or the end of a bar. On bar trials, many of the same neurons exhibited object-centered selectivity, firing more strongly when the target was at the preferred end of the bar regardless of saccade direction. The rate of incidence of object-centered selectivity (33%) was lower overall than that of saccade-direction selectivity (56%). Signals related to saccade direction and the object-centered location of the target tended to combine additively. The results suggest that the SEF is at a transitional stage between representing the object-centered command and specifying the parameters of the saccade.


2000 ◽  
Vol 83 (4) ◽  
pp. 2392-2411 ◽  
Author(s):  
Carl R. Olson ◽  
Léon Tremblay

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.


2004 ◽  
Vol 14 (11) ◽  
pp. R416-R418 ◽  
Author(s):  
R.H.S. Carpenter

2011 ◽  
Vol 105 (5) ◽  
pp. 2547-2559 ◽  
Author(s):  
Tamara K. Berdyyeva ◽  
Carl R. Olson

Neurons in several areas of the monkey frontal cortex exhibit rank selectivity, firing differentially as a function of the stage attained during the performance of a serial order task. The activity of these neurons is commonly thought to represent ordinal position within the trial. However, they might also be sensitive to factors correlated with ordinal position including time elapsed during the trial (which is greater for each successive stage) and the degree of anticipation of reward (which probably increases at each successive stage). To compare the influences of these factors, we monitored neuronal activity in the supplementary motor area (SMA), presupplementary motor area (pre-SMA), supplementary eye field (SEF), and dorsolateral prefrontal cortex during the performance of a serial order task (requiring a series of saccades in three specified directions), a variable reward task (in which a cue displayed early in the trial indicated whether the reward received at the end of the trial would be large or small), and a long delay task (in which the monkey had simply to maintain fixation during a period of time approximating the duration of an average trial in the serial order task). We found that rank signals were partially correlated with sensitivity to elapsed time and anticipated reward. The connection to elapsed time was strongest in the pre-SMA. The connection to anticipated reward was most pronounced in the SMA and SEF. However, critically, these factors could not fully explain rank selectivity in any of the areas tested.


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