Loading...
  • fixation
  • We compared the effects of gazing at a fixation point (FP) and performing saccades (SAC) on various spatial and temporal measures of the center of pressure (CoP) while participants stood as still as possible on a force plate. (springer.com)
  • In the presence of a peripheral vestibular deficit, the eyes move with the head and a "catch-up" saccade is required to bring gaze back toward the fixation target ( 2 ). (frontiersin.org)
  • Observers compared orientation and contrast of a test stimulus, appearing briefly before a saccade, to a standard stimulus, presented previously during a fixation period. (jneurosci.org)
  • In this study, to assess effects of saccade preparation, we asked observers to simultaneously judge both the orientation and the contrast of a test stimulus presented at the target of a cued saccadic eye movement relative to a standard stimulus shown during prior fixation ( Fig. 1 ). (jneurosci.org)
  • Monkeys were trained on a pro-/anti-saccade paradigm in which they either had to generate a pro-saccade toward a visual stimulus or an anti-saccade away from the stimulus to its mirror position, depending on the color of an initial fixation point. (jneurosci.org)
  • On anti-saccade trials, fixation during the instruction period was associated with an increased activity of collicular fixation-related neurons and a decreased activity of saccade-related neurons. (jneurosci.org)
  • Blinks, Saccades, and Fixation Pauses During Vigilance Task Performance: 1. (dtic.mil)
  • SUPERIOR COLLICULUS
  • As a first step to identify the pathway that transmits the error signal for motor learning in saccades, we investigated the effect of local microstimulation in the medial part of the mesencephalic tegmentum, a region that contains fibers from two candidate structures that instruct the cerebellum, superior colliculus, and parvocellular red nucleus. (jneurosci.org)
  • Neural activity was recorded in the superior colliculus (SC), a structure that is known to be involved in the generation of fast saccades, to determine whether it was also involved in the generation of anti-saccades. (jneurosci.org)
  • paradigm
  • In a paradigm in which a target on the horizontal meridian jumped vertically during the saccade (resulting in an endpoint error), the adaptive response exhibited two timescales: a fast timescale that learned quickly from endpoint error but had poor retention, and a slow timescale that learned slowly but had strong retention. (jneurosci.org)
  • To this end, we adapted a gaze correction paradigm in which a saccade was executed toward either a previously fixated or a novel target. (springer.com)
  • In this paradigm, participants made a saccade toward one of 12 colored disks. (springer.com)
  • neural
  • A neural network model of biophysical neurons in the midbrain is presented to drive a muscle fiber oculomotor plant during horizontal monkey saccades. (hindawi.com)
  • It is concluded that the neural network is constrained by a minimum duration of the agonist pulse and that the most dominant factor in determining the saccade magnitude is the number of active neurons for the small saccades. (hindawi.com)
  • The saccade neural network requires involvement of a series of neurons designed to imitate the behavior of actual neuronal populations in the horizontal saccade controller. (hindawi.com)
  • Taking advantage of the directional specificity of saccade adaptation, we further show that microstimulation creates signals that are equivalent to the neural correlate of visual error in two-dimensional space. (jneurosci.org)
  • Here we reveal this missing link by showing that saccade preparation increases the perceived signal strength-perceived contrast-consistent with enhanced neural representations of visual information at the saccade target. (jneurosci.org)
  • midbrain
  • Our findings suggest that the error signals for saccade adaptation are conveyed in a pathway that courses through the midbrain tegmentum. (jneurosci.org)
  • Signals
  • Consequently, it has been proposed that signals emerging from saccade-related brain areas provide feedback to visual cortex to change the gain of responses to visual input ( Hamker, 2005 ), increasing the signal strength as if stimulus saliency itself were increased. (jneurosci.org)
  • Because the attenuated pre-saccade activity that we found in the SC may be insufficient by itself to elicit correct anti-saccades, additional movement signals from other brain areas are presumably required. (jneurosci.org)
  • cerebellar
  • We wondered whether this natural variability would also be present in the motor commands that initiated saccades of cerebellar patients, and if so, whether these subjects would show a reduced ability to compensate for that variability. (jneurosci.org)
  • Hypometric saccades indicate a cerebellar lesion of the ocular motor vermis. (neurocular.com)
  • coordination
  • Our study fills an important gap in our understanding of eye-head coordination by combining these two approaches to compare gaze trajectories with and without whole-body rotations during saccades that are made when the head and body are fixed with respect to the chair. (jneurosci.org)
  • Both reading skills and binocular saccades coordination improve with age and children reach a similar level to adults after the age of 10. (nih.gov)
  • 1997
  • Saccade averaging has been explained in terms of a weighted average (Tipper, Howard, & Jackson, 1997 ), which assumes that each element evokes a peak of activity within a common saccade map. (arvojournals.org)
  • fovea
  • Like a flick of the wrist swivels a hand-held camera, saccades swiftly point the fovea to locations of interest, ensuring high-acuity vision for the scene's relevant information. (jneurosci.org)
  • neurons
  • These studies provide abundant evidence that an SNN is well suited to evoke the properties of the firing patterns of the premotor neurons during the pulse and slide phases of a saccade. (hindawi.com)
  • neurons are active for anti-saccades. (jneurosci.org)
  • voluntary
  • Up to 10° contralesional torsional deviations with each voluntary saccade were revealed, which also could be seen during bedside examination. (uni-muenchen.de)
  • tasks
  • Interactions between these loops and their learning capabilities are tested on different saccade tasks. (frontiersin.org)
  • As a first step, here we report a study of saccades in the gap and overlap tasks in a group of DLB patients and age-matched controls. (frontiersin.org)
  • Results
  • Here we report the results from the EEG analyses of saccade-related brain/muscle potentials using independent component analysis (ICA) and independent component (IC) clustering. (arvojournals.org)
  • magnitude
  • We found that reaction time of the secondary saccade was affected in an orderly fashion by the magnitude and direction of the preceding RPE event: the most vigorous saccades followed the largest +RPE, whereas the least vigorous saccades followed the largest −RPE. (jneurosci.org)
  • whereas
  • We probabilistically produced a combination of large or small, negative or positive RPE events and observed that saccade vigor carried a robust signature of the preceding RPE event: high vigor saccades followed +RPE events, whereas low vigor saccades followed −RPE events. (jneurosci.org)
  • cerebellum
  • Therefore, the cerebellum corrects for variability in the motor commands that initiate saccades within the same movement via an adaptive response that not only exhibits strong sensitivity to previous endpoint errors, but also rapid forgetting. (jneurosci.org)
  • predictive
  • Here, we tested whether spatio-temporal predictions are updated before, during, or shortly after an inter-hemifield saccade is executed, and thus, whether the predictive signal is transferred swiftly across hemifields. (frontiersin.org)
  • contrast
  • Here we assess concurrent changes in visual performance and perceived contrast before saccades, and show that saccade preparation enhances perception rapidly, altering early visual processing in a manner akin to increasing the physical contrast of the visual input. (jneurosci.org)
  • We found simultaneous progressive enhancement in both orientation discrimination performance and perceived contrast as time approached saccade onset. (jneurosci.org)
  • we simultaneously assessed the effects of saccade preparation on both contrast sensitivity and perceived contrast. (jneurosci.org)
  • In contrast, AD and PD patients made normal short latency saccades in the same task. (frontiersin.org)