Head-fixed saccades can have amplitudes of up to 90° (from one edge of the oculomotor range to the other), but in normal conditions saccades are far smaller, and any shift of gaze larger than about 20° is accompanied by a headmovement. (wikipedia.org)
Here, we show that the magnitude of perceptual compression for a wide variety of probe stimuli and saccade amplitudes is quantitatively predicted by a simple heuristic model based on the geometry of retinotopic representations in the primate brain. (jneurosci.org)
Stimuli2
This differential enhancement is only significant after observers are instructed which cue to attend, but before the acoustic stimuli begin. (frontiersin.org)
For humans, visual tracking of moving stimuli often triggers catch-up saccades during smooth pursuit. (eneuro.org)
Saccadic3
citation needed] When scanning immediate surroundings or reading, human eyes make saccadic movements and stop several times, moving very quickly between each stop. (wikipedia.org)
The switch between these continuous and discrete eye movements is a trade-off between tolerating sustained position error (PE) when no saccade is triggered or a transient loss of vision during the saccade due to saccadic suppression. (eneuro.org)
Informed by model predictions, we hypothesized that saccade trigger time length and variability will increase when pre-saccadic predicted errors are small or visual uncertainty is high (e.g., for blurred targets). (eneuro.org)
Gaze2
Saccades may rotate the eyes in any direction to relocate gaze direction (the direction of sight that corresponds to the fovea), but normally saccades do not rotate the eyes torsionally. (wikipedia.org)
During such gaze saccades, first, the eye produces a saccade to get gaze on target, whereas the head follows more slowly and the vestibulo-ocular reflex (VOR) causes the eyes to roll back in the head to keep gaze on the target. (wikipedia.org)
Oculomotor2
Under this assumption, the psychophysical data on perisaccadic compression can be appreciated intuitively by imagining that, around the time of a saccade, the brain confounds nearby oculomotor and sensory signals while attempting to localize the position of objects in visual space. (jneurosci.org)
Furthermore, by linking motor control to statistical decision-making, we offer a novel perspective on how sensorimotor prediction and uncertainty modulate oculomotor tracking behavior. (eneuro.org)
Transient2
Specific pre-target oscillatory (alpha rhythms) and transient activities occurring in posterior-lateral parietal cortex and occipital cortex also characterise express saccades. (wikipedia.org)
Saccades can be categorized by intended goal in four ways: In a visually guided saccade, the eyes move toward a visual transient, or stimulus. (wikipedia.org)
Velocity2
Velocity-based algorithms are a common approach for saccade detection in eye tracking. (wikipedia.org)
Thus, accurate tracking requires a synergistic coordination of saccades and smooth pursuit eye movements to overcome retinal position and velocity mismatches, respectively. (eneuro.org)
Pursuit7
The high peak velocities and the main sequence relationship can also be used to distinguish micro-/saccades from other eye movements (like ocular tremor, ocular drift, and smooth pursuit). (wikipedia.org)
In summary, our data supports our hypothesized predicted error-based decision process for coordinating saccades during smooth pursuit. (eneuro.org)
The mechanism by which the brain decides when to trigger discrete catch-up saccades during continuous smooth pursuit has eluded researchers for decades. (eneuro.org)
Our results add support for a common and shared sensorimotor process for saccades and pursuit. (eneuro.org)
For a long time, it was believed that saccades and smooth pursuit were controlled by independent functional and anatomic systems in the brain ( Robinson, 1986 ). (eneuro.org)
As a consequence, the properties of saccades and smooth pursuit were studied independently. (eneuro.org)
Consequently, our current understanding describes saccades and pursuit as two outcomes of a synergistic sensorimotor process, sharing sensory inputs, anatomic pathways, and functional regulation ( Orban de Xivry and Lefèvre, 2007 ). (eneuro.org)
Movements1
Saccades are one of the fastest movements produced by the human eye (blinks may reach even higher peak velocities). (wikipedia.org)
Predictions1
Importantly, because our model can be characterized by a simple closed-form expression, it also makes specific predictions about the outcome of future psychophysical experiments and the characteristics of brain structures that might be involved in perceptual estimates of the metrics of visual space. (jneurosci.org)
Target2
demonstrated that catch-up saccades were less likely to occur when the target re-crosses the fovea within 40-180 ms. To date, there is no mechanistic explanation for how the trigger decision is made by the brain. (eneuro.org)
When significant position error (PE) is accumulated, a catch-up saccade may be triggered to re-foveate the target. (eneuro.org)
Mechanism2
Controlled cortically by the frontal eye fields (FEF), or subcortically by the superior colliculus, saccades serve as a mechanism for fixation, rapid eye movement, and the fast phase of optokinetic nystagmus. (wikipedia.org)
These saccades are generated by a neuronal mechanism that bypasses time-consuming circuits and activates the eye muscles more directly. (wikipedia.org)
Visual1
Specifically, we propose that perisaccadic compression is determined by the distance between the probe and saccade end point on a map that has a logarithmic representation of visual space, similar to those found in numerous cortical and subcortical visual structures. (jneurosci.org)
Direction1
A saccade (/səˈkɑːd/ sə-KAHD, French for jerk) is a quick, simultaneous movement of both eyes between two or more phases of fixation in the same direction. (wikipedia.org)
Time2
Under certain laboratory circumstances, the latency of, or reaction time to, saccade production can be cut nearly in half (express saccades). (wikipedia.org)
Eye tracking assessments can be simple for clinicians to administer, and most can report real-time illustrative graphics, making it easy to communicate results to patients and improve the understanding of their diagnoses. (todaysgeriatricmedicine.com)
Position1
Likewise, saccades and their properties were thought to be strictly governed by position inputs ( Wurtz and Optican, 1994 ). (eneuro.org)
Fovea2
Saccades may rotate the eyes in any direction to relocate gaze direction (the direction of sight that corresponds to the fovea), but normally saccades do not rotate the eyes torsionally. (wikipedia.org)
In a methodologically sophisticated study of pre-saccadic processing at the fovea, Kroell and Rolfs provide compelling evidence that saccade preparation causes feature-specific pre-saccadic visual enhancement restricted largely to the center of gaze. (elifesciences.org)
Amplitude2
Saccades to an unexpected stimulus normally take about 200 milliseconds (ms) to initiate, and then last from about 20-200 ms, depending on their amplitude (20-30 ms is typical in language reading). (wikipedia.org)
The amplitude of a saccade is the angular distance the eye travels during the movement. (wikipedia.org)
Fixation4
A saccade (/səˈkɑːd/ sə-KAHD, French for jerk) is a quick, simultaneous movement of both eyes between two or more phases of fixation in the same direction. (wikipedia.org)
Controlled cortically by the frontal eye fields (FEF), or subcortically by the superior colliculus, saccades serve as a mechanism for fixation, rapid eye movement, and the fast phase of optokinetic nystagmus. (wikipedia.org)
Based on findings from passive fixation tasks, we hypothesized that during saccade preparation, foveal processing anticipates soon-to-be fixated visual features. (elifesciences.org)
Moreover, foveal enhancement during saccade preparation was more pronounced and developed faster than enhancement during passive fixation. (elifesciences.org)
Movement3
instead, the eyes move around, locating interesting parts of the scene and building up a mental, three-dimensional 'map' corresponding to the scene (as opposed to the graphical map of avians, that often relies upon detection of angular movement on the retina). (wikipedia.org)
Baseball players could achieve high DVA with significantly faster eye movement at shorter latencies than nonplayers. (medscape.com)
Bahill and Laritz [ 5 ] suggested that major league baseball players make anticipatory saccades when dealing with balls traveling faster than the upper limit of eye movement as the ball approaches the batter's box. (medscape.com)
Larger1
The absolute value of the interocular delay was found to be larger in the myopic and anisomyopic observers than that of the emmetropic controls at 1 and 2 c/deg when there was no optical correction. (psych.ac.cn)
Model4
We build a random forest regressor model to predict the attention and impulsivity scales' total score. (bvsalud.org)
Results showed that cerebellar pathology restrains short-term recalibration of the inverse model while the forward dynamics model is well informed about the reduced saccade change. (bvsalud.org)
We conclude that the cerebellum mediates short-term adaptation of the inverse model, especially by control of saccade duration, while the forward dynamics model was not affected by cerebellar pathology. (bvsalud.org)
Then we built a receptive field model based on retinotopic information processing to simulate neuronal responses. (psych.ac.cn)
Study1
Major advances in the study of gyrate atrophy have been made by a team of scientists led by Dr. Muriel Kaiser-Kupfer. (nih.gov)