Fixation (visual)

About: Fixation (visual) is a research topic. Over the lifetime, 6131 publications have been published within this topic receiving 293481 citations. The topic is also known as: ocular fixation & Fixation, Ocular.

The neurology of eye movements

Abstract: The Neurology of Eye Movements, Edition 5, by R. John Leigh, M.D. and David S. Zee MD Foreword Chapter 1: A Survey of Eye Movements: Characteristics and Teleology Chapter 2: The Ocular Motor Periphery Chapter 3: The Vestibular-Optokinetic System Chapter 4: The Saccadic System Chapter 5: Smooth Visual Tracking and Fixation Chapter 6: Gaze Holding and The Neural Integrator Chapter 7: The Neural Basis for Conjugate Eye Movements Chapter 8: Eye-Head Movements Chapter 9: Vergence Eye Movements Chapter 10: Diagnosis of Peripheral Ocular Motor Palsies And Strabismus Chapter 11: Diagnosis of Nystagmus and Saccadic Intrusions Chapter 12: Diagnosis and Management of Vestibular Disorders Chapter 13: Disorders of Ocular Motility Due To Disease of the Brainstem, Cerebellum and Diencephalon Chapter 14: Disorders of Ocular Motility With Disease Affecting The Basal Ganglia, Cerebral Cortex, And In Systemic Conditions Appendix A: A Summary Scheme for the Bedside Ocular Motor Examination Appendix B: A Summary of Methods for Measuring Eye Movements Appendix C: Tables of Ocular Motor Findings in Hereditary Ataxias Appendix D: Table of Videos and their Legends

Mnemonic coding of visual space in the monkey's dorsolateral prefrontal cortex

Abstract: 1. An oculomotor delayed-response task was used to examine the spatial memory functions of neurons in primate prefrontal cortex. Monkeys were trained to fixate a central spot during a brief presentation (0.5 s) of a peripheral cue and throughout a subsequent delay period (1-6 s), and then, upon the extinction of the fixation target, to make a saccadic eye movement to where the cue had been presented. Cues were usually presented in one of eight different locations separated by 45 degrees. This task thus requires monkeys to direct their gaze to the location of a remembered visual cue, controls the retinal coordinates of the visual cues, controls the monkey's oculomotor behavior during the delay period, and also allows precise measurement of the timing and direction of the relevant behavioral responses. 2. Recordings were obtained from 288 neurons in the prefrontal cortex within and surrounding the principal sulcus (PS) while monkeys performed this task. An additional 31 neurons in the frontal eye fields (FEF) region within and near the anterior bank of the arcuate sulcus were also studied. 3. Of the 288 PS neurons, 170 exhibited task-related activity during at least one phase of this task and, of these, 87 showed significant excitation or inhibition of activity during the delay period relative to activity during the intertrial interval. 4. Delay period activity was classified as directional for 79% of these 87 neurons in that significant responses only occurred following cues located over a certain range of visual field directions and were weak or absent for other cue directions. The remaining 21% were omnidirectional, i.e., showed comparable delay period activity for all visual field locations tested. Directional preferences, or lack thereof, were maintained across different delay intervals (1-6 s). 5. For 50 of the 87 PS neurons, activity during the delay period was significantly elevated above the neuron's spontaneous rate for at least one cue location; for the remaining 37 neurons only inhibitory delay period activity was seen. Nearly all (92%) neurons with excitatory delay period activity were directional and few (8%) were omnidirectional. Most (62%) neurons with purely inhibitory delay period activity were directional, but a substantial minority (38%) was omnidirectional. 6. Fifteen of the neurons with excitatory directional delay period activity also had significant inhibitory delay period activity for other cue directions. These inhibitory responses were usually strongest for, or centered about, cue directions roughly opposite those optimal for excitatory responses.(ABSTRACT TRUNCATED AT 400 WORDS)

Eye movements and attention in reading, scene perception, and visual search.

Abstract: Eye movements are now widely used to investigate cognitive processes during reading, scene perception, and visual search. In this article, research on the following topics is reviewed with respect to reading: (a) the perceptual span (or span of effective vision), (b) preview benefit, (c) eye movement control, and (d) models of eye movements. Related issues with respect to eye movements during scene perception and visual search are also reviewed. It is argued that research on eye movements during reading has been somewhat advanced over research on eye movements in scene perception and visual search and that some of the paradigms developed to study reading should be more widely adopted in the study of scene perception and visual search. Research dealing with "real-world" tasks and research utilizing the visual-world paradigm are also briefly discussed.