scholarly journals Interaction Between Smooth Anticipation and Saccades During Ocular Orientation in Darkness

2003 ◽  
Vol 89 (3) ◽  
pp. 1423-1433 ◽  
Author(s):  
Gunnar Blohm ◽  
Marcus Missal ◽  
Philippe Lefèvre
Keyword(s):  
Eye Movements ◽  
Smooth Pursuit ◽  
Time Course ◽  
Motor Command ◽  
Visual Axis ◽  
Anticipatory Eye Movements ◽  
Saccade Programming ◽  
The Moment ◽  
Retinal Information ◽  
Movement Integration

A saccade triggered during sustained smooth pursuit is programmed using retinal information about the relative position and velocity of the target with respect to the eye. Thus the smooth pursuit and saccadic systems are coordinated by using common retinal inputs. Yet, in the absence of retinal information about the relative motion of the eye with respect to the target, the question arises whether the smooth and saccadic systems are still able to be coordinated possibly by using extraretinal information to account for the saccadic and smooth eye movements. To address this question, we flashed a target during smooth anticipatory eye movements in darkness, and the subjects were asked to orient their visual axis to the remembered location of the flash. We observed multiple orientation saccades (typically 2–3) toward the memorized location of the flash. The first orienting saccade was programmed using only the position error at the moment of the flash, and the smooth eye movement was ignored. However, subsequent saccades executed in darkness compensated gradually for the smooth eye displacement (mean compensation ≅ 70%). This behavior revealed a 400-ms delay in the time course of orientation for the compensation of the ongoing smooth eye displacement. We conclude that extraretinal information about the smooth motor command is available to the saccadic system in the absence of visual input. There is a 400-ms delay for smooth movement integration, saccade programming and execution.

Dissociation of Visual Discrimination From Saccade Programming in Macaque Frontal Eye Field

1997 ◽  
Vol 77 (2) ◽  
pp. 1046-1050 ◽  
Author(s):  
Kirk G. Thompson ◽  
Narcisse P. Bichot ◽  
Jeffrey D. Schall
Keyword(s):  
Visual Search ◽  
Eye Movements ◽  
Visual Stimulus ◽  
Visual Discrimination ◽  
Time Course ◽  
Selection Process ◽  
Frontal Eye Field ◽  
Visual Responses ◽  
Eye Field ◽  
Saccade Programming

Thompson, Kirk G., Narcisse P. Bichot, and Jeffrey D. Schall. Dissociation of visual discrimination from saccade programming in macaque frontal eye field. J. Neurophysiol. 77: 1046–1050, 1997. To determine whether visual discrimination in macaque frontal eye field (FEF) is contingent on saccade planning, unit activity was recorded in two monkeys during blocked go and no-go visual search trials. The eye movements made by monkeys after correct no-go trials, in addition to an attenuation of the visual responses in no-go trials compared with go trials, indicated that covert saccade planning was effectively discouraged. During no-go search trials, the activity of the majority of neurons evolved to signal the location of the oddball stimulus. The degree and time course of the stimulus discrimination process observed in no-go trials was not different from that observed in go trials. We conclude that the discrimination of a salient visual stimulus reflected by FEF neurons is not contingent on saccade production but rather may reflect the outcome of an automatic visual selection process.

Discharge Properties of Neurons in the Rostral Superior Colliculus of the Monkey During Smooth-Pursuit Eye Movements

2000 ◽  
Vol 84 (2) ◽  
pp. 876-891 ◽  
Author(s):  
Richard J. Krauzlis ◽  
Michele A. Basso ◽  
Robert H. Wurtz
Keyword(s):  
Eye Movements ◽  
Superior Colliculus ◽  
Smooth Pursuit ◽  
Discharge Rate ◽  
Motor Command ◽  
Contralateral Side ◽  
Position Error ◽  
Related Activity ◽  
Tuning Curves ◽  
Pursuit Eye Movements

The intermediate and deep layers of the monkey superior colliculus (SC) comprise a retinotopically organized map for eye movements. The rostral end of this map, corresponding to the representation of the fovea, contains neurons that have been referred to as “fixation cells” because they discharge tonically during active fixation and pause during the generation of most saccades. These neurons also possess movement fields and are most active for targets close to the fixation point. Because the parafoveal locations encoded by these neurons are also important for guiding pursuit eye movements, we studied these neurons in two monkeys as they generated smooth pursuit. We found that fixation cells exhibit the same directional preferences during pursuit as during small saccades—they increase their discharge during movements toward the contralateral side and decrease their discharge during movements toward the ipsilateral side. This pursuit-related activity could be observed during saccade-free pursuit and was not predictive of small saccades that often accompanied pursuit. When we plotted the discharge rate from individual neurons during pursuit as a function of the position error associated with the moving target, we found tuning curves with peaks within a few degrees contralateral of the fovea. We compared these pursuit-related tuning curves from each neuron to the tuning curves for a saccade task from which we separately measured the visual, delay, and peri-saccadic activity. We found the highest and most consistent correlation with the delay activity recorded while the monkey viewed parafoveal stimuli during fixation. The directional preferences exhibited during pursuit can therefore be attributed to the tuning of these neurons for contralateral locations near the fovea. These results support the idea that fixation cells are the rostral extension of the buildup neurons found in the more caudal colliculus and that their activity conveys information about the size of the mismatch between a parafoveal stimulus and the currently foveated location. Because the generation of pursuit requires a break from fixation, the pursuit-related activity indicates that these neurons are not strictly involved with maintaining fixation. Conversely, because activity during the delay period was found for many neurons even when no eye movement was made, these neurons are also not obligatorily related to the generation of a movement. Thus the tonic activity of these rostral neurons provides a potential position-error signal rather than a motor command—a principle that may be applicable to buildup neurons elsewhere in the SC.

scholarly journals Time Course of Precision in Smooth-Pursuit Eye Movements of Monkeys

2007 ◽  
Vol 27 (11) ◽  
pp. 2987-2998 ◽  
Author(s):  
L. C. Osborne ◽  
S. S. Hohl ◽  
W. Bialek ◽  
S. G. Lisberger
Keyword(s):  
Eye Movements ◽  
Smooth Pursuit ◽  
Time Course ◽  
Smooth Pursuit Eye Movements ◽  
Pursuit Eye Movements

Central Ocular Motor Disorders: Clinical and Topographic Anatomical Diagnosis, Syndromes and Underlying Diseases

2021 ◽  
Vol 238 (11) ◽  
pp. 1197-1211
Author(s):  
Michael Leo Strupp ◽  
Dominik Straumann ◽  
Christoph Helmchen
Keyword(s):  
Eye Movements ◽  
Smooth Pursuit ◽  
Time Course ◽  
Metabolic Diseases ◽  
Spontaneous Nystagmus ◽  
Medial Longitudinal Fasciculus ◽  
Motor Disorders ◽  
Ocular Motor ◽  
Ocular Motor Disorders ◽  
Underlying Diseases

AbstractThe key to the diagnosis of ocular motor disorders is a systematic clinical examination of the different types of eye movements, including eye position, spontaneous nystagmus, range of eye movements, smooth pursuit, saccades, gaze-holding function, vergence, optokinetic nystagmus, as well as testing of the function of the vestibulo-ocular reflex (VOR) and visual fixation suppression of the VOR. This is like a window which allows you to look into the brain stem and cerebellum even if imaging is normal. Relevant anatomical structures are the midbrain, pons, medulla, cerebellum and rarely the cortex. There is a simple clinical rule: vertical and torsional eye movements are generated in the midbrain, horizontal eye movements in the pons. For example, isolated dysfunction of vertical eye movements is due to a midbrain lesion affecting the rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF), with impaired vertical saccades only or vertical gaze-evoked nystagmus due to dysfunction of the Interstitial nucleus of Cajal (INC). Lesions of the lateral medulla oblongata (Wallenberg syndrome) lead to typical findings: ocular tilt reaction, central fixation nystagmus and dysmetric saccades. The cerebellum is relevant for almost all types of eye movements; typical pathological findings are saccadic smooth pursuit, gaze-evoked nystagmus or dysmetric saccades. The time course of the development of symptoms and signs is important for the diagnosis of underlying diseases: acute: most likely stroke; subacute: inflammatory diseases, metabolic diseases like thiamine deficiencies; chronic progressive: inherited diseases like Niemann-Pick type C with typically initially vertical and then horizontal saccade palsy or degenerative diseases like progressive supranuclear palsy. Treatment depends on the underlying disease. In this article, we deal with central ocular motor disorders. In a second article, we focus on clinically relevant types of nystagmus such as downbeat, upbeat, fixation pendular, gaze-evoked, infantile or periodic alternating nystagmus. Therefore, these types of nystagmus will not be described here in detail.

Anticipatory sentence processing in children with specific language impairment: Evidence from eye movements during listening

2012 ◽  
Vol 34 (1) ◽  
pp. 5-44 ◽  
Author(s):  
LLORENÇ ANDREU ◽  
MÒNICA SANZ-TORRENT ◽  
JOHN C. TRUESWELL
Keyword(s):  
Eye Movements ◽  
Sentence Processing ◽  
Language Impairment ◽  
Specific Language Impairment ◽  
Time Course ◽  
Sentence Comprehension ◽  
Specific Language ◽  
Fine Grained ◽  
Anticipatory Eye Movements ◽  
And Control

ABSTRACTTwenty-five children with specific language impairment (SLI; age 5 years, 3 months [5;3]–8;2), 50 typically developing children (3;3–8;2), and 31 normal adults participated in three eye-tracking experiments of spoken language comprehension that were designed to investigate the use of verb information during real-time sentence comprehension in Spanish. In Experiment 1, participants heard sentences like El niño recorta con cuidado el papel (The boy trims carefully the paper) in the presence of four depicted objects, only one of which satisfied the semantic restrictions of the verb recorta (e.g., paper, clock, fox, and dinosaur). Eye movements revealed that children with SLI, like other groups, were able to recognize and retrieve the meaning of the verb rapidly enough to anticipate the upcoming semantically appropriate referent, prior to actually hearing the noun phrase el papel (the paper). Experiments 2 and 3 revealed that for all groups of participants, anticipatory eye movements were also modulated by the semantic fit of the object serving as the patient/theme of the verb. Relatively fine-grained semantic information of a verb was computed fast enough even by children with SLI to result in anticipatory eye movements to semantically appropriate referents. Children with SLI did differ from age-matched controls, but only slightly in terms of overall anticipatory looking at target objects; the time course of looking between these groups was quite similar. In addition, no differences were found between children with SLI and control children matched for mean length of utterance. Implications for theories that characterize SLI are discussed.

Supplementary Eye Fields Stimulation Facilitates Anticipatory Pursuit

2004 ◽  
Vol 92 (2) ◽  
pp. 1257-1262 ◽  
Author(s):  
M. Missal ◽  
S. J. Heinen
Keyword(s):  
Eye Movements ◽  
Smooth Pursuit ◽  
Neural Control ◽  
Target Motion ◽  
Motor Systems ◽  
Electrical Microstimulation ◽  
Pursuit Eye Movements ◽  
The Moment ◽  
Anticipatory Smooth Eye Movements ◽  
Supplementary Eye Fields

Anticipatory movements are motor responses occurring before likely sensory events in contrast to reflexive actions. Anticipatory movements are necessary to compensate for delays present in sensory and motor systems. Smooth pursuit eye movements are often used as a paradigmatic example for the study of anticipation. However, the neural control of anticipatory pursuit is unknown. A previous study suggested that the supplementary eye fields (SEFs) could play a role in the guidance of smooth pursuit to predictable target motion. In this study, we favored anticipatory responses in monkeys by making the parameters of target motion highly predictable and electrically stimulated the SEF before and during this behavior. Stimulation sites were restricted to regions of the SEF where saccades could not be evoked at the same low currents. We found that electrical microstimulation in the SEF increased the velocity of anticipatory pursuit movements and decreased their latency. These effects will be referred to as anticipatory pursuit facilitation. The degree of facilitation was the largest if the stimulation train was delivered near the end of the fixation period, before the moment when anticipatory pursuit usually begins. No anticipatory smooth eye movements could be evoked during fixation without an expectation of target motion. These results suggest that the SEF pursuit area might be involved in the process of guiding anticipatory pursuit.

Quantitative Analysis of Catch-Up Saccades During Sustained Pursuit

2002 ◽  
Vol 87 (4) ◽  
pp. 1772-1780 ◽  
Author(s):  
Sophie de Brouwer ◽  
Marcus Missal ◽  
Graham Barnes ◽  
Philippe Lefèvre
Keyword(s):  
Smooth Pursuit ◽  
Linear Regression Analysis ◽  
Multiple Linear Regression Analysis ◽  
Visual Axis ◽  
Retinal Slip ◽  
Different Types ◽  
Saccade Programming ◽  
Moving Stimulus ◽  
Catch Up ◽  
And Control

During visual tracking of a moving stimulus, primates orient their visual axis by combining two very different types of eye movements, smooth pursuit and saccades. The purpose of this paper was to investigate quantitatively the catch-up saccades occurring during sustained pursuit. We used a ramp-step-ramp paradigm to evoke catch-up saccades during sustained pursuit. In general, catch-up saccades followed the unexpected steps in position and velocity of the target. We observed catch-up saccades in the same direction as the smooth eye movement (forward saccades) as well as in the opposite direction (reverse saccades). We made a comparison of the main sequences of forward saccades, reverse saccades, and control saccades made to stationary targets. They were all three significantly different from each other and were fully compatible with the hypothesis that the smooth pursuit component is added to the saccadic component during catch-up saccades. A multiple linear regression analysis was performed on the saccadic component to find the parameters determining the amplitude of catch-up saccades. We found that both position error and retinal slip are taken into account in catch-up saccade programming to predict the future trajectory of the moving target. We also demonstrated that the saccadic system needs a minimum period of approximately 90 ms for taking into account changes in target trajectory. Finally, we reported a saturation (above 15°/s) in the contribution of retinal slip to the amplitude of catch-up saccades.

scholarly journals Dramatic impairment of prediction due to frontal lobe degeneration

2012 ◽  
Vol 108 (11) ◽  
pp. 2957-2966 ◽  
Author(s):  
Sébastien Coppe ◽  
Jean-Jacques Orban de Xivry ◽  
Demet Yüksel ◽  
Adrian Ivanoiu ◽  
Philippe Lefèvre
Keyword(s):  
Eye Movements ◽  
Smooth Pursuit ◽  
Frontal Lobes ◽  
Motion Blur ◽  
Moving Target ◽  
Motion Onset ◽  
Anticipatory Eye Movements ◽  
The Difference ◽  
Definition Of

Prediction is essential for motor function in everyday life. For instance, predictive mechanisms improve the perception of a moving target by increasing eye speed anticipatively, thus reducing motion blur on the retina. Subregions of the frontal lobes play a key role in eye movements in general and in smooth pursuit in particular, but their precise function is not firmly established. Here, the role of frontal lobes in the timing of predictive action is demonstrated by studying predictive smooth pursuit during transient blanking of a moving target in mild frontotemporal lobar degeneration (FTLD) and Alzheimer's disease (AD) patients. While control subjects and AD patients predictively reaccelerated their eyes before the predicted time of target reappearance, FTLD patients did not. The difference was so dramatic (classification accuracy >90%) that it could even lead to the definition of a new biomarker. In contrast, anticipatory eye movements triggered by the disappearance of the fixation point were still present before target motion onset in FTLD patients and visually guided pursuit was normal in both patient groups compared with controls. Therefore, FTLD patients were only impaired when the predicted timing of an external event was required to elicit an action. These results argue in favor of a role of the frontal lobes in predictive movement timing.

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