Perceived Visual Motion as Effective Stimulus to Pursuit Eye Movement System

Yasui, Syozo; Young, Laurence R.

doi:10.1126/science.1188373

Cited by 350 publications

(74 citation statements)

References 14 publications

(3 reference statements)

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“…The oculomotor results are consistent with the conclusion of Yasui and Young (1975) that efference copy gains are less than 1; they also point out that gain adaptation makes these values vary according to stimulus conditions. In studies of smooth pursuit tracking they find evidence that the efference copy is active even under normal closed-loop conditions, not only during saccades.…”

Section: Discussionsupporting

confidence: 79%

Effect of context and efference copy on visual straight ahead

Bridgeman

Graziano

1989

Vision Research

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Abstract-Biasin efferent commands to the eye changes the apparent straight ahead direction in an unstructured visual field, but has little effect in a normal visual environment. Naive subjects set a visible marker to appear straight ahead under monocular viewing conditions and while pressing on the viewing eye. Three background conditions were used: a naturalistic landscape photograph, a blank field, and a repeating checkerboard texture that provides strong contours but no information about visual direction.Effect of eyepress on straight-ahead judgments was small but significant with the landscape back8round, and larger with the blank field; the checkerboard texture yielded a bias halfway between the maguitudes of bias in the other two conditions. A visual capture theory predicts that the textured field should work like a blank one, while an oculomotor theory predicts that it should work like a natural one. Interpreted in this context, the results show the two theories to be about equally important in judging straight ahead. A second experiment with experienced observers and moving backgrounds gave the same result.

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Section: Discussionsupporting

confidence: 79%

Effect of context and efference copy on visual straight ahead

Bridgeman

Graziano

1989

Vision Research

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“…However, a high feedback gain together with the inevitable neural delays in the loop (the retina alone is assumed to delay the visual signal by 20-40 ms) would cause the system to become instable. As suggested by Yasui and Young (1975), instead of using highly amplified retinal slip as drive for pursuit, target velocity may be internally reconstructed by using an efference copy of the motor output, and utilize this estimate of target velocity as drive. Robinson et al (1986) showed that such a scheme also allows to overcome the delay problem.…”

Section: Smooth Pursuit (Sp)mentioning

confidence: 99%

A model-based theory on the origin of downbeat nystagmus

et al. 2008

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A model-based theory on the origin of downbeat nystagmus AbstractThe pathomechanism of downbeat nystagmus (DBN), an ocular motor sign typical for vestibulo-cerebellar lesions, remains unclear. Previous hypotheses conjectured various deficits such as an imbalance of central vertical vestibular or smooth pursuit pathways to be causative for the generation of spontaneous upward drift. However, none of the previous theories explains the full range of ocular motor deficits associated with DBN, i.e., impaired vertical smooth pursuit (SP), gaze evoked nystagmus, and gravity dependence of the upward drift. We propose a new hypothesis, which explains the ocular motor signs of DBN by damage of the inhibitory vertical gaze-velocity sensitive Purkinje cells (PCs) in the cerebellar flocculus (FL). These PCs show spontaneous activity and a physiological asymmetry in that most of them exhibit downward on-directions. Accordingly, a loss of vertical floccular PCs will lead to disinhibition of their brainstem target neurons and, consequently, to spontaneous upward drift, i.e., DBN. Since the FL is involved in generation and control of SP and gaze holding, a single lesion, e.g., damage to vertical floccular PCs, may also explain the associated ocular motor deficits. To test our hypothesis, we developed a computational model of vertical eye movements based on known ocular motor anatomy and physiology, which illustrates how cortical, cerebellar, and brainstem regions interact to generate the range of vertical eye movements seen in healthy subjects. Model simulation of the effect of extensive loss of floccular PCs resulted in ocular motor features typically associated with cerebellar DBN: (1) spontaneous upward drift due to decreased spontaneous PC activity, (2) gaze evoked nystagmus corresponding to failure of the cerebellar loop supporting neural integrator function, (3) asymmetric vertical SP deficit due to low gain and asymmetric attenuation of PC firing, and (4) gravity-dependence of DBN caused by an interaction of otolith-ocular pathways with impaired neural integrator function.

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“…The models of Yasui and Young (1975) and Young (1981) added a corollary discharge pathway to give eye position information to the smooth pursuit system. We have also included a pathway providing eye position information.…”

Section: Relationship Of Present Model To Previous Modelsmentioning

confidence: 99%

“…We know of no other physically realizable model or man-made system that can do this. Previous studies of the predictive capabilities of the smooth pursuit eye movement system have been analysis only Stark etal., 1962;Dallos and Jones, 1963;Michael and Melvile Jones, 1966;Steinbach, 1976;Lanman et al, 1978;Winterson and Steinman, 1978;Scbalen, 1980;Eckmiller, 1981 cally unrealizable models (Dallos and Jones, 1963), or have produced models that did not track the target with zero-latency (Greene and Ward, 1979 ;Yasui and Young, 1975). Among physiological time-delay systems only the saccadic and smooth pursuit eye movement systems exhibit zero-latency tracking; manual tracking systems (McRuer, 1980;Kleinman etal., 1980) and even the vergence eye movement system fail to show prediction (Rashbass, 1981).…”

Section: Introductionmentioning

confidence: 99%

“…It is as if the subject creates an internal model of the target movement and uses this model to help track the target. This internal model has variously been called a predictor Stark et al, 1962), a long term learning process (Dallos and Jones, 1963), a percept tracker (Yasui and Young, 1975;Young, 1977;Steinbach, 1976;Mack et al, 1982), a neutral motor pattern generator (Eckmiller, 1981), and a target-selective adaptive controller (McDonald and Bahill, 1983). To help explain how the human performs such zero-latency tracking, we developed a model that does the same.…”

Section: Introductionmentioning

confidence: 99%

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Model emulates human smooth pursuit system producing zero-latency target tracking

1983

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Abstract. Humans can overcome the 150 ms time delay of the smooth pursuit eye movement system and track smoothly moving visual targets with zero-latency. Our target-selective adaptive control model can also overcome an inherent time delay and produce zero-latency tracking. No other model or man-made system can do this. Our model is physically realizable and physiologically realistic. The technique used in our model should be useful for analyzing other time-delay systems, such as man-machine systems and robots.

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Perceived Visual Motion as Effective Stimulus to Pursuit Eye Movement System

Cited by 350 publications

References 14 publications

Effect of context and efference copy on visual straight ahead

Effect of context and efference copy on visual straight ahead

A model-based theory on the origin of downbeat nystagmus

Model emulates human smooth pursuit system producing zero-latency target tracking

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