Effect of Reversible Inactivation of Macaque Lateral Intraparietal Area on Visual and Memory Saccades

1999 ◽  
Vol 81 (4) ◽  
pp. 1827-1838 ◽  
Author(s):  
Chiang-Shan Ray Li ◽  
Pietro Mazzoni ◽  
Richard A. Andersen
Keyword(s):  
Eye Movements ◽  
Sensory Information ◽  
Saccadic Eye Movements ◽  
Direct Role ◽  
Unit Recording ◽  
Reversible Inactivation ◽  
Lateral Intraparietal Area ◽  
Upper Visual Field ◽  
Eye Field ◽  
Parietal Eye

Effect of reversible inactivation of macaque lateral intraparietal area on visual and memory saccades. Previous studies from our laboratory identified a parietal eye field in the primate lateral intraparietal sulcus, the lateral intraparietal area (area LIP). Here we further explore the role of area LIP in processing saccadic eye movements by observing the effects of reversible inactivation of this area. One to 2 μl of muscimol (8 mg/ml) were injected at locations where saccade-related activities were recorded for each lesion experiment. After the muscimol injection we observed in two macaque monkeys consistent effects on both the metrics and dynamics of saccadic eye movements at many injection sites. These effects usually took place within 10–30 min and disappeared after 5–6 h in most cases and certainly when tested the next day. After muscimol injection memory saccades directed toward the contralesional and upper space became hypometric, and in one monkey those to the ipsilesional space were slightly but significantly hypermetric. In some cases, the scatter of the end points of memory saccades was also increased. On the other hand, the metrics of visual saccades remained relatively intact. Latency for both visual and memory saccades toward the contralesional space was increased and in many cases displayed a higher variance after muscimol lesion. At many injection sites we also observed an increase of latency for visual and memory saccades toward the upper space. The peak velocities for memory saccades toward the contralesional space were decreased after muscimol injection. The peak velocities of visual saccades were not significantly different from those of the controls. The duration of saccadic eye movements either to the ipsilesional or contralesional space remained relatively the same for both visual and memory saccades. Overall these results demonstrated that we were able to selectively inactivate area LIP and observe effects on saccadic eye movements. Together with our previous recording studies these results futher support the view that area LIP plays a direct role in processing incoming sensory information to program saccadic eye movements. The results are consistent with our unit recording data and microstimulation studies, which suggest that area LIP represents contralateral space and also has a bias for the upper visual field.

Functional Anatomy of Pursuit Eye Movements in Humans as Revealed by fMRI

1999 ◽  
Vol 82 (1) ◽  
pp. 463-471 ◽  
Author(s):  
Laurent Petit ◽  
James V. Haxby
Keyword(s):  
Eye Movements ◽  
Temporal Cortex ◽  
Functional Anatomy ◽  
Saccadic Eye Movements ◽  
Frontal Eye Field ◽  
Pursuit Eye Movements ◽  
Magnetic Imaging ◽  
Supplementary Eye Field ◽  
Eye Field ◽  
Parietal Eye

We have investigated the functional anatomy of pursuit eye movements in humans with functional magnetic imaging. The performance of pursuit eye movements induced activations in the cortical eye fields also activated during the execution of visually guided saccadic eye movements, namely in the precentral cortex [frontal eye field (FEF)], the medial superior frontal cortex (supplementary eye field), the intraparietal cortex (parietal eye field), and the precuneus, and at the junction of occipital and temporal cortex (MT/MST) cortex. Pursuit-related areas could be distinguished from saccade-related areas both in terms of spatial extent and location. Pursuit-related areas were smaller than their saccade-related counterparts, three of eight significantly so. The pursuit-related FEF was usually inferior to saccade-related FEF. Other pursuit-related areas were consistently posterior to their saccade-related counterparts. The current findings provide the first functional imaging evidence for a distinction between two parallel cortical systems that subserve pursuit and saccadic eye movements in humans.

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

Characteristics of antidromically identified oculomotor internuclear neurons during vergence and versional eye movements

1994 ◽  
Vol 71 (3) ◽  
pp. 1111-1127 ◽  
Author(s):  
R. A. Clendaniel ◽  
L. E. Mays
Keyword(s):  
Eye Movements ◽  
Medial Rectus ◽  
Oculomotor Nucleus ◽  
Abducens Nucleus ◽  
Unit Recording ◽  
Antidromic Activation ◽  
Reversible Inactivation ◽  
Lidocaine Injection ◽  
Lidocaine Hcl ◽  
Tonic Pattern

1. Previous studies have shown that midbrain near response cells that increase their activity during convergent eye movements project to medial rectus motoneurons, which also increase their activity during convergence. Most neurons in the abducens nucleus decrease their firing rate during convergence, and the source of this vergence signal is unknown. Oculomotor internuclear neurons (OINs) in monkeys project primarily from the medial rectus subdivisions of the oculomotor nucleus to the contralateral abducens nucleus, although there is a smaller ipsilateral projection as well. Because of these anatomic connections, it has been suggested that the OIN input may be responsible for the vergence signal seen on abducens neurons. The behavior of the OINs during eye movements and their synaptic drive are not known. Thus the goal of this study is to determine the behavior of these neurons during conjugate and disjunctive eye movements and to determine if these neurons have an excitatory or inhibitory drive on the abducens neurons. 2. Single-unit recording studies in alert rhesus monkeys were used to characterize the behavior of OINs. Eighteen OINs were identified by antidromic activation and collision testing. The recorded OINs displayed a burst-tonic pattern of activity during adducting saccades, and the majority of these cells displayed an increase in tonic activity with convergent eye movements. 3. Identified OINs were compared with a large sample of non-activated and untested horizontal burst-tonic cells in the medial rectus subdivisions of the oculomotor nucleus. The results indicate that the OINs behave similarly to medial rectus motoneurons during vergence and versional eye movements. None of the OINs displayed vertical eye position sensitivity. 4. Microstimulation of the oculomotor nucleus where both the OINs and medial rectus motoneurons were located resulted in a large adducting twitch of the ipsilateral eye and a smaller abducting twitch of the contralateral eye. The latter effect was presumed to be the result of OIN innervation of the contralateral abducens nucleus. This result suggests that the crossed OIN pathway is predominately, if not entirely, excitatory. 5. Injection of 10% lidocaine HCl into the medial rectus subdivision of the oculomotor nucleus caused a reversible inactivation of the medial rectus motoneurons and OINs. As expected, the inactivation of medial rectus motoneurons resulted in an exophoria and weakness of adduction for the eye ipsilateral to the lidocaine injection. In addition, the lidocaine injection resulted in hypometric and slowed abducting saccades in the eye contralateral to the injection site. This result also suggest that the crossed OIN pathway is excitatory.(ABSTRACT TRUNCATED AT 400 WORDS)

Suppression of Task-Related Saccades by Electrical Stimulation in the Primate's Frontal Eye Field

1997 ◽  
Vol 77 (5) ◽  
pp. 2252-2267 ◽  
Author(s):  
Douglas D. Burman ◽  
Charles J. Bruce
Keyword(s):  
Electrical Stimulation ◽  
Eye Movements ◽  
Frontal Lobe ◽  
Premotor Cortex ◽  
Saccadic Eye Movements ◽  
Association Cortex ◽  
Frontal Eye Field ◽  
Visually Guided ◽  
Low Intensity ◽  
Eye Field

Burman, Douglas D. and Charles J. Bruce. Suppression of task-related saccades by electrical stimulation in the primate's frontal eye field. J. Neurophysiol. 77: 2252–2267, 1997. Patients with frontal lobe damage have difficulty suppressing reflexive saccades to salient visual stimuli, indicating that frontal lobe neocortex helps to suppress saccades as well as to produce them. In the present study, a role for the frontal eye field (FEF) in suppressing saccades was demonstrated in macaque monkeys by application of intracortical microstimulation during the performance of a visually guided saccade task, a memory prosaccade task, and a memory antisaccade task. A train of low-intensity (20–50 μA) electrical pulses was applied simultaneously with the disappearance of a central fixation target, which was always the cue to initiate a saccade. Trials with and without stimulation were compared, and significantly longer saccade latencies on stimulation trials were considered evidence of suppression. Low-intensity stimulation suppressed task-related saccades at 30 of 77 sites tested. In many cases saccades were suppressed throughout the microstimulation period (usually 450 ms) and then executed shortly after the train ended. Memory-guided saccades were most dramatically suppressed and were often rendered hypometric, whereas visually guided saccades were less severely suppressed by stimulation. At 18 FEF sites, the suppression of saccades was the only observable effect of electrical stimulation. Contraversive saccades were usually more strongly suppressed than ipsiversive ones, and cells recorded at such purely suppressive sites commonly had either foveal receptive fields or postsaccadic responses. At 12 other FEF sites at which saccadic eye movements were elicited at low thresholds, task-related saccades whose vectors differed from that of the electrically elicited saccade were suppressed by electrical stimulation. Such suppression at saccade sites was observed even with currents below the threshold for eliciting saccades. Pure suppression sites tended to be located near or in the fundus, deeper in the anterior bank of the arcuate than elicited saccade sites. Stimulation in the prefrontal association cortex anterior to FEF did not suppress saccades, nor did stimulation in premotor cortex posterior to FEF. These findings indicate that the primate FEF can help orchestrate saccadic eye movements by suppressing inappropriate saccade vectors as well as by selecting, specifying, and triggering appropriate saccades. We hypothesize that saccades could be suppressed both through local FEF interactions and through FEF projections to subcortical regions involved in maintaining fixation.

scholarly journals Role of the human supplementary eye field in the control of saccadic eye movements

2007 ◽  
Vol 45 (5) ◽  
pp. 997-1008 ◽  
Author(s):  
Andrew Parton ◽  
Parashkev Nachev ◽  
Timothy L. Hodgson ◽  
Dominic Mort ◽  
David Thomas ◽  
...  
Keyword(s):  
Eye Movements ◽  
Saccadic Eye Movements ◽  
Supplementary Eye Field ◽  
Eye Field

Muscimol-Induced Inactivation of Monkey Frontal Eye Field: Effects on Visually and Memory-Guided Saccades

1999 ◽  
Vol 81 (5) ◽  
pp. 2191-2214 ◽  
Author(s):  
Elisa C. Dias ◽  
Mark A. Segraves
Keyword(s):  
Eye Movements ◽  
Target Location ◽  
Memory Task ◽  
Saccadic Eye Movements ◽  
Spatial Location ◽  
Frontal Eye Field ◽  
Visually Guided ◽  
Field Effects ◽  
Progressive Loss ◽  
Eye Field

Muscimol-induced inactivation of the monkey frontal eye field: effects on visually and memory-guided saccades. Although neurophysiological, anatomic, and imaging evidence suggest that the frontal eye field (FEF) participates in the generation of eye movements, chronic lesions of the FEF in both humans and monkeys appear to cause only minor deficits in visually guided saccade generation. Stronger effects are observed when subjects are tested in tasks with more cognitive requirements. We tested oculomotor function after acutely inactivating regions of the FEF to minimize the effects of plasticity and reallocation of function after the loss of the FEF and gain more insight into the FEF contribution to the guidance of eye movements in the intact brain. Inactivation was induced by microinjecting muscimol directly into physiologically defined sites in the FEF of three monkeys. FEF inactivation severely impaired the monkeys’ performance of both visually guided and memory-guided saccades. The monkeys initiated fewer saccades to the retinotopic representation of the inactivated FEF site than to any other location in the visual field. The saccades that were initiated had longer latencies, slower velocities, and larger targeting errors than controls. These effects were present both for visually guided and for memory-guided saccades, although the memory-guided saccades were more disrupted. Initially, the effects were restricted spatially, concentrating around the retinotopic representation at the center of the inactivated site, but, during the course of several hours, these effects spread to flanking representations. Predictability of target location and motivation of the monkey also affected saccadic performance. For memory-guided saccades, increases in the time during which the monkey had to remember the spatial location of a target resulted in further decreases in the accuracy of the saccades and in smaller peak velocities, suggesting a progressive loss of the capacity to maintain a representation of target location in relation to the fovea after FEF inactivation. In addition, the monkeys frequently made premature saccades to targets in the hemifield ipsilateral to the injection site when performing the memory task, indicating a deficit in the control of fixation that could be a consequence of an imbalance between ipsilateral and contralateral FEF activity after the injection. There was also a progressive loss of fixation accuracy, and the monkeys tended to restrict spontaneous visual scanning to the ipsilateral hemifield. These results emphasize the strong role of the FEF in the intact monkey in the generation of all voluntary saccadic eye movements, as well as in the control of fixation.

Deficits in eye movements following frontal eye-field and superior colliculus ablations

1980 ◽  
Vol 44 (6) ◽  
pp. 1175-1189 ◽  
Author(s):  
P. H. Schiller ◽  
S. D. True ◽  
J. L. Conway
Keyword(s):  
Eye Movements ◽  
Visual Field ◽  
Superior Colliculus ◽  
Saccadic Eye Movements ◽  
The Other ◽  
Frontal Eye Field ◽  
Saccade Velocity ◽  
Eye Field ◽  
Parallel Channels ◽  
Coil Method

1. This study investigated the effects of frontal eye-field and superior colliculus ablations on fixation patterns and saccadic eye movements. Monkeys were trained to pick apple pieces out of a multiple-slotted apple board while their heads were fixed. Eye movement records were obtained using predominantly the implanted search-coil method. 2. Both unilateral and bilateral frontal eye-field lesions produced only temporary deficits in eye movements. Following surgery monkeys tended to neglect the contralateral peripheral visual field and made fewer saccades to peripheral targets. Recovery was virtually completed in 2-4 wk. 3. Superior colliculus ablation reduced fixation accuracy, saccade frequency, and saccade velocity. These deficits showed little recovery with time. 4. Paired frontal eye-field and superior colliculus lesions produced dramatic deficits in visually triggered eye movements. Animals could no longer fixate their eyes on visual targets with any degree of accuracy. The range of eye movements was greatly reduced, as was the frequency and velocity of saccades. These deficits showed little recovery with time. 5. These results suggest that visually triggered saccadic eye movements are controlled by two parallel channels, one involving the superior colliculus and the other the frontal eye field.

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.

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