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  • fixation
  • 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)
  • The preparation time course of an action (e.g., a saccade) has been widely studied with the gap/overlap paradigm with temporal asynchronies (TA) between peripheral target onset and fixation point offset (gap, synchronous, or overlap). (jneurosci.org)
  • Human subjects made saccades to targets with different TAs with respect to fixation point offset and reported whether they perceived the stimuli as separated by a gap or overlapped in time. (jneurosci.org)
  • Furthermore, dyslexics made more saccades during the last 15 s of fixation period with respect to both groups of non-dyslexic children. (frontiersin.org)
  • These authors recorded fixation activity and saccade suppression in two monkeys 48 h after muscimol injection in the rostral cells of the superior colliculus (SC), and showed that muscimol inhibits the neural transmission of the rostral cells. (frontiersin.org)
  • This study showed that rostral cells of the SC are involved in both visual fixation and saccade suppression. (frontiersin.org)
  • In 1995, the same authors explored further the role of SC cells in monkeys and they confirmed that some cells in the rostral pole are responsible for visual fixation while the other cells are responsible for preparation and generation of saccades ( Munoz and Wurtz, 1995 ). (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)
  • anti-saccades
  • 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)
  • 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)
  • To date, the contribution of the SC to the generation of anti-saccades is unknown. (jneurosci.org)
  • optokinetic
  • To substantiate this dichotomy, here in this article I reviewed recent data on neuronal connections and signal contents of climbing fibers in the vestibuloocular reflex (VOR), optokinetic eye movement response, saccade, hand reaching, cursor tracking, as well as some other cases of motor control. (frontiersin.org)
  • disconjugacy
  • This transient saccade disconjugacy is traditionally believed to reflect peripheral asymmetries (pre-motor circuits and visco-elastic properties of the ocular muscles, see, e.g. (frontiersin.org)
  • and (iii) ocular motor behavior in the visual search tasks is similar for dyslexic children and for typical readers, except for the disconjugacy during and after the saccade: dyslexic children are impaired in comparison to typical children. (frontiersin.org)
  • evokes
  • When the image of a target is outside the fovea at the end of a saccade, it evokes a climbing fiber response retinotopically on the contralateral cerebellar vermis. (arvojournals.org)
  • stimuli
  • They took advantage of the long integration time for motion stimuli [ 8 ] and showed that observers can integrate motion signals that are individually below threshold (and hence not perceived when presented alone) across saccades. (royalsocietypublishing.org)
  • signals
  • Importantly, the methodology excluded cognitive strategies or verbal coding as the motion signals presented before and after the saccade were each well below the conscious detection threshold: only by summating the two signals could motion be correctly discriminated. (royalsocietypublishing.org)
  • Integration of motion signals across saccades. (royalsocietypublishing.org)
  • cerebellar
  • We propose a saccade control model, with emphasis on the structure of the OMV and its interaction with the extra-cerebellar components. (frontiersin.org)
  • 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)
  • Here we present a cerebellar model with the same LTD and LTP mechanism to explain the saccade adaptation in the amplitude as well as direction by repetitive intrasaccadic target displacement (McLaughlin, 1967, Miller et al. (arvojournals.org)
  • adaptive
  • The OMV, through the caudal fastigial nuclei, interacts with the brainstem to provide adaptive saccade gain corrections that minimize the visual error in reaching a given target location. (frontiersin.org)
  • 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)
  • variability
  • Healthy people showed within-saccade compensation for this variability with commands that arrived later in the same saccade. (jneurosci.org)
  • This ability to correct for variability in the motor commands that initiated a saccade was a predictor of each subject's ability to learn from endpoint errors. (jneurosci.org)
  • Despite this variability in the motor commands that initiate saccades, the brain accurately guides the eyes to the target. (jneurosci.org)
  • If the internal feedback is intact, variability in the commands that initiate the saccade might be compensated via commands that arrive later during the same saccade. (jneurosci.org)
  • pretarget
  • This view is supported by cases in which exceptionally high levels of pretarget activity were associated with anticipatory saccades into the response field of a neuron that occurred in advance of the target being presented. (jneurosci.org)
  • lesions
  • In addition, monkeys with unilateral lesions exhibited specific impairment only in the performance of memory-guided saccades directed toward visual cues in the visual field contralateral to the lesioned hemisphere. (frontiersin.org)
  • Monkeys
  • To distinguish between these two hypotheses, we recorded single neuron activity in the SC of awake behaving rhesus monkeys trained to perform saccades in a task with randomly interleaved pro-saccade and anti-saccade trials. (jneurosci.org)
  • frontal
  • The frontal eye field (FEF), supplementary eye field (SEF), and dorsolateral prefrontal cortex (DPC) are considered to be the predominate brain regions involved in the generation of incongruent saccades. (jneurosci.org)
  • rTMS over the right frontal eye field (FEF) slowed the time to make the first saccade. (frontiersin.org)
  • The frontal eye field (FEF) is known to play also an important role in the control of saccades and in their suppression ( Leigh and Zee, 2006 ). (frontiersin.org)
  • Theeuwes
  • Distractor- and target-related activity thus merge into one resultant vector which directs the saccade to a weighted average location between the elements (see also Godijn & Theeuwes, 2002 ). (arvojournals.org)
  • preparation
  • Given that this time includes saccade preparation, this seems to imply that the underlying visual processing can be done in 100 ms or less. (arvojournals.org)
  • 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)
  • 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)
  • we simultaneously assessed the effects of saccade preparation on both contrast sensitivity and perceived contrast. (jneurosci.org)
  • Riehle and Requin, 1993 ) have detailed three operational criteria for labeling changes in neuronal discharge as motor preparation. (jneurosci.org)
  • tasks
  • 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)
  • Interactions between these loops and their learning capabilities are tested on different saccade tasks. (frontiersin.org)
  • dyslexic children
  • Results showed that dyslexic children produced a significantly higher number of unwanted saccades than both groups of non-dyslexic children. (frontiersin.org)
  • Moreover, the number of unwanted saccades significantly decreased with age in both groups of non-dyslexic children, but not in dyslexics. (frontiersin.org)