Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 82 for “"saccade"”.
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Visual-auditory interstimulus contingency effects in saccade programming
… the stimuli. Human subjects were asked to make a saccade to a visual target and to use the location of an auditory accompanying stimulus as a possible, but unreliable cue for the location of the visual target. We investigated several different types of saccades. The latencies of reflexive visual …
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Saccade latency determination using video recordings from consumer-grade devices
… unobtrusively. Clinical studies have shown that saccade latency - a measure of eye movement reaction time - can be significantly different between healthy subjects and neurodegenerative disease patients. Hence, we propose and test a system that enables measurement and tracking of saccade latency …
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Influence of direction and eccentricity on pro- and anti-saccade metrics
… known as a sensorimotor transformation. The anti-saccade task can be used to investigate the ability of a subject to suppress a reflexive saccade towards a visual stimulus (pro-saccade) and generate a voluntary saccade 180° away from it. Additional steps are involved in the anti-saccade …
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Single Unit and Population Analysis of Saccade-related Fastigial Nucleus Activity in the Alert Monkey
A remarkable role in saccade control is played by the cerebellar caudal fastigial nucleus, FN (fastigial oculomotor region, FOR), which lies under the cerebellar vermis. FOR bursting activity is related to many saccade properties, such as direction, amplitude and duration. The precise mechanism by …
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Eye movement control during reading : factors and principles of computing the word center for saccade planning
… Reichle, Rayner, & Pollatsek, 2003). However, saccades’ landing positions within words during reading are in fact systematically modulated by the distance of the launch site from the word center (McConkie, Kerr, Reddix, & Zola, 1988). In general, it is largely unknown how readers identify the …
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In-between fixation and movement : on the generation of microsaccades and what they convey about saccade generation
Microsaccades are an important component of the small eye movements that constitute fixation, the basis of visual perception. The specific function of microsaccades has been a long-standing research problem. Only recently, conclusive evidence emerged, showing that microsaccades aid both visual …
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Inhibitory Control of Saccadic Eye Movements in Reading: A Neurophysiologically Based Interaction -Competition Theory of Saccade Programming
… results support and extend the I/C theory of saccade initiation and the predicted nature of inhibitory control of eye movement in reading. Further directions for exploring the underlying process of eye movement control in reading are also discussed, including the parametric adjustment of …
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Resting-state Functional Connectivity Correlates of Inhibitory Control over Emotional Stimuli
… the neural mechanisms of an emotional anti-saccade task, therefore with the use of resting-state functional magnetic resonance imaging (fMRI) and an emotional anti-saccade task, this study aims to identify the neural correlates of inhibitory control over emotional stimuli. The anti-saccade …
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"The Role of a ""Limited Retinal Search Region"" in the Perception of a Visually Stable World"
… shifts position on our retinae with each saccade, but we perceive our world as stable and continuous, a phenomenon known as visual stability. An intra-saccadic stimulus shift paradigm was used to study this phenomenon. Most theories of visual stability implicitly assume the existence of a …
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Visual working memory supports perceptual stability across saccadic eye movements
… in the retinal information resulting from a saccade. In contrast, more contemporary theories have proposed that perceptual stability relies on object correspondence across saccades, perhaps limited to the saccade target alone. According to these views, the visual system encodes features of …
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Role of the Parabigeminal Nucleus in Visuomotor Behavior
… moving targets primarily with small catch-up saccades, and for target speeds of 2--6 deg/s, they did so with sufficient accuracy to keep targets within 2.5 deg of the visual axis most of the time. During intersaccade intervals of such close-order tracking, PBN cells fired at rates related to …
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Characterizing the Brain Dynamics and Eye Movement Behavior of Memory-Guided Saccades: a Preliminary Investigation of Distractor Influence on Memory-Guided Saccades
… mechanisms of distractors on memory-guided saccades. In our current study we have utilized eye tracking and EEG technology to simultaneously record the changes in saccadic eye movement (SEM) behavior and event-related potentials (ERPs) associated with performance on a memory-guided saccade …
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Eye-Tracking Measures of Attentional Bias In Cocaine Dependent Subjects
… DLPFC) in voluntary eye control (i.e., anti-saccades) and more reflexive saccades driven by involuntary midbrain (superior colliculus) perceptual input (i.e., pro-saccades). In addition, neuroimaging studies in patients with cocaine dependence have shown activation in frontal regions during …
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Using Eye Movements to Establish a Normative Database of Control Participants Across the Lifespan
… eye tracker capable of measuring various saccade metrics on an interleaved pro- and anti-saccade task in healthy participants 5-85 years of age. The interleaved pro- and anti-saccade task requires the generation of pro-saccades (automatic eye movements toward a salient stimulus) and/or …
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Optogenetic disruption of memory-drive, oculomotor behavior in the non-human primate
… eye field (FEF) is critical for executing saccades to remembered locations. FEF neurons increase their firing rate during the three epochs of the memory-guided saccade task: visual stimulus presentation, the delay interval, and motor preparation. It is unclear, though, whether FEF activity …
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Cognitive impairment in chronic kidney disease : are oculomotor tests an effective detection marker?
… specifically uncorrected error rate in the anti-saccade paradigm. This particular measure examines individuals’ inhibitory control, self-monitoring and executive functioning abilities. Consequently, these facets of cognitive functioning are commonly found to be impaired in people with CKD. This …
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Deficits in eye movement control in children with 22q11.2 deletion syndrome.
… 32 age- and sex-matched controls completed prosaccade, antisaccade, delayed memory-guided sequential (DMS) and predictive eye movement tasks. Results: Compared to controls, children with 22q11.2 DS exhibited increased direction errors in the antisaccade task, increased timing errors in the DMS …
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Visual orienting to eye gaze in individuals with high and low levels of autistic traits
… traits were compared on their performance of pro-saccade and anti-saccade cueing tasks with gaze and arrow distracters. Eye movements to these tasks were recorded. Results indicated no differences in orienting between the high and low group. This suggests that the atypical cueing effects found in …
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Impact of Central Vision Loss on Eye Movements and Time-to-Contact Judgments
… in both unimodal and multimodal conditions. Saccade amplitude, saccade duration, and fixation duration were recorded in all trials. ii Results: Results showed that saccadic eye movements predict TTC estimates in the unimodal condition but not in the multimodal condition. Further, for both …
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