Microstimulation of the Frontal Eye Field and Its Effects on Covert Spatial Attention

2004 ◽  
Vol 91 (1) ◽  
pp. 152-162 ◽  
Author(s):  
Tirin Moore ◽  
Mazyar Fallah
Keyword(s):  
Eye Movements ◽  
Spatial Attention ◽  
Saccadic Eye Movements ◽  
Visual Signals ◽  
Luminance Change ◽  
Target Event ◽  
Target Luminance ◽  
Electrical Microstimulation ◽  
Increased Sensitivity ◽  
Stimulation Of

Many studies have established that the strength of visual perception and the strength of visual representations within visual cortex vary according to the focus of covert spatial attention. While it is clear that attention can modulate visual signals, the source of this modulation remains unknown. We have examined the possibility that saccade related mechanisms provide a source of spatial attention by studying the effects of electrical microstimulation of the frontal eye fields (FEF) on spatial attention. Monkeys performed a task in which they had to detect luminance changes of a peripheral target while ignoring a flashing distracter. The target luminance change could be preceded by stimulation of the FEF at current levels below that which evoked saccadic eye movements. We found that when the target change was preceded by stimulation of FEF, the monkey could detect smaller changes in target luminance. The increased sensitivity to the target change only occurred when the target was placed in the part of the visual field represented by neurons at the stimulation site. The magnitude of improvement depended on the temporal asynchrony of the stimulation onset and the target event. No significant effect of stimulation was observed when long intervals (>300 ms) between stimulation and the target event were used, and the magnitude of the increased sensitivity decreased systematically with increasing asynchrony. At the shortest asynchrony, FEF stimulation temporally overlapped the target event and the magnitude of the improvement was comparable to that of removing the distracter from the task. These results demonstrate that transient, but potent improvements in the deployment of covert spatial attention can be obtained by microstimulation of FEF sites from which saccadic eye movements are also evoked.

Motor intention activity in the macaque's lateral intraparietal area. I. Dissociation of motor plan from sensory memory

1996 ◽  
Vol 76 (3) ◽  
pp. 1439-1456 ◽  
Author(s):  
P. Mazzoni ◽  
R. M. Bracewell ◽  
S. Barash ◽  
R. A. Andersen
Keyword(s):  
Eye Movements ◽  
Visual Stimulus ◽  
Visual Stimuli ◽  
Saccadic Eye Movements ◽  
Stimulus Location ◽  
Sensory Memory ◽  
Lateral Intraparietal Area ◽  
Preferred Direction ◽  
Motor Plan ◽  
Stimulation Of

1. The lateral intraparietal area (area LIP) of the monkey's posterior parietal cortex (PPC) contains neurons that are active during saccadic eye movements. These neurons' activity includes visual and saccade-related components. These responses are spatially tuned and the location of a neuron's visual receptive field (RF) relative to the fovea generally overlaps its preferred saccade amplitude and direction (i.e., its motor field, MF). When a delay is imposed between the presentation of a visual stimulus and a saccade made to its location (memory saccade task), many LIP neurons maintain elevated activity during the delay (memory activity, M), which appears to encode the metrics of the next intended saccadic eye movements. Recent studies have alternatively suggested that LIP neurons encode the locations of visual stimuli regardless of where the animal intends to look. We examined whether the M activity of LIP neurons specifically encodes movement intention or the locations of recent visual stimuli, or a combination of both. In the accompanying study, we investigated whether the intended-movement activity reflects changes in motor plan. 2. We trained monkeys (Macaca mulatta) to memorize the locations of two visual stimuli and plan a sequence of two saccades, one to each remembered target, as we recorded the activity of single LIP neurons. Two targets were flashed briefly while the monkey maintained fixation; after a delay the fixation point was extinguished, and the monkey made two saccades in sequence to each target's remembered location, in the order in which the targets were presented. This "delayed double saccade" (DDS) paradigm allowed us to dissociate the location of visual stimulation from the direction of the planned saccade and thus distinguish neuronal activity related to the target's location from activity related to the saccade plan. By imposing a delay, we eliminated the confounding effect of any phasic responses coincident with the appearance of the stimulus and with the saccade. 3. We arranged the two visual stimuli so that in one set of conditions at least the first one was in the neuron's visual RF, and thus the first saccade was in the neuron's motor field (MF). M activity should be high in these conditions according to both the sensory memory and motor plan hypotheses. In another set of conditions, the second stimulus appeared in the RF but the first one was presented outside the RF, instructing the monkey to plan the first saccade away from the neuron's MF. If the M activity encodes the motor plan, it should be low in these conditions, reflecting the plan for the first saccade (away from the MF). If it is a sensory trace of the stimulus' location, it should be high, reflecting stimulation of the RF by the second target. 4. We tested 49 LIP neurons (in 3 hemispheres of 2 monkeys) with M activity on the DDS task. Of these, 38 (77%) had M activity related to the next intended saccade. They were active in the delay period, as expected, if the first saccade was in their preferred direction. They were less active or silent if the next saccade was not in their preferred direction, even when the second stimulus appeared in their RF. 5. The M activity of 8 (16%) of the remaining neurons specifically encoded the location of the most recent visual stimulus. Their firing rate during the delay reflected stimulation of the RF independently of the saccade being planned. The remaining 3 neurons had M activity that did not consistently encode either the next saccade or the stimulus' location. 6. We also recorded the activity of a subset of neurons (n = 38) in a condition in which no stimulus appeared in a neuron's RF, but the second saccade was in the neuron's MF. In this case the majority of neurons tested (23/38, 60%) became active in the period between the first and second saccade, even if neither stimulus had appeared in their RF. Moreover, this activity appeared only after the first saccade had started in all but two of

scholarly journals Voluntary Spatial Attention has Different Effects on Voluntary and Reflexive Saccades

2003 ◽  
Vol 3 ◽  
pp. 881-902 ◽  
Author(s):  
Stephanie K. Seidlits ◽  
Tammie Reza ◽  
Kevin A. Briand ◽  
Anne B. Sereno
Keyword(s):  
Eye Movements ◽  
Spatial Attention ◽  
Saccadic Eye Movements ◽  
Fundamental Issue ◽  
Fixation Condition ◽  
The Subject ◽  
Symbolic Cues ◽  
The Relationship ◽  
Reflexive Saccades ◽  
Gap Paradigm

Although numerous studies have investigated the relationship between saccadic eye movements and spatial attention, one fundamental issue remains controversial. Some studies have suggested that spatial attention facilitates saccades, whereas others have claimed that eye movements are actually inhibited when spatial attention is engaged. However, these discrepancies may be because previous research has neglected to separate and specify the effects of attention for two distinct types of saccades, namely reflexive (stimulus-directed) and voluntary (antisaccades). The present study explored the effects of voluntary spatial attention on both voluntary and reflexive saccades. Results indicate that voluntary spatial attention has different effects on the two types of saccades. Antisaccades were always greatly facilitated following the engagement of spatial attention by symbolic cues (arrows) informing the subject where the upcoming saccade should be directed. Reflexive saccades showed little or no cueing effects and exhibited significant facilitation only when these cues were randomly intermixed with uncued trials. In addition, the present study tested the effects of fixation condition (gap, step, and overlap) on attentional modulation. Cueing effects did not vary due to fixation condition. Thus, voluntary spatial attention consistently showed different effects on voluntary and reflexive saccades, and there was no evidence in these studies that voluntary cues inhibit reflexive saccades, even in a gap paradigm.

Saccadic eye movements evoked by microstimulation of the fastigial nucleus of macaque monkeys

1988 ◽  
Vol 60 (3) ◽  
pp. 1036-1052 ◽  
Author(s):  
H. Noda ◽  
S. Murakami ◽  
J. Yamada ◽  
J. Tamada ◽  
Y. Tamaki ◽  
...  
Keyword(s):  
Eye Movements ◽  
White Matter ◽  
Purkinje Cells ◽  
Saccadic Eye Movements ◽  
The Other ◽  
Fastigial Nucleus ◽  
Threshold Region ◽  
Other Hand ◽  
Low Threshold ◽  
Stimulation Of

1. Systematic exploration throughout the deep cerebellar nuclei and white matter disclosed that the region from which saccadic eye movements (saccades) were evoked with weak currents (less than 10 microA) was confined to the fastigial nucleus and the adjacent white matter. 2. When an electrode for stimulation was advanced in the cerebellum, saccades were evoked in the direction of the stimulated side (ipsilateral saccades) as it entered the low-threshold region. In some tracks, particularly when the electrode was advanced in the medial portion of the fastigial nucleus, the direction of the evoked saccades changed from the ipsilateral to the contralateral. 3. The mappings with microstimulation disclosed that the ipsilateral saccades were elicited from a relatively wide region that included almost the full extent of the fastigial nucleus. The low-threshold region continued in the white matter caudally into vermal lobule VII and rostrally into the dorsal aspect of the brachium conjunctivum. On the other hand, the contralateral saccades were evoked from a relatively circumscribed region in the ventromedial portion of the fastigial nucleus. 4. The reversal in the direction of the horizontal component occurred always in a narrow zone in the core of the fastigial nucleus. The caudal part of this zone coincided with an ellipsoidal region where anterogradely labeled axons of the Purkinje cells terminated when HRP was injected into vermal lobule VII. 5. When bicuculline (0.2-1 microgram) was injected in the ellipsoidal region, the ipsilateral saccades evoked from the dorsocaudal aspect of the region were suppressed for several hours. On the other hand, the contralateral saccades evoked from the ventromedial portion of the fastigial nucleus were either unchanged or enhanced. 6. Because the ipsilateral saccades were suppressed by bicuculline, they were most probably evoked by stimulation of the presynaptic component of gamma-amino-butyric acid-(GABA) mediated synapses, namely the axons of Purkinje cells. 7. Because stimulation of the presynaptic component of the inhibitory synapses evoked ipsilateral saccades, activation of the postsynaptic component would evoke contralateral saccades. In fact, the distribution of the fastigial sites yielding contralateral saccades coincided with the course of axons of fastigial neurons arising in the ellipsoidal region. It is most likely, therefore, that the contralateral saccades were evoked by stimulation of fastigial neurons.(ABSTRACT TRUNCATED AT 400 WORDS)

Short Report: Scrutinization, Spatial Attention, and the Spatial Programming of Saccadic Eye Movements

1992 ◽  
Vol 45 (4) ◽  
pp. 633-647 ◽  
Author(s):  
John M. Findlay ◽  
Zoi Kapoula
Keyword(s):  
Eye Movements ◽  
Visual Attention ◽  
Spatial Attention ◽  
Visual Space ◽  
Saccadic Eye Movements ◽  
Short Report ◽  
Similar Material ◽  
Visual Tasks ◽  
Corrective Saccade ◽  
Spatial Programming

Results are presented from an experiment in which subjects’ eye movements were recorded while they carried out two visual tasks with similar material. One task was chosen to require close visual scrutiny; the second was less visually demanding. The oculomotor behaviour in the two tasks differed in three ways. (1) When scrutinizing, there was a reduction in the area of visual space over which stimulation influences saccadic eye movements. (2) When moving their eyes to targets requiring scrutiny, subjects were more likely to make a corrective saccade. (3) The duration of fixations on targets requiring scrutiny was increased. The results are discussed in relation to current theories of visual attention and the control of saccadic eye movements.

Saccadic eye movements evoked by electrical stimulation of the cat's visual cortex

1988 ◽  
Vol 1 (1) ◽  
pp. 135-143 ◽  
Author(s):  
James T. McIlwain
Keyword(s):  
Eye Movements ◽  
Striate Cortex ◽  
Saccadic Eye Movements ◽  
Normal Response ◽  
Visual Orienting ◽  
Cortex Area ◽  
Orienting Behavior ◽  
Alert Cats ◽  
Coil Method ◽  
Stimulation Of

AbstractEye movements were recorded with the scleral search coil method while striate cortex (area 17) was stimulated in alert cats with their heads fixed. Regardless of where stimulation was applied in the retinotopic map, eye position at the onset of stimulation strongly affected the amplitudes of evoked saccades, but had much less influence on their directions. Application of long stimulus trains evoked repeated saccades at all sites tested. Highly convergent or goal-directed saccades were not observed. Cortically evoked saccades appeared to habituate with repeated stimulation and had higher thresholds and longer latencies that those reported for saccades evoked from the superior colliculus. The directions of cortically evoked saccades generally agreed with those predicted from the retinotopic coordinates of the stimulus sites, but saccade amplitudes were usually lower than expected. It is suggested that these findings are consistent with certain characteristics of eye-head coordination in the cat's normal visual orienting behavior. The results are difficult to reconcile with the hypothesis that goal-directed saccades are a normal response to targets outside the cat's oculomotor range.

scholarly journals Phosphene Induction and the Generation of Saccadic Eye Movements by Striate Cortex

2005 ◽  
Vol 93 (1) ◽  
pp. 1-19 ◽  
Author(s):  
E. J. Tehovnik ◽  
W. M. Slocum ◽  
C. E. Carvey ◽  
P. H. Schiller
Keyword(s):  
Electrical Stimulation ◽  
Eye Movements ◽  
Striate Cortex ◽  
Human Subjects ◽  
Saccadic Eye Movements ◽  
Visual Prosthesis ◽  
Prosthetic Device ◽  
Electrical Microstimulation ◽  
Stimulation Parameters ◽  
Cortex Area

The purpose of this review is to critically examine phosphene induction and saccadic eye movement generation by electrical microstimulation of striate cortex (area V1) in humans and monkeys. The following issues are addressed: 1) Properties of electrical stimulation as they pertain to the activation of V1 elements; 2) the induction of phosphenes in sighted and blind human subjects elicited by electrical stimulation using various stimulation parameters and electrode types; 3) the induction of phosphenes with electrical microstimulation of V1 in monkeys; 4) the generation of saccadic eye movements with electrical microstimulation of V1 in monkeys; and 5) the tasks involved for the development of a cortical visual prosthesis for the blind. In this review it is concluded that electrical microstimulation of area V1 in trained monkeys can be used to accelerate the development of an effective prosthetic device for the blind.

scholarly journals The eye that binds: Feature integration is not disrupted by saccadic eye movements

2019 ◽  
Vol 82 (2) ◽  
pp. 533-549 ◽  
Author(s):  
Josephine Reuther ◽  
Ramakrishna Chakravarthi ◽  
Amelia R. Hunt
Keyword(s):  
Eye Movements ◽  
Spatial Attention ◽  
Saccadic Eye Movements ◽  
Stimulus Presentation ◽  
Feature Integration ◽  
Integration Theory ◽  
Conjunction Errors ◽  
Retinal Motion ◽  
Retinotopic Maps ◽  
Feature Integration Theory

AbstractFeature integration theory proposes that visual features, such as shape and color, can only be combined into a unified object when spatial attention is directed to their location in retinotopic maps. Eye movements cause dramatic changes on our retinae, and are associated with obligatory shifts in spatial attention. In two experiments, we measured the prevalence of conjunction errors (that is, reporting an object as having an attribute that belonged to another object), for brief stimulus presentation before, during, and after a saccade. Planning and executing a saccade did not itself disrupt feature integration. Motion did disrupt feature integration, leading to an increase in conjunction errors. However, retinal motion of an equal extent but caused by saccadic eye movements is spared this disruption, and showed similar rates of conjunction errors as a condition with static stimuli presented to a static eye. The results suggest that extra-retinal signals are able to compensate for the motion caused by saccadic eye movements, thereby preserving the integrity of objects across saccades and preventing their features from mixing or mis-binding.

Some saccadic eye movements can be delayed by transcranial magnetic stimulation of the cerebral cortex in man

Brain ◽  
1993 ◽  
Vol 116 (2) ◽  
pp. 355-367 ◽  
Author(s):  
A. Priori ◽  
L. Bertolasi ◽  
J. C. Rothwell ◽  
B. L. Day ◽  
C. D. Marsden
Keyword(s):  
Cerebral Cortex ◽  
Eye Movements ◽  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Saccadic Eye Movements ◽  
Stimulation Of

scholarly journals Motor action of the frontal eye field on the eyes and neck in the monkey

2018 ◽  
Vol 119 (6) ◽  
pp. 2082-2090
Author(s):  
Yoshiko Izawa ◽  
Hisao Suzuki
Keyword(s):  
Eye Movements ◽  
Saccadic Eye Movements ◽  
Measuring System ◽  
Frontal Eye Field ◽  
Gaze Shift ◽  
Restrained Condition ◽  
Eye Field ◽  
Slow Eye Movements ◽  
Motor Actions ◽  
Stimulation Of

Focal stimulation in the frontal eye field (FEF) evoked eye movements that were often accompanied by neck movements. Experiments were performed with concurrent recording of both movements in trained monkeys. We recorded neck forces under a head-restrained condition with a force-measuring system. With the system, we measured forces along the x-, y-, and z-axes and torque about the z-axis. Torque about the z-axis that represented yaw rotation of the head was significantly affected by stimulation. We found that stimulation generated two types of motor actions of the eyes and neck. In the first type, contraversive neck forces were evoked by stimulation of the medial part of the FEF, where contraversive saccadic eye movements with large amplitudes were evoked. When the stimulus intensity was increased, saccades were evoked in an all-or-none manner, whereas the amplitude of neck forces increased gradually. In the second type, contraversive neck forces were evoked by stimulation of the medial and caudal part of the FEF, where ipsiversive slow eye movements were evoked. The depth profiles of amplitudes of neck forces were almost parallel to those of eye movements in individual stimulation tracks. The present results suggest that the FEF is involved in the control of motor actions of the neck as well as the eyes. The FEF area associated with contraversive saccades and contraversive neck movements may contribute to a gaze shift process, whereas that associated with ipsiversive slow eye movements and contraversive neck movements may contribute to a visual stabilization process. NEW & NOTEWORTHY Focal stimulation in the frontal eye field (FEF) evoked eye and neck movements. We recorded neck forces under a head-restrained condition with a force-measuring system. Taking advantage of this approach, we could analyze slow eye movements that were dissociated from the vestibuloocular reflex. We found ipsiversive slow eye movements in combination with contraversive neck forces, suggesting that the FEF may be a source of a corollary discharge signal for compensatory eye movements during voluntary neck movements.

Stimulation of the caudate nucleus induces contraversive saccadic eye movements as well as head turning in the cat

1991 ◽  
Vol 12 (1) ◽  
pp. 287-292 ◽  
Author(s):  
Toshihiro Kitama ◽  
Tadao Ohno ◽  
Maki Tanaka ◽  
Hiroshi Tsubokawa ◽  
Kaoru Yoshida
Keyword(s):  
Eye Movements ◽  
Caudate Nucleus ◽  
Saccadic Eye Movements ◽  
Head Turning ◽  
Stimulation Of
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