Temporal properties of visual motion signals for the initiation of smooth pursuit eye movements in monkeys

1994 ◽  
Vol 72 (1) ◽  
pp. 150-162 ◽  
Author(s):  
R. J. Krauzlis ◽  
S. G. Lisberger
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Visual Motion ◽  
Target Motion ◽  
Target Velocity ◽  
Motion Onset ◽  
Image Velocity ◽  
Pursuit Eye Movements ◽  
Onset Delay ◽  
The Relationship

1. Our goal was to assess whether visual motion signals related to changes in image velocity contribute to pursuit eye movements. We recorded the smooth eye movements evoked by ramp target motion at constant speed. In two different kinds of stimuli, the onset of target motion provided either an abrupt, step change in target velocity or a smooth target acceleration that lasted 125 ms followed by prolonged target motion at constant velocity. We measured the eye acceleration in the first 100 ms of pursuit. Because of the 100-ms latency from the onset of visual stimuli to the onset of smooth eye movement, the eye acceleration in this 100-ms interval provides an estimate of the open-loop response of the visuomotor pathways that drive pursuit. 2. For steps of target velocity, eye acceleration in the first 100 ms of pursuit depended on the “motion onset delay,” defined as the interval between the appearance of the target and the onset of motion. If the motion onset delay was > 100 ms, then the initial eye movement consisted of separable early and late phases of eye acceleration. The early phase dominated eye acceleration in the interval from 0 to 40 ms after pursuit onset and was relatively insensitive to image speed. The late phase dominated eye acceleration in the interval 40–100 ms after the onset of pursuit and had an amplitude that was proportional to image speed. If there was no delay between the appearance of the target and the onset of its motion, then the early component was not seen, and eye acceleration was related to target speed throughout the first 100 ms of pursuit. 3. For step changes of target velocity, the relationship between eye acceleration in the first 40 ms of pursuit and target velocity saturated at target speeds > 10 degrees /s. In contrast, the relationship was nearly linear when eye acceleration was measured in the interval 40–100 ms after the onset of pursuit. We suggest that the first 40 ms of pursuit are driven by a transient visual motion input that is related to the onset of target motion (motion onset transient component) and that the next 60 ms are driven by a sustained visual motion input (image velocity component). 4. When the target accelerated smoothly for 125 ms before moving at constant speed, the initiation of pursuit resembled that evoked by steps of target velocity. However, the latency of pursuit was consistently longer for smooth target accelerations than for steps of target velocity.(ABSTRACT TRUNCATED AT 400 WORDS)

Postsaccadic Enhancement of Initiation of Smooth Pursuit Eye Movements in Monkeys

1998 ◽  
Vol 79 (4) ◽  
pp. 1918-1930 ◽  
Author(s):  
Stephen G. Lisberger
Keyword(s):  
Eye Movements ◽  
Smooth Pursuit ◽  
Visual Motion ◽  
Target Position ◽  
Target Motion ◽  
Target Velocity ◽  
Smooth Pursuit Eye Movements ◽  
Motor Pathways ◽  
Pursuit Eye Movements ◽  
Eye Velocity

Lisberger, Stephen G. Postsaccadic enhancement of initiation of smooth pursuit eye movements in monkeys. J. Neurophysiol. 79: 1918–1930, 1998. Step-ramp target motion evokes a characteristic sequence of presaccadic smooth eye movement in the direction of the target ramp, catch-up targets to bring eye position close to the position of the moving target, and postsaccadic eye velocities that nearly match target velocity. I have analyzed this sequence of eye movements in monkeys to reveal a strong postsaccadic enhancement of pursuit eye velocity and to document the conditions that lead to that enhancement. Smooth eye velocity was measured in the last 10 ms before and the first 10 ms after the first saccade evoked by step-ramp target motion. Plots of eye velocity as a function of time after the onset of the target ramp revealed that eye velocity at a given time was much higher if measured after versus before the saccade. Postsaccadic enhancement of pursuit was recorded consistently when the target stepped 3° eccentric on the horizontal axis and moved upward, downward, or away from the position of fixation. To determine whether postsaccadic enhancement of pursuit was invoked by smear of the visual scene during a saccade, I recorded the effect of simulated saccades on the presaccadic eye velocity for step-ramp target motion. The 3° simulated saccade, which consisted of motion of a textured background at 150°/s for 20 ms, failed to cause any enhancement of presaccadic eye velocity. By using a strategically selected set of oblique target steps with horizontal ramp target motion, I found clear enhancement for saccades in all directions, even those that were orthogonal to target motion. When the size of the target step was varied by up to 15° along the horizontal meridian, postsaccadic eye velocity did not depend strongly either on the initial target position or on whether the target moved toward or away from the position of fixation. In contrast, earlier studies and data in this paper show that presaccadic eye velocity is much stronger when the target is close to the center of the visual field and when the target moves toward versus away from the position of fixation. I suggest that postsaccadic enhancement of pursuit reflects activation, by saccades, of a switch that regulates the strength of transmission through the visual-motor pathways for pursuit. Targets can cause strong visual motion signals but still evoke low presaccadic eye velocities if they are ineffective at activating the pursuit system.

scholarly journals Role of Primate Cerebellar Hemisphere in Voluntary Eye Movement Control Revealed by Lesion Effects

2009 ◽  
Vol 101 (2) ◽  
pp. 934-947 ◽  
Author(s):  
Masafumi Ohki ◽  
Hiromasa Kitazawa ◽  
Takahito Hiramatsu ◽  
Kimitake Kaga ◽  
Taiko Kitamura ◽  
...  
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Smooth Pursuit ◽  
Movement Control ◽  
Cerebellar Hemisphere ◽  
Target Velocity ◽  
Eye Movement Control ◽  
Pursuit Eye Movements ◽  
Catch Up

The anatomical connection between the frontal eye field and the cerebellar hemispheric lobule VII (H-VII) suggests a potential role of the hemisphere in voluntary eye movement control. To reveal the involvement of the hemisphere in smooth pursuit and saccade control, we made a unilateral lesion around H-VII and examined its effects in three Macaca fuscata that were trained to pursue visually a small target. To the step (3°)-ramp (5–20°/s) target motion, the monkeys usually showed an initial pursuit eye movement at a latency of 80–140 ms and a small catch-up saccade at 140–220 ms that was followed by a postsaccadic pursuit eye movement that roughly matched the ramp target velocity. After unilateral cerebellar hemispheric lesioning, the initial pursuit eye movements were impaired, and the velocities of the postsaccadic pursuit eye movements decreased. The onsets of 5° visually guided saccades to the stationary target were delayed, and their amplitudes showed a tendency of increased trial-to-trial variability but never became hypo- or hypermetric. Similar tendencies were observed in the onsets and amplitudes of catch-up saccades. The adaptation of open-loop smooth pursuit velocity, tested by a step increase in target velocity for a brief period, was impaired. These lesion effects were recognized in all directions, particularly in the ipsiversive direction. A recovery was observed at 4 wk postlesion for some of these lesion effects. These results suggest that the cerebellar hemispheric region around lobule VII is involved in the control of smooth pursuit and saccadic eye movements.

scholarly journals Spatial and Temporal Integration of Visual Motion Signals for Smooth Pursuit Eye Movements in Monkeys

2009 ◽  
Vol 102 (4) ◽  
pp. 2013-2025 ◽  
Author(s):  
Leslie C. Osborne ◽  
Stephen G. Lisberger
Keyword(s):  
Random Walk ◽  
Eye Movements ◽  
Smooth Pursuit ◽  
Visual Motion ◽  
Target Motion ◽  
Linear Filter ◽  
Smooth Pursuit Eye Movements ◽  
Spatial Averaging ◽  
Spatial Integration ◽  
Pursuit Eye Movements

To probe how the brain integrates visual motion signals to guide behavior, we analyzed the smooth pursuit eye movements evoked by target motion with a stochastic component. When each dot of a texture executed an independent random walk such that speed or direction varied across the spatial extent of the target, pursuit variance increased as a function of the variance of visual pattern motion. Noise in either target direction or speed increased the variance of both eye speed and direction, implying a common neural noise source for estimating target speed and direction. Spatial averaging was inefficient for targets with >20 dots. Together these data suggest that pursuit performance is limited by the properties of spatial averaging across a noisy population of sensory neurons rather than across the physical stimulus. When targets executed a spatially uniform random walk in time around a central direction of motion, an optimized linear filter that describes the transformation of target motion into eye motion accounted for ∼50% of the variance in pursuit. Filters had widths of ∼25 ms, much longer than the impulse response of the eye, and filter shape depended on both the range and correlation time of motion signals, suggesting that filters were products of sensory processing. By quantifying the effects of different levels of stimulus noise on pursuit, we have provided rigorous constraints for understanding sensory population decoding. We have shown how temporal and spatial integration of sensory signals converts noisy population responses into precise motor responses.

scholarly journals Enhancement of Multiple Components of Pursuit Eye Movement by Microstimulation in the Arcuate Frontal Pursuit Area in Monkeys

2002 ◽  
Vol 87 (2) ◽  
pp. 802-818 ◽  
Author(s):  
Masaki Tanaka ◽  
Stephen G. Lisberger
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Visual Motion ◽  
Gain Control ◽  
Target Velocity ◽  
Stationary Target ◽  
Electrical Microstimulation ◽  
Eye Motion ◽  
On Line ◽  
Eye Velocity

Periarcuate frontal cortex is involved in the control of smooth pursuit eye movements, but its role remains unclear. To better understand the control of pursuit by the “frontal pursuit area” (FPA), we applied electrical microstimulation when the monkeys were performing a variety of oculomotor tasks. In agreement with previous studies, electrical stimulation consisting of a train of 50-μA pulses at 333 Hz during fixation of a stationary target elicited smooth eye movements with a short latency (∼26 ms). The size of the elicited smooth eye movements was enhanced when the stimulation pulses were delivered during the maintenance of pursuit. The enhancement increased as a function of ongoing pursuit speed and was greater during pursuit in the same versus opposite direction of the eye movements evoked at a site. If stimulation was delivered during pursuit in eight different directions, the elicited eye velocity was fit best by a model incorporating two stimulation effects: a directional signal that drives eye velocity and an increase in the gain of ongoing pursuit eye speed in all directions. Separate experiments tested the effect of stimulation on the response to specific image motions. Stimulation consisted of a train of pulses at 100 or 200 Hz delivered during fixation so that only small smooth eye movements were elicited. If the stationary target was perturbed briefly during microstimulation, normally weak eye movement responses showed strong enhancement. If delivered at the initiation of pursuit, the same microstimulation caused enhancement of the presaccadic initiation of pursuit for steps of target velocity that moved the target either away from the position of fixation or in the direction of the eye movement caused by stimulation at the site. Stimulation in the FPA increased the latency of saccades to stationary or moving targets. Our results show that the FPA has two kinds of effects on the pursuit system. One drives smooth eye velocity in a fixed direction and is subject to on-line gain control by ongoing pursuit. The other causes enhancement of both the speed of ongoing pursuit and the responses to visual motion in a way that is not strongly selective for the direction of pursuit. Enhancement may operate either at a single site or at multiple sites. We conclude that the FPA plays an important role in on-line gain control for pursuit as well as possibly delivering commands for the direction and speed of smooth eye motion.

scholarly journals Motion dependence of smooth pursuit eye movements in the marmoset

2015 ◽  
Vol 113 (10) ◽  
pp. 3954-3960 ◽  
Author(s):  
Jude F. Mitchell ◽  
Nicholas J. Priebe ◽  
Cory T. Miller
Keyword(s):  
Eye Movements ◽  
Smooth Pursuit ◽  
Visual Motion ◽  
Genetic Model ◽  
Mental Disease ◽  
Target Velocity ◽  
Smooth Pursuit Eye Movements ◽  
Pursuit Eye Movements ◽  
Slow Moving ◽  
Eye Velocity

Smooth pursuit eye movements stabilize slow-moving objects on the retina by matching eye velocity with target velocity. Two critical components are required to generate smooth pursuit: first, because it is a voluntary eye movement, the subject must select a target to pursue to engage the tracking system; and second, generating smooth pursuit requires a moving stimulus. We examined whether this behavior also exists in the common marmoset, a New World primate that is increasingly attracting attention as a genetic model for mental disease and systems neuroscience. We measured smooth pursuit in two marmosets, previously trained to perform fixation tasks, using the standard Rashbass step-ramp pursuit paradigm. We first measured the aspects of visual motion that drive pursuit eye movements. Smooth eye movements were in the same direction as target motion, indicating that pursuit was driven by target movement rather than by displacement. Both the open-loop acceleration and closed-loop eye velocity exhibited a linear relationship with target velocity for slow-moving targets, but this relationship declined for higher speeds. We next examined whether marmoset pursuit eye movements depend on an active engagement of the pursuit system by measuring smooth eye movements evoked by small perturbations of motion from fixation or during pursuit. Pursuit eye movements were much larger during pursuit than from fixation, indicating that pursuit is actively gated. Several practical advantages of the marmoset brain, including the accessibility of the middle temporal (MT) area and frontal eye fields at the cortical surface, merit its utilization for studying pursuit movements.

The effect of a moving distractor on the initiation of smooth-pursuit eye movements

1997 ◽  
Vol 14 (2) ◽  
pp. 323-338 ◽  
Author(s):  
Vincent P. Ferrera ◽  
Stephen G. Lisberger
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Smooth Pursuit ◽  
Visual Motion ◽  
Target Selection ◽  
Motion Processing ◽  
Smooth Pursuit Eye Movements ◽  
Response Preparation ◽  
Pursuit Eye Movements ◽  
Visual Motion Processing

AbstractAs a step toward understanding the mechanism by which targets are selected for smooth-pursuit eye movements, we examined the behavior of the pursuit system when monkeys were presented with two discrete moving visual targets. Two rhesus monkeys were trained to select a small moving target identified by its color in the presence of a moving distractor of another color. Smooth-pursuit eye movements were quantified in terms of the latency of the eye movement and the initial eye acceleration profile. We have previously shown that the latency of smooth pursuit, which is normally around 100 ms, can be extended to 150 ms or shortened to 85 ms depending on whether there is a distractor moving in the opposite or same direction, respectively, relative to the direction of the target. We have now measured this effect for a 360 deg range of distractor directions, and distractor speeds of 5–45 deg/s. We have also examined the effect of varying the spatial separation and temporal asynchrony between target and distractor. The results indicate that the effect of the distractor on the latency of pursuit depends on its direction of motion, and its spatial and temporal proximity to the target, but depends very little on the speed of the distractor. Furthermore, under the conditions of these experiments, the direction of the eye movement that is emitted in response to two competing moving stimuli is not a vectorial combination of the stimulus motions, but is solely determined by the direction of the target. The results are consistent with a competitive model for smooth-pursuit target selection and suggest that the competition takes place at a stage of the pursuit pathway that is between visual-motion processing and motor-response preparation.

Influence of Cognitive Expectation on the Initiation of Anticipatory and Visual Pursuit Eye Movements in the Rhesus Monkey

2006 ◽  
Vol 95 (6) ◽  
pp. 3770-3782 ◽  
Author(s):  
C. de Hemptinne ◽  
P. Lefèvre ◽  
M. Missal
Keyword(s):  
Eye Movements ◽  
Rhesus Monkeys ◽  
Dominant Role ◽  
Visual Display ◽  
Target Motion ◽  
Motion Onset ◽  
Directional Information ◽  
Visual Pursuit ◽  
Pursuit Eye Movements

A classic paradigm to study anticipatory pursuit consists in training monkeys to look at a target that appears in the center of a visual display, disappears during a short “gap” period, then reappears and immediately starts to move. To determine the role of prior directional information on anticipatory pursuit eye movements, we trained rhesus monkeys to associate the color of a centrally presented visual cue with the direction of an upcoming target motion. In a first experiment, a gap period occurred randomly in 50% of the trials. Consequently, two possible choices of timing of target motion onset were given to subjects to guide their anticipatory responses. In a second experiment, a gap period occurred during each trial and only a single choice of timing of target motion onset was given to subjects. We found that monkeys used the learned association between the color of the cue and the direction of future target motion to voluntarily initiate anticipatory pursuit movements in the appropriate direction. Anticipatory movements could be classified in two distinct populations: early and late movements. Early movements were most frequent when prior directional information was provided and when two choices of timing of target motion onset were given. The latency of visual pursuit was shortened and its velocity was larger when prior directional information was provided. We conclude that cognitive expectation of future target motion plays a dominant role in determining characteristics of anticipatory pursuit in the monkey.

Topographic and directional organization of visual motion inputs for the initiation of horizontal and vertical smooth-pursuit eye movements in monkeys

1989 ◽  
Vol 61 (1) ◽  
pp. 173-185 ◽  
Author(s):  
S. G. Lisberger ◽  
T. A. Pavelko
Keyword(s):  
Eye Movements ◽  
Visual Field ◽  
Visual Motion ◽  
Target Position ◽  
Target Motion ◽  
Visual Signals ◽  
Motion Processing ◽  
Pursuit Eye Movements ◽  
Visual Inputs ◽  
Initial Target

1. The goal of our study was to determine the properties of the visual inputs for pursuit eye movements. In a previous study we presented horizontal target motion along the horizontal meridian and showed that targets were more effective if they moved across the center of the visual field. We have now analyzed the topographic weighting of the inputs for pursuit in greater detail, using targets that moved in all directions and across a wide area of the visual field. 2. Monkeys were rewarded for tracking targets that started at 48 positions in the visual field. The initial positions were spaced equally around 4 circles that were centered at the position of fixation and had radii of 3, 6, 9, and 12 degrees. Targets moved horizontally or vertically at 30 degrees/s. We measured the smooth eye acceleration in the first 80 ms after the initiation of pursuit, before there had been time for visual feedback to affect the position or velocity of the retinal images from the target. 3. For both horizontal and vertical target motion, there were major differences between the early and late intervals in the first 80 ms of pursuit. In the first 20 ms eye acceleration was largely independent of initial target position. In later intervals eye acceleration decreased sharply as a function of initial target eccentricity. The later intervals also showed a pronounced toward/away asymmetry such that the initiation of pursuit was more vigorous for target motion toward than for motion away from the horizontal or vertical meridian. 4. Comparison of the topographic organization of the middle temporal visual area (MT) with our data on pursuit suggests that the topography of cortical maps is smoothed when the visual signals are transmitted to the pursuit system. For example, the superior visual hemifield is underrepresented in cortical motion processing areas, but target motion in the superior and inferior visual hemifields is equally effective for the initiation of pursuit. 5. We investigated the directional organization of the visual inputs for pursuit by presenting targets that started at 6 degrees eccentric and moved in 16 different directions. Horizontal target motion always evoked larger eye accelerations than did vertical target motion. Target motion in oblique directions evoked intermediate values of eye acceleration. 6. Our data show two classes of variation in pursuit performance. First, some subjects showed ideosyncratic variations that were restricted to one hemifield or one direction of target motion. We attribute these variations to differences among subjects in the physiology of visual pathways.(ABSTRACT TRUNCATED AT 400 WORDS)

Effect of changing feedback delay on spontaneous oscillations in smooth pursuit eye movements of monkeys

1992 ◽  
Vol 67 (3) ◽  
pp. 625-638 ◽  
Author(s):  
D. Goldreich ◽  
R. J. Krauzlis ◽  
S. G. Lisberger
Keyword(s):  
Eye Movements ◽  
Visual Feedback ◽  
Target Motion ◽  
Image Motion ◽  
Target Velocity ◽  
Feedback Delay ◽  
Total Delay ◽  
Internal Feedback ◽  
Pursuit Eye Movements ◽  
Eye Velocity

1. Our goal was to discriminate between two classes of models for pursuit eye movements. The monkey's pursuit system and both classes of model exhibit oscillations around target velocity during tracking of ramp target motion. However, the mechanisms that determine the frequency of oscillations differ in the two classes of model. In "internal feedback" models, oscillations are controlled by internal feedback loops, and the frequency of oscillation does not depend strongly on the delay in visual feedback. In "image motion" models, oscillations are controlled by visual feedback, and the frequency of oscillation does depend on the delay in visual feedback. 2. We measured the frequency of oscillation during pursuit of ramp target motion as a function of the total delay for visual feedback. For the shortest feedback delays of approximately 70 ms, the frequency of oscillation was between 6 and 7 Hz. Increases in feedback delay caused decreases in the frequency of oscillation. The effect of increasing feedback delay was similar, whether the increases were produced naturally by dimming and decreasing the size of the tracking target or artificially with the computer. We conclude that the oscillations in eye velocity during pursuit of ramp target motion are controlled by visual inputs, as suggested by the image motion class of models. 3. Previous experiments had suggested that the visuomotor pathways for pursuit are unable to respond well to frequencies as high as the 6-7 Hz at which eye velocity oscillates in monkeys. We therefore tested the response to target vibration at an amplitude of +/- 8 degrees/s and frequencies as high as 15 Hz. For target vibration at 6 Hz, the gain of pursuit, defined as the amplitude of eye velocity divided by the amplitude of target velocity, was as high as 0.65. We conclude that the visuomotor pathways for pursuit are capable of processing image motion at high temporal frequencies. 4. The gain of pursuit was much larger when the target vibrated around a constant speed of 15 degrees/s than when it vibrated around a stationary position. This suggests that the pursuit pathways contain a switch that must be closed to allow the visuomotor pathways for pursuit to operate at their full gain. The switch apparently remains open for target vibration around a stationary position. 5. The responses to target vibration revealed a frequency at which eye velocity lagged target velocity by 180 degrees and at which one monkey showed a local peak in the gain of pursuit.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Context-Dependent Smooth Eye Movements Evoked by Stationary Visual Stimuli in Trained Monkeys

2000 ◽  
Vol 84 (4) ◽  
pp. 1748-1762 ◽  
Author(s):  
Masaki Tanaka ◽  
Stephen G. Lisberger
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Gain Control ◽  
Target Motion ◽  
Target Velocity ◽  
Moving Targets ◽  
On Line ◽  
Controlling Element ◽  
Vector Averaging ◽  
The Right

The appearance of a stationary but irrelevant cue triggers a smooth eye movement away from the position of the cue in monkeys that have been trained extensively to smoothly track the motion of moving targets while not making saccades to the stationary cue. We have analyzed the parameters that regulate the size of the cue-evoked smooth eye movement and examined whether presentation of the cue changes the initiation of pursuit for subsequent steps of target velocity. Cues evoked smooth eye movements in blocks of target motions that required smooth pursuit to moving targets, but evoked much smaller smooth eye movements in blocks that required saccades to stationary targets. The direction of the cue-evoked eye movement was always opposite to the position of the cue and did not depend on whether subsequent target motion was toward or away from the position of fixation. The latency of the cue-evoked smooth eye movement was near 100 ms and was slightly longer than the latency of pursuit for target motion away from the position of fixation. The size of the cue-evoked smooth eye movement was as large as 10°/s and decreased as functions of the eccentricity of the cue and the illumination of the experimental room. To study the initiation of pursuit in the wake of the cues, we used bilateral cues at equal eccentricities to the right and left of the position of fixation. These evoked smaller eye velocities that were consistent with vector averaging of the responses to each cue. In the wake of bilateral cues, the initiation of pursuit was enhanced for target motion away from the position of fixation, but not for target motion toward the position of fixation. We suggest that the cue-evoked smooth eye movement is related to a previously postulated on-line gain control for pursuit, and that it is a side-effect of sudden activation of the gain-controlling element.

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