scholarly journals Pursuit Speed Compensation in Cortical Area MSTd

2002 ◽  
Vol 88 (5) ◽  
pp. 2630-2647 ◽  
Author(s):  
Krishna V. Shenoy ◽  
James A. Crowell ◽  
Richard A. Andersen
Keyword(s):  
Eye Movements ◽  
Retinal Image ◽  
Visual Motion ◽  
Object Motion ◽  
Retinal Position ◽  
Temporal Area ◽  
Pursuit Eye Movements ◽  
Medial Superior Temporal ◽  
The Difference ◽  
Pursuit Velocity

When we move forward the visual images on our retinas expand. Humans rely on the focus, or center, of this expansion to estimate their direction of self-motion or heading and, as long as the eyes are still, the retinal focus corresponds to the heading. However, smooth pursuit eye movements add visual motion to the expanding retinal image and displace the focus of expansion. In spite of this, humans accurately judge their heading during pursuit eye movements even though the retinal focus no longer corresponds to the heading. Recent studies in macaque suggest that correction for pursuit may occur in the dorsal aspect of the medial superior temporal area (MSTd); neurons in this area are tuned to the retinal position of the focus and they modify their tuning to partially compensate for the focus shift caused by pursuit. However, the question remains whether these neurons shift focus tuning more at faster pursuit speeds, to compensate for the larger focus shifts created by faster pursuit. To investigate this question, we recorded from 40 MSTd neurons while monkeys made pursuit eye movements at a range of speeds across simulated self- or object motion displays. We found that most MSTd neurons modify their focus tuning more at faster pursuit speeds, consistent with the idea that they encode heading and other motion parameters regardless of pursuit speed. Across the population, the median rate of compensation increase with pursuit speed was 51% as great as required for perfect compensation. We recorded from the same neurons in a simulated pursuit condition, in which gaze was fixed but the entire display counter-rotated to produce the same retinal image as during real pursuit. This condition yielded the result that retinal cues contribute to pursuit compensation; the rate of compensation increase was 30% of that required for accurate encoding of heading. The difference between these two conditions was significant ( P < 0.05), indicating that extraretinal cues also contribute significantly. We found a systematic antialignment between preferred pursuit and preferred visual motion directions. Neurons may use this antialignment to combine retinal and extraretinal compensatory cues. These results indicate that many MSTd neurons compensate for pursuit velocity, pursuit direction as previously reported and pursuit speed, and further implicate MSTd as a critical stage in the computation of egomotion.

Pursuit and optokinetic deficits following chemical lesions of cortical areas MT and MST

1988 ◽  
Vol 60 (3) ◽  
pp. 940-965 ◽  
Author(s):  
M. R. Dursteler ◽  
R. H. Wurtz
Keyword(s):  
Eye Movements ◽  
Visual Field ◽  
Visual Motion ◽  
Ibotenic Acid ◽  
Motion Processing ◽  
Temporal Area ◽  
Target Speed ◽  
Pursuit Eye Movements ◽  
Medial Superior Temporal ◽  
Visual Motion Processing

1. Previous experiments have shown that punctate chemical lesions within the middle temporal area (MT) of the superior temporal sulcus (STS) produce deficits in the initiation and maintenance of pursuit eye movements (10, 34). The present experiments were designed to test the effect of such chemical lesions in an area within the STS to which MT projects, the medial superior temporal area (MST). 2. We injected ibotenic acid into localized regions of MST, and we observed two deficits in pursuit eye movements, a retinotopic deficit and a directional deficit. 3. The retinotopic deficit in pursuit initiation was characterized by the monkey's inability to match eye speed to target speed or to adjust the amplitude of the saccade made to acquire the target to compensate for target motion. This deficit was related to the initiation of pursuit to targets moving in any direction in the visual field contralateral to the side of the brain with the lesion. This deficit was similar to the deficit we found following damage to extrafoveal MT except that the affected area of the visual field frequently extended throughout the entire contralateral visual field tested. 4. The directional deficit in pursuit maintenance was characterized by a failure to match eye speed to target speed once the fovea had been brought near the moving target. This deficit occurred only when the target was moving toward the side of the lesion, regardless of whether the target began to move in the ipsilateral or contralateral visual field. There was no deficit in the amplitude of saccades made to acquire the target, or in the amplitude of the catch-up saccades made to compensate for the slowed pursuit. The directional deficit is similar to the one we described previously following chemical lesions of the foveal representation in the STS. 5. Retinotopic deficits resulted from any of our injections in MST. Directional deficits resulted from lesions limited to subregions within MST, particularly lesions that invaded the floor of the STS and the posterior bank of the STS just lateral to MT. Extensive damage to the densely myelinated area of the anterior bank or to the posterior parietal area on the dorsal lip of the anterior bank produced minimal directional deficits. 6. We conclude that damage to visual motion processing in MST underlies the retinotopic pursuit deficit just as it does in MT. MST appears to be a sequential step in visual motion processing that occurs before all of the visual motion information is transmitted to the brainstem areas related to pursuit.(ABSTRACT TRUNCATED AT 400 WORDS)

Modulation of pursuit eye movements by stimulation of cortical areas MT and MST

1989 ◽  
Vol 62 (1) ◽  
pp. 31-47 ◽  
Author(s):  
H. Komatsu ◽  
R. H. Wurtz
Keyword(s):  
Eye Movements ◽  
Visual Motion ◽  
Directional Bias ◽  
Position Information ◽  
Temporal Area ◽  
Pursuit Eye Movements ◽  
Visual Motion Processing ◽  
Pursuit System ◽  
Pursuit Velocity ◽  
The Brain

1. Many cells in the superior temporal sulcus (STS) of the monkey that represent the foveal region of the visual field discharge during pursuit eye movements. Damage to these areas produces a deficit in the maintenance of pursuit eye movements when the target towards the side of the brain with the lesion. In the present experiments, we electrically stimulated these areas to better localize and understand the mechanisms underlying this directional pursuit deficit. 2. Monkeys were trained to pursue a moving target using a step-ramp task in which the target first stepped to an eccentric position and then moved smoothly across the screen. Trains of stimulation were applied after the monkey had begun to pursue the target to study stimulation effects of maintenance of pursuit. 3. Stimulation during pursuit frequently produced eye acceleration toward the side of the brain stimulated. Eye speed increased during pursuit toward the side stimulated and decreased during pursuit away from the side stimulated. This increase in velocity toward the side of the brain where stimulation presumably activated cells is consistent with the decrease in pursuit velocity toward the side of the brain after cells were removed by chemical lesions. 4. The increase or decrease in pursuit speed following stimulation produced a slip of the target on the retina. The pursuit system seemed to be insensitive to this slip during the period of stimulation, however, since the effect of stimulation during pursuit of a stabilized image (open-loop condition) was similar to that resulting from stimulation under normal pursuit conditions (closed-loop). This insensitivity to visual motion during stimulation suggests that the stimulation substitutes for that visual input. 5. The separation of eye and target position that resulted from stimulation did produce catch-up saccades. This provides added evidence that alteration of middle temporal area (MT) and medial superior temporal area (MST) modifies visual-motion but not visual-position information. 6. Stimulation that produced eye acceleration during pursuit produced only a slight effect during fixation of a stationary target. The effectiveness of the stimulation also increased as the speed of the pursuit increased between 5 and 25 degrees/s. These observations, which show that pursuit velocity altered the effect of stimulation, suggest that the stimulation acted on visual motion processing before information about the pursuit movement itself is incorporated. Since this stimulation produces directional pursuit effects, we hypothesize that the directional bias for pursuit originates in the visual signal conveyed to the pursuit system.(ABSTRACT TRUNCATED AT 400 WORDS)

MST Neuronal Responses to Heading Direction During Pursuit Eye Movements

1999 ◽  
Vol 81 (2) ◽  
pp. 596-610 ◽  
Author(s):  
William K. Page ◽  
Charles J. Duffy
Keyword(s):  
Eye Movements ◽  
Smooth Pursuit ◽  
Visual Motion ◽  
Neuronal Population ◽  
Smooth Pursuit Eye Movements ◽  
Neuronal Responses ◽  
Temporal Area ◽  
Pursuit Eye Movements ◽  
Heading Direction ◽  
Monkey Visual Cortex

MST neuronal responses to heading direction during pursuit eye movements. As you move through the environment, you see a radial pattern of visual motion with a focus of expansion (FOE) that indicates your heading direction. When self-movement is combined with smooth pursuit eye movements, the turning of the eye distorts the retinal image of the FOE but somehow you still can perceive heading. We studied neurons in the medial superior temporal area (MST) of monkey visual cortex, recording responses to FOE stimuli presented during fixation and smooth pursuit eye movements. Almost all neurons showed significant changes in their FOE selective responses during pursuit eye movements. However, the vector average of all the neuronal responses indicated the direction of the FOE during both fixation and pursuit. Furthermore, the amplitude of the net vector increased with increasing FOE eccentricity. We conclude that neuronal population encoding in MST might contribute to pursuit-tolerant heading perception.

scholarly journals Processing of object motion and self-motion in the lateral subdivision of the medial superior temporal area in macaques

2019 ◽  
Vol 121 (4) ◽  
pp. 1207-1221 ◽  
Author(s):  
Ryo Sasaki ◽  
Dora E. Angelaki ◽  
Gregory C. DeAngelis
Keyword(s):  
Visual Cues ◽  
Moving Objects ◽  
Visual Motion ◽  
Object Motion ◽  
Image Motion ◽  
Motion Processing ◽  
Temporal Area ◽  
Medial Superior Temporal ◽  
Visual Motion Processing ◽  
Self Motion

Multiple areas of macaque cortex are involved in visual motion processing, but their relative functional roles remain unclear. The medial superior temporal (MST) area is typically divided into lateral (MSTl) and dorsal (MSTd) subdivisions that are thought to be involved in processing object motion and self-motion, respectively. Whereas MSTd has been studied extensively with regard to processing visual and nonvisual self-motion cues, little is known about self-motion signals in MSTl, especially nonvisual signals. Moreover, little is known about how self-motion and object motion signals interact in MSTl and how this differs from interactions in MSTd. We compared the visual and vestibular heading tuning of neurons in MSTl and MSTd using identical stimuli. Our findings reveal that both visual and vestibular heading signals are weaker in MSTl than in MSTd, suggesting that MSTl is less well suited to participate in self-motion perception than MSTd. We also tested neurons in both areas with a variety of combinations of object motion and self-motion. Our findings reveal that vestibular signals improve the separability of coding of heading and object direction in both areas, albeit more strongly in MSTd due to the greater strength of vestibular signals. Based on a marginalization technique, population decoding reveals that heading and object direction can be more effectively dissociated from MSTd responses than MSTl responses. Our findings help to clarify the respective contributions that MSTl and MSTd make to processing of object motion and self-motion, although our conclusions may be somewhat specific to the multipart moving objects that we employed. NEW & NOTEWORTHY Retinal image motion reflects contributions from both the observer’s self-motion and the movement of objects in the environment. The neural mechanisms by which the brain dissociates self-motion and object motion remain unclear. This study provides the first systematic examination of how the lateral subdivision of area MST (MSTl) contributes to dissociating object motion and self-motion. We also examine, for the first time, how MSTl neurons represent translational self-motion based on both vestibular and visual cues.

Relation of cortical areas MT and MST to pursuit eye movements. I. Localization and visual properties of neurons

1988 ◽  
Vol 60 (2) ◽  
pp. 580-603 ◽  
Author(s):  
H. Komatsu ◽  
R. H. Wurtz
Keyword(s):  
Eye Movements ◽  
Smooth Pursuit ◽  
Visual Motion ◽  
Receptive Fields ◽  
Motion Processing ◽  
Temporal Area ◽  
Pursuit Eye Movements ◽  
Visual Motion Processing ◽  
Visual Areas ◽  
Visual Properties

1. Among the multiple extrastriate visual areas in monkey cerebral cortex, several areas within the superior temporal sulcus (STS) are selectively related to visual motion processing. In this series of experiments we have attempted to relate this visual motion processing at a neuronal level to a behavior that is dependent on such processing, the generation of smooth-pursuit eye movements. 2. We studied two visual areas within the STS, the middle temporal area (MT) and the medial superior temporal area (MST). For the purposes of this study, MT and MST were defined functionally as those areas within the STS having a high proportion of directionally selective neurons. MST was distinguished from MT by using the established relationship of receptive-field size to eccentricity, with MST having larger receptive fields than MT. 3. A subset of these visually responsive cells within the STS were identified as pursuit cells--those cells that discharge during smooth pursuit of a small target in an otherwise dark room. Pursuit cells were found only in localized regions--in the foveal region of MT (MTf), in a dorsal-medial area of MST on the anterior bank of the STS (MSTd), and in a lateral-anterior area of MST on the floor and the posterior bank of the STS (MST1). 4. Pursuit cells showed two characteristics in common when their visual properties were studied while the monkey was fixating. Almost all cells showed direction selectivity for moving stimuli and included the fovea within their receptive fields. 5. The visual response of pursuit cells in the several areas differed in two ways. Cells in MTf preferred small moving spots of light, whereas cells in MSTd preferred large moving stimuli, such as a pattern of random dots. Cells in MTf had small receptive fields; those in MSTd usually had large receptive fields. Visual responses of pursuit neurons in MST1 were heterogeneous; some resembled those in MTf, whereas others were similar to those in MSTd. This suggests that the pursuit cells in MSTd and MST1 belong to different subregions of MST.

MST Neurons Code for Visual Motion in Space Independent of Pursuit Eye Movements

2007 ◽  
Vol 97 (5) ◽  
pp. 3473-3483 ◽  
Author(s):  
Naoko Inaba ◽  
Shigeru Shinomoto ◽  
Shigeru Yamane ◽  
Aya Takemura ◽  
Kenji Kawano
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Visual Motion ◽  
Neural Mechanism ◽  
Mt Neurons ◽  
Pursuit Eye Movements ◽  
Medial Superior Temporal ◽  
Counter Rotation ◽  
Induced Motion ◽  
Mst Neurons

When a person tracks a small moving object, the visual images in the background of the visual scene move across his/her retina. It, however, is possible to estimate the actual motion of the images despite the eye-movement-induced motion. To understand the neural mechanism that reconstructs a stable visual world independent of eye movements, we explored areas MT (middle temporal) and MST (medial superior temporal) in the monkey cortex, both of which are known to be essential for visual motion analysis. We recorded the responses of neurons to a moving textured image that appeared briefly on the screen while the monkeys were performing smooth pursuit or stationary fixation tasks. Although neurons in both areas exhibited significant responses to the motion of the textured image with directional selectivity, the responses of MST neurons were mostly correlated with the motion of the image on the screen independent of pursuit eye movement, whereas the responses of MT neurons were mostly correlated with the motion of the image on the retina. Thus these MST neurons were more likely than MT neurons to distinguish between external and self-induced motion. The results are consistent with the idea that MST neurons code for visual motion in the external world while compensating for the counter-rotation of retinal images due to pursuit eye movements.

scholarly journals Expectations about motion direction affect perception and anticipatory smooth pursuit differently

2020 ◽  
Author(s):  
Xiuyun Wu ◽  
Austin C. Rothwell ◽  
Miriam Spering ◽  
Anna Montagnini
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Motion Perception ◽  
Smooth Pursuit ◽  
Visual Motion ◽  
Motion Direction ◽  
Visual Motion Perception ◽  
Low Coherence ◽  
Pursuit Eye Movements ◽  
Pursuit Velocity

AbstractSmooth pursuit eye movements and visual motion perception rely on the integration of current sensory signals with past experience. Experience shapes our expectation of current visual events and can drive eye movement responses made in anticipation of a target, such as anticipatory pursuit. Previous research revealed consistent effects of expectation on anticipatory pursuit—eye movements follow the expected target direction or speed—and contrasting effects on motion perception, but most studies considered either eye movement or perceptual responses. The current study directly compared effects of direction expectation on perception and anticipatory pursuit within the same direction discrimination task to investigate whether both types of responses are affected similarly or differently. Observers (n = 10) viewed high-coherence random-dot kinematograms (RDKs) moving rightward and leftward with a probability of 50, 70, or 90% in a given block of trials to build up an expectation of motion direction. They were asked to judge motion direction of interleaved low-coherence RDKs (0-15%). Perceptual judgements were compared to changes in anticipatory pursuit eye movements as a function of probability. Results show that anticipatory pursuit velocity scaled with probability and followed direction expectation (attraction bias), whereas perceptual judgments were biased opposite to direction expectation (repulsion bias). Control experiments suggest that the repulsion bias in perception was not caused by retinal slip induced by anticipatory pursuit, or by motion adaptation. We conclude that direction expectation can be processed differently for perception and anticipatory pursuit.

scholarly journals Neuronal activity in medial superior temporal area (MST) during memory-based smooth pursuit eye movements in monkeys

2011 ◽  
Vol 214 (2) ◽  
pp. 293-301 ◽  
Author(s):  
Sergei Kurkin ◽  
Teppei Akao ◽  
Natsuko Shichinohe ◽  
Junko Fukushima ◽  
Kikuro Fukushima
Keyword(s):  
Eye Movements ◽  
Neuronal Activity ◽  
Smooth Pursuit ◽  
Smooth Pursuit Eye Movements ◽  
Temporal Area ◽  
Pursuit Eye Movements ◽  
Medial Superior Temporal

Contrast and Assimilation in Motion Perception and Smooth Pursuit Eye Movements

2007 ◽  
Vol 98 (3) ◽  
pp. 1355-1363 ◽  
Author(s):  
Miriam Spering ◽  
Karl R. Gegenfurtner
Keyword(s):  
Eye Movements ◽  
Motion Perception ◽  
Smooth Pursuit ◽  
Visual Motion ◽  
Human Motion ◽  
Object Motion ◽  
Velocity Estimation ◽  
Smooth Pursuit Eye Movements ◽  
Pursuit Eye Movements ◽  
Perceived Velocity

The analysis of visual motion serves many different functions ranging from object motion perception to the control of self-motion. The perception of visual motion and the oculomotor tracking of a moving object are known to be closely related and are assumed to be controlled by shared brain areas. We compared perceived velocity and the velocity of smooth pursuit eye movements in human observers in a paradigm that required the segmentation of target object motion from context motion. In each trial, a pursuit target and a visual context were independently perturbed simultaneously to briefly increase or decrease in speed. Observers had to accurately track the target and estimate target speed during the perturbation interval. Here we show that the same motion signals are processed in fundamentally different ways for perception and steady-state smooth pursuit eye movements. For the computation of perceived velocity, motion of the context was subtracted from target motion (motion contrast), whereas pursuit velocity was determined by the motion average (motion assimilation). We conclude that the human motion system uses these computations to optimally accomplish different functions: image segmentation for object motion perception and velocity estimation for the control of smooth pursuit eye movements.

scholarly journals Retinal stabilization reveals limited influence of extraretinal signals on heading tuning in the medial superior temporal area

2019 ◽  
Author(s):  
Tyler S Manning ◽  
Kenneth H Britten
Keyword(s):  
Eye Movements ◽  
Optic Flow ◽  
Theoretical Work ◽  
Efference Copy ◽  
Temporal Area ◽  
Pursuit Eye Movements ◽  
Medial Superior Temporal ◽  
Heading Direction ◽  
Visual Areas ◽  
Self Motion

AbstractHeading perception in primates depends heavily on visual optic-flow cues. Yet during self-motion, heading percepts remain stable even though smooth-pursuit eye movements often distort optic flow. Electrophysiological studies have identified visual areas in monkey cortex, including the dorsal medial superior temporal area (MSTd), that signal the true heading direction during pursuit. According to theoretical work, self-motion can be represented accurately by compensating for these distortions in two ways: via retinal mechanisms or via extraretinal efference-copy signals, which predict the sensory consequences of movement. Psychophysical evidence strongly supports the efference-copy hypothesis, but physiological evidence remains inconclusive. Neurons that signal the true heading direction during pursuit are found in visual areas of monkey cortex, including the dorsal medial superior temporal area (MSTd). Here we measured heading tuning in MSTd using a novel stimulus paradigm, in which we stabilize the optic-flow stimulus on the retina during pursuit. This approach isolates the effects on neuronal heading preferences of extraretinal signals, which remain active while the retinal stimulus is prevented from changing. Our results demonstrate a significant but small influence of extraretinal signals on the preferred heading directions of MSTd neurons. Under our stimulus conditions, which are rich in retinal cues, we find that retinal mechanisms dominate physiological corrections for pursuit eye movements, suggesting that extraretinal cues, such as predictive efference-copy mechanisms, have a limited role under naturalistic conditions.Significance StatementSensory systems discount stimulation caused by the animal’s own behavior. For example, eye movements cause irrelevant retinal signals that could interfere with motion perception. The visual system compensates for such self-generated motion, but how this happens is unclear. Two theoretical possibilities are a purely visual calculation or one using an internal signal of eye movements to compensate for their effects. Such a signal can be isolated by experimentally stabilizing the image on a moving retina, but this approach has never been adopted to study motion physiology. Using this method, we find that eye-movement signals have little influence on neural activity in visual cortex, while feed-forward visual calculation has a strong effect and is likely important under real-world conditions.

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