Target Selection by the Frontal Cortex during Coordinated Saccadic and Smooth Pursuit Eye Movements

2009 ◽  
Vol 21 (8) ◽  
pp. 1611-1627 ◽  
Author(s):  
Krishna Srihasam ◽  
Daniel Bullock ◽  
Stephen Grossberg
Keyword(s):  
Eye Movements ◽  
Smooth Pursuit ◽  
Current Model ◽  
Target Selection ◽  
Motion Processing ◽  
Parallel Model ◽  
Smooth Pursuit Eye Movements ◽  
Pontine Nucleus ◽  
Temporal Area ◽  
Pursuit Eye Movements

Oculomotor tracking of moving objects is an important component of visually based cognition and planning. Such tracking is achieved by a combination of saccades and smooth-pursuit eye movements. In particular, the saccadic and smooth-pursuit systems interact to often choose the same target, and to maximize its visibility through time. How do multiple brain regions interact, including frontal cortical areas, to decide the choice of a target among several competing moving stimuli? How is target selection information that is created by a bias (e.g., electrical stimulation) transferred from one movement system to another? These saccade–pursuit interactions are clarified by a new computational neural model, which describes interactions between motion processing areas: the middle temporal area, the middle superior temporal area, the frontal pursuit area, and the dorsal lateral pontine nucleus; saccade specification, selection, and planning areas: the lateral intraparietal area, the frontal eye fields, the substantia nigra pars reticulata, and the superior colliculus; the saccadic generator in the brain stem; and the cerebellum. Model simulations explain a broad range of neuroanatomical and neurophysiological data. These results are in contrast with the simplest parallel model with no interactions between saccades and pursuit other than common-target selection and recruitment of shared motoneurons. Actual tracking episodes in primates reveal multiple systematic deviations from predictions of the simplest parallel model, which are explained by the current model.

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.

Response properties of dorsolateral pontine units during smooth pursuit in the rhesus macaque

1988 ◽  
Vol 60 (2) ◽  
pp. 664-686 ◽  
Author(s):  
M. J. Mustari ◽  
A. F. Fuchs ◽  
J. Wallman
Keyword(s):  
Eye Movements ◽  
Smooth Pursuit ◽  
Visual Sensitivity ◽  
Large Field ◽  
Motion Processing ◽  
Smooth Pursuit Eye Movements ◽  
Pontine Nucleus ◽  
Stimulus Velocity ◽  
Pursuit Eye Movements ◽  
Visual Motion Processing

1. The anatomical connections of the dorsolateral pontine nucleus (DLPN) implicate it in the production of smooth-pursuit eye movements. It receives inputs from cortical structures believed to be involved in visual motion processing (middle temporal cortex) or motion execution (posterior parietal cortex) and projects to the flocculus of the cerebellum, which is involved in smooth pursuit. To determine the role of the DLPN in smooth pursuit, we have studied the discharge patterns of 191 DLPN neurons in five monkeys trained to make smooth-pursuit eye movements of a spot moving either across a patterned background or in darkness. 2. Four unit types could be distinguished. Visual units (15%) discharged in response to movement of a large textured pattern, often in a direction-selective fashion but not during smooth pursuit of a spot in the dark. Eye movement neurons (31%) discharged during sinusoidal smooth pursuit in the dark with peak discharge rate either at peak eye position or peak eye velocity, but they showed no response during background movement or during other visual stimulation. These units continued to discharge when the target was extinguished (blanked) briefly, and the monkey continued to make smooth eye movements in the dark. The majority (54%) of our DLPN units discharged during both smooth pursuit in the dark and background movement while the monkey fixated. Blanking the target during smooth pursuit revealed that these units fell into two distinct classes. Visual pursuit units ceased discharging during a blank, suggesting that they had only a visual sensitivity. Pursuit and visual units continued to discharge during the blank, indicating that they had a combined oculomotor and visual sensitivity. 3. Ninety-five percent of the units that discharged during smooth pursuit were direction selective. These units had rather broad directional tuning curves with widths at half height ranging from 65 to 180 degrees. Many preferred directions for DLPN units were observed, although the vertical and near-vertical directions predominated. 4. Most units that responded to large-field background movement were direction selective. During sinusoidal movement of a large-field background, half of them also discharged in relation to stimulus velocity, whereas others did not.

Smooth-Pursuit Eye-Movement Deficits With Chemical Lesions in Macaque Nucleus Reticularis Tegmenti Pontis

1999 ◽  
Vol 82 (3) ◽  
pp. 1178-1186 ◽  
Author(s):  
David A. Suzuki ◽  
Tetsuto Yamada ◽  
Rebecca Hoedema ◽  
Robert D. Yee
Keyword(s):  
Eye Movements ◽  
Smooth Pursuit ◽  
Ibotenic Acid ◽  
Frontal Eye Field ◽  
Smooth Pursuit Eye Movements ◽  
Pontine Nucleus ◽  
Nucleus Reticularis Tegmenti Pontis ◽  
Pursuit Eye Movements ◽  
Nucleus Reticularis ◽  
Dorsolateral Pontine Nucleus

Anatomic and neuronal recordings suggest that the nucleus reticularis tegmenti pontis (NRTP) of macaques may be a major pontine component of a cortico-ponto-cerebellar pathway that subserves the control of smooth-pursuit eye movements. The existence of such a pathway was implicated by the lack of permanent pursuit impairment after bilateral lesions in the dorsolateral pontine nucleus. To provide more direct evidence that NRTP is involved with regulating smooth-pursuit eye movements, chemical lesions were made in macaque NRTP by injecting either lidocaine or ibotenic acid. Injection sites first were identified by the recording of smooth-pursuit-related modulations in neuronal activity. The resulting lesions caused significant deficits in both the maintenance and the initiation of smooth-pursuit eye movements. After lesion formation, the gain of constant-velocity, maintained smooth-pursuit eye movements decreased, on the average, by 44%. Recovery of the ability to maintain smooth-pursuit eye movements occurred over ∼3 days when maintained pursuit gains attained normal values. The step-ramp, “Rashbass” task was used to investigate the effects of the lesions on the initiation of smooth-pursuit eye movements. Eye accelerations averaged over the initial 80 ms of pursuit initiation were determined and found to be decremented, on the average, by 48% after the administration of ibotenic acid. Impairments in the initiation and maintenance of smooth-pursuit eye movements were directional in nature. Upward pursuit seemed to be the most vulnerable and was impaired in all cases independent of lesioning agent and type of pursuit investigated. Downward smooth pursuit seemed more resistant to the effects of chemical lesions in NRTP. Impairments in horizontal tracking were observed with examples of deficits in ipsilaterally and contralaterally directed pursuit. The results provide behavioral support for the physiologically and anatomic-based conclusion that NRTP is a component of a cortico-ponto-cerebellar circuit that presumably involves the pursuit area of the frontal eye field (FEF) and projects to ocular motor-related areas of the cerebellum. This FEF-NRTP-cerebellum path would parallel a middle and medial superior temporal cerebral cortical area-dorsolateral pontine nucleus-cerebellum pathway also known to be involved with regulating smooth-pursuit eye movements.

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.

Target selection for predictive smooth pursuit eye movements

2004 ◽  
Vol 155 (1) ◽  
pp. 129-133 ◽  
Author(s):  
E. Poliakoff ◽  
C. J. S. Collins ◽  
G. R. Barnes
Keyword(s):  
Eye Movements ◽  
Smooth Pursuit ◽  
Target Selection ◽  
Smooth Pursuit Eye Movements ◽  
Pursuit Eye Movements ◽  
Selection For

Smooth pursuitlike eye movements evoked by microstimulation in macaque nucleus reticularis tegmenti pontis

1996 ◽  
Vol 76 (5) ◽  
pp. 3313-3324 ◽  
Author(s):  
T. Yamada ◽  
D. A. Suzuki ◽  
R. D. Yee
Keyword(s):  
Eye Movements ◽  
Smooth Pursuit ◽  
Current Intensity ◽  
Image Motion ◽  
Eye Position ◽  
Smooth Pursuit Eye Movements ◽  
Pontine Nucleus ◽  
Nucleus Reticularis Tegmenti Pontis ◽  
Pursuit Eye Movements ◽  
Nucleus Reticularis

1. Smooth pursuitlike eye movements were evoked with low current microstimulation delivered to rostral portions of the nucleus reticularis tegmenti pontis (rNRTP) in alert macaques. Microstimulation sites were selected by the observation of modulations in single-cell firing rates that were correlated with periodic smoothpursuit eye movements. Current intensities ranged from 10 to 120 microA and were routinely < 40 microA. Microstimulation was delivered either in the dark with no fixation, 100 ms after a fixation target was extinguished, or during maintained fixation of a stationary or moving target. Evoked eye movements also were studied under open-loop conditions with the target image stabilized on the retina. 2. Eye movements evoked in the absence of a target rapidly accelerated to a constant velocity that was maintained for the duration of the microstimulation. Evoked eye speeds ranged from 3.7 to 23 deg/s and averaged 11 deg/s. Evoked eye speed appeared to be linearly related to initial eye position with a sensitivity to initial eye position that averaged 0.23 deg.s-1.deg-1. While some horizontal and oblique smooth eye movements were elicited, microstimulation resulted in upward eye movements in 89% of the sites. 3. Evoked eye speed was found to be dependent on microstimulation pulse frequency and current intensity. Within limits, evoked eye speed increased with increases in stimulation frequency or current intensity. For stimulation frequencies < 300–400 Hz, only smooth pursuit-like eye movements were evoked. At higher stimulation frequencies, accompanying saccades consistently were elicited. 4. Feedback of retinal image motion interacted with the evoked eye movements to decrease eye speed if the visual motion was in the opposite direction as the evoked, pursuit-like eye movements. 5. The results implicate rNRTP as part of the neuronal substrate that controls smooth-pursuit eye movements. NRTP appears to be divided functionally into a rostral, pursuit-related portion and a caudal, saccade-related area. rNRTP is a component of a corticopontocerebellar circuit that presumably involves the pursuit area of the frontal eye field and that parallels the middle and medial superior temporal cerebral cortical/dorsalateral pontine nucleus (MT/MST-DLPN-cerebellum) pathway known to be involved also with regulating smooth-pursuit eye movements.

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.

Smooth-pursuit eye movement deficits with chemical lesions in the dorsolateral pontine nucleus of the monkey

1988 ◽  
Vol 59 (3) ◽  
pp. 952-977 ◽  
Author(s):  
J. G. May ◽  
E. L. Keller ◽  
D. A. Suzuki
Keyword(s):  
Steady State ◽  
Eye Movements ◽  
Smooth Pursuit ◽  
Visual Motion ◽  
Ibotenic Acid ◽  
Smooth Pursuit Eye Movements ◽  
Optokinetic Response ◽  
Pontine Nucleus ◽  
Pursuit Eye Movements ◽  
Dorsolateral Pontine Nucleus

1. Anatomical and single-unit recording studies suggest that the dorsolateral pontine nucleus (DLPN) in monkey is a major link in the projection of descending visual motion information to the cerebellum. Such studies coupled with cortical and cerebellar lesion results suggest a major role for this basilar pontine region in the mediation of smooth-pursuit eye movements. 2. To provide more direct evidence that this pontine region is involved in the control of smooth-pursuit eye movements, focal chemical lesions were made in DLPN in the vicinity of previously recorded visual motion and pursuit-related neurons. Eye movement responses were subsequently recorded in these lesioned animals under several behavioral paradigms. 3. A major deficit in smooth-pursuit performance was produced after unilateral DLPN lesions generated either reversibly with lidocaine or more permanently with ibotenic acid. Pursuit impairments were observed during steady-state tracking of sinusoidal target motion as well as during the initiation of pursuit tracking to sudden ramp target motion. Through the use of the latter technique, initial eye acceleration was reduced to less than one-half of normal for animals with large lesions of the dorsolateral and lateral pontine nuclei. 4. The pursuit deficit in all animals was directional in nature and was not dependent on the visual hemifield in which the motion stimulus occurred. The largest effect for horizontal tracking occurred in all animals for pursuit directed ipsilateral to the lesion. Animals also showed major deficits in one or both directions of vertical pursuit, although the primary direction of the vertical impairment was variable from animal to animal. 5. Chemical lesions in the DLPN also produced comparable deficits in the initiation of optokinetic-induced smooth eye movements in the ipsilateral direction. In contrast to this effect on the initial optokinetic response, in the one lesioned animal studied during prolonged constant velocity optokinetic drum rotation, smooth eye speed increased slowly over a 10- to 15-s period to reach a level that closely matched drum speed. These results suggest that pathways outside the DLPN can generate the steady-state optokinetic response. 6. Saccades to stationary targets were normal after DLPN lesions, but corrective saccades made to targets moving in the direction ipsilateral to the lesion were much more hypometric than similar prelesion control saccades. 7. The pursuit deficits produced by lidocaine injections recovered within 30 min. The ibotenic acid deficits were maximal approximately 1 day after the injection and recovered rapidly thereafter over a time period of 3-7 days.(ABSTRACT TRUNCATED AT 400 WORDS)

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