scholarly journals Visual straight-ahead preference in saccadic eye movements

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Damien Camors ◽  
Yves Trotter ◽  
Pierre Pouget ◽  
Sophie Gilardeau ◽  
Jean-Baptiste Durand
1998 ◽  
Vol 79 (6) ◽  
pp. 2895-2902 ◽  
Author(s):  
Klaus G. Rottach ◽  
Vallabh E. Das ◽  
Walter Wohlgemuth ◽  
Ari Z. Zivotofsky ◽  
R. John Leigh

Rottach, Klaus G., Vallabh E. Das, Walter Wohlgemuth, Ari Z. Zivotofsky, and R. John Leigh. Properties of horizontal saccades accompanied by blinks. J. Neurophysiol. 79: 2895–2902, 1998. Using the magnetic search coil technique to record eye and lid movements, we investigated the effect of voluntary blinks on horizontal saccades in five normal human subjects. The main goal of the study was to determine whether changes in the dynamics of saccades with blinks could be accounted for by a superposition of the eye movements induced by blinks as subjects fixated a stationary target and saccadic movements made without a blink. First, subjects made voluntary blinks as they fixed on stationary targets located straight ahead or 20° to the right or left. They then made saccades between two continuously visible targets 20 or 40° apart, while either attempting not to blink, or voluntarily blinking, with each saccade. During fixation of a target located straight ahead, blinks induced brief downward and nasalward deflections of eye position. When subjects looked at targets located at right or left 20°, similar initial movements were made by four of the subjects, but the amplitude of the adducted eye was reduced by 65% and was followed by a larger temporalward movement. Blinks caused substantial changes in the dynamic properties of saccades. For 20° saccades made with blinks, peak velocity and peak acceleration were decreased by ∼20% in all subjects compared with saccades made without blinks. Blinks caused the duration of 20° saccades to increase, on average, by 36%. On the other hand, blinks had only small effects on the gain of saccades. Blinks had little influence on the relative velocities of centrifugal versus centripetal saccades, and abducting versus adducting saccades. Three of five subjects showed a significantly increased incidence of dynamic overshoot in saccades accompanied by blinks, especially for 20° movements. Taken with other evidence, this finding suggests that saccadic omnipause neurons are inhibited by blinks, which have longer duration than the saccades that company them. In conclusion, the changes in dynamic properties of saccades brought about by blinks cannot be accounted for simply by a summation of gaze perturbations produced by blinks during fixation and saccadic eye movements made without blinks. Our findings, especially the appearance of dynamic overshoots, suggest that blinks affect the central programming of saccades. These effects of blinks need to be taken into account during studies of the dynamic properties of saccades.


2000 ◽  
Vol 83 (6) ◽  
pp. 3411-3429 ◽  
Author(s):  
H.H.L.M. Goossens ◽  
A. J. Van Opstal

Saccadic eye movements are thought to be influenced by blinking through premotor interactions, but it is still unclear how. The present paper describes the properties of blink-associated eye movements and quantifies the effect of reflex blinks on the latencies, metrics, and kinematics of saccades in the monkey. In particular, it is examined to what extent the saccadic system accounts for blink-related perturbations of the saccade trajectory. Trigeminal reflex blinks were elicited near the onset of visually evoked saccades by means of air puffs directed on the eye. Reflex blinks were also evoked during a straight-ahead fixation task. Eye and eyelid movements were measured with the magnetic-induction technique. The data show that saccade latencies were reduced substantially when reflex blinks were evoked prior to the impending visual saccades as if these saccades were triggered by the blink. The evoked blinks also caused profound spatial-temporal perturbations of the saccades. Deflections of the saccade trajectory, usually upward, extended up to ∼15°. Saccade peak velocities were reduced, and a two- to threefold increase in saccade duration was typically observed. In general, these perturbations were largely compensated in saccade mid-flight, despite the absence of visual feedback, yielding near-normal endpoint accuracies. Further analysis revealed that blink-perturbed saccades could not be described as a linear superposition of a pure blink-associated eye movement and an unperturbed saccade. When evoked during straight-ahead fixation, blinks were accompanied by initially upward and slightly abducting eye rotations of ∼2–15°. Back and forth wiggles of the eye were frequently seen; but in many cases the return movement was incomplete. Rather than drifting back to its starting position, the eye then maintained its eccentric orbital position until a downward corrective saccade toward the fixation spot followed. Blink-associated eye movements were quite rapid, albeit slower than saccades, and the velocity-amplitude-duration characteristics of the initial excursions as well as the return movements were approximately linear. These data strongly support the idea that blinks interfere with the saccade premotor circuit, presumably upstream from the neural eye-position integrator. They also indicated that a neural mechanism, rather than passive elastic restoring forces within the oculomotor plant, underlies the compensatory behavior. The tight latency coupling between saccades and blinks is consistent with an inhibition of omnipause neurons by the blink system, suggesting that the observed changes in saccade kinematics arise elsewhere in the saccadic premotor system.


2013 ◽  
Author(s):  
Sara Spotorno ◽  
Guillaume S. Masson ◽  
Anna Montagnini

2000 ◽  
Vol 132 (1) ◽  
pp. 39-51 ◽  
Author(s):  
Christian Quaia ◽  
Martin Paré ◽  
Robert H. Wurtz ◽  
Lance M. Optican

Healthcare ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 10
Author(s):  
Chong-Bin Tsai ◽  
Wei-Yu Hung ◽  
Wei-Yen Hsu

Optokinetic nystagmus (OKN) is an involuntary eye movement induced by motion of a large proportion of the visual field. It consists of a “slow phase (SP)” with eye movements in the same direction as the movement of the pattern and a “fast phase (FP)” with saccadic eye movements in the opposite direction. Study of OKN can reveal valuable information in ophthalmology, neurology and psychology. However, the current commercially available high-resolution and research-grade eye tracker is usually expensive. Methods & Results: We developed a novel fast and effective system combined with a low-cost eye tracking device to accurately quantitatively measure OKN eye movement. Conclusions: The experimental results indicate that the proposed method achieves fast and promising results in comparisons with several traditional approaches.


Author(s):  
Christian Wolf ◽  
Markus Lappe

AbstractHumans and other primates are equipped with a foveated visual system. As a consequence, we reorient our fovea to objects and targets in the visual field that are conspicuous or that we consider relevant or worth looking at. These reorientations are achieved by means of saccadic eye movements. Where we saccade to depends on various low-level factors such as a targets’ luminance but also crucially on high-level factors like the expected reward or a targets’ relevance for perception and subsequent behavior. Here, we review recent findings how the control of saccadic eye movements is influenced by higher-level cognitive processes. We first describe the pathways by which cognitive contributions can influence the neural oculomotor circuit. Second, we summarize what saccade parameters reveal about cognitive mechanisms, particularly saccade latencies, saccade kinematics and changes in saccade gain. Finally, we review findings on what renders a saccade target valuable, as reflected in oculomotor behavior. We emphasize that foveal vision of the target after the saccade can constitute an internal reward for the visual system and that this is reflected in oculomotor dynamics that serve to quickly and accurately provide detailed foveal vision of relevant targets in the visual field.


2021 ◽  
Author(s):  
Federico Carbone ◽  
Philipp Ellmerer ◽  
Marcel Ritter ◽  
Sabine Spielberger ◽  
Philipp Mahlknecht ◽  
...  

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