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Current Opinion in Neurobiology Dec 1994Recent experiments on the cat and monkey have revealed several different cell types within the superior colliculus, including fixation, burst, and build up cells. During... (Review)
Review
Recent experiments on the cat and monkey have revealed several different cell types within the superior colliculus, including fixation, burst, and build up cells. During primate saccades, activity remains fixed at one location in burst cells, but spreads across the colliculus in build up cells. New models based on the activity of these cell types suggest their functional roles in saccade generation.
Topics: Animals; Cats; Feedback; Fixation, Ocular; Haplorhini; Models, Neurological; Motor Activity; Neurons; Saccades; Superior Colliculi
PubMed: 7888769
DOI: 10.1016/0959-4388(94)90134-1 -
Nihon Jibiinkoka Gakkai Kaiho Feb 1969
Topics: Fixation, Ocular; Humans; Nystagmus, Pathologic
PubMed: 5388790
DOI: No ID Found -
Journal of Vision Oct 2013Whenever eye movements are measured, a central part of the analysis has to do with where subjects fixate and why they fixated where they fixated. To a first...
Whenever eye movements are measured, a central part of the analysis has to do with where subjects fixate and why they fixated where they fixated. To a first approximation, a set of fixations can be viewed as a set of points in space; this implies that fixations are spatial data and that the analysis of fixation locations can be beneficially thought of as a spatial statistics problem. We argue that thinking of fixation locations as arising from point processes is a very fruitful framework for eye-movement data, helping turn qualitative questions into quantitative ones. We provide a tutorial introduction to some of the main ideas of the field of spatial statistics, focusing especially on spatial Poisson processes. We show how point processes help relate image properties to fixation locations. In particular we show how point processes naturally express the idea that image features' predictability for fixations may vary from one image to another. We review other methods of analysis used in the literature, show how they relate to point process theory, and argue that thinking in terms of point processes substantially extends the range of analyses that can be performed and clarify their interpretation.
Topics: Computer Simulation; Eye Movements; Fixation, Ocular; Humans; Space Perception
PubMed: 24084942
DOI: 10.1167/13.12.1 -
Strabismus Jun 2000Heterophoria does not provide a reliable clue for ordering prisms in an asthenopic patient. The same reservation applies to associated phoria, as determined by prism... (Review)
Review
Heterophoria does not provide a reliable clue for ordering prisms in an asthenopic patient. The same reservation applies to associated phoria, as determined by prism correction of fixation disparity. Subjective tests for fixation disparity, even those with a fusionable fixation target, do not correctly indicate the vergence position of the eyes under natural viewing conditions. Attempts to measure fixation disparity on the basis of stereo disparity, using the "Measuring and Correction Methods of H.-J. Haase", have failed.
Topics: Eyeglasses; Fixation, Ocular; Humans; Strabismus; Vision Disparity
PubMed: 10980694
DOI: No ID Found -
Proceedings. Biological Sciences Feb 2019According to the natural pedagogy theory, infant gaze following is based on an understanding of the communicative intent of specific ostensive cues. However, it has...
According to the natural pedagogy theory, infant gaze following is based on an understanding of the communicative intent of specific ostensive cues. However, it has remained unclear how eye contact affects this understanding and why it induces gaze following behaviour. In this study, we examined infant arousal in different gaze following contexts and whether arousal levels during eye contact predict gaze following. Twenty-five infants, ages 9-10 months participated in this study. They watched a video of an actress gazing towards one of two objects and then either looking directly into the camera to make eye contact or not showing any communicative intent. We found that eye contact led to an elevation in the infants' heart rates (HRs) and that HR during eye contact was predictive of later gaze following. Furthermore, increases in HR predicted gaze following whether it was accompanied by communicative cues or not. These findings suggest that infant gaze following behaviour is associated with both communicative cues and physiological arousal.
Topics: Arousal; Attention; Cues; Female; Fixation, Ocular; Humans; Infant; Male
PubMed: 30963922
DOI: 10.1098/rspb.2018.2746 -
Vision Research Sep 2019Good vision requires a near stationary image if motion blur is to be avoided. All animals with good eyesight (principally the vertebrates, arthropods and cephalopod... (Comparative Study)
Comparative Study
Good vision requires a near stationary image if motion blur is to be avoided. All animals with good eyesight (principally the vertebrates, arthropods and cephalopod molluscs) have adopted a very similar strategy for achieving this: fixations in which gaze is kept still, with saccades to change gaze direction as fast as possible. In all these groups the stability of fixations is maintained by reflexes that oppose the effects of head or body movement (the vestibulo-ocular reflex in vertebrates), and that oppose drift of the image on the retina (optokinetic and optomotor reflexes). A small number of species of molluscs and arthropods have adopted a different strategy: allowing the retinas to scan across the surroundings to acquire information. The retinas in these animals are all linear structures a few receptors wide, and scan at right angles to their long dimension. The speed of scanning varies with retinal resolution, ensuring that scan speed does not produce deleterious blur.
Topics: Animals; Eye Movements; Fixation, Ocular; Humans; Nystagmus, Optokinetic; Reflex, Vestibulo-Ocular
PubMed: 31254533
DOI: 10.1016/j.visres.2019.06.004 -
Graefe's Archive For Clinical and... May 2006The eye is moved so that the object of interest falls on the central fovea, where the spatial resolution is highest. In the present study we quantified eye movements of...
BACKGROUND
The eye is moved so that the object of interest falls on the central fovea, where the spatial resolution is highest. In the present study we quantified eye movements of normal test persons during steady fixation and characterized the fixation using a 3D fixation plot (X horizontal eye position, Y vertical eye position, Z time in each eye position).
METHOD
Fixation eye movements were quantified binocularly in ten normal test persons during a 40-s fixation task using an infrared recording technique.
RESULTS
The fixation plot was characterized by a single preferred fixation locus in 17 eyes. One eye had two distinctly separated preferred fixation locations and in two eyes the configuration of fixation plot was flat with no single identifiable locus of fixation. The fixation plots were elliptical along the horizontal meridian in 9 eyes, elliptical along the vertical meridian in 8 eyes, and round in 3 eyes. The fixation area (RAF95) ranged between 1418 and 14182 arcmin(2), and a significant positive correlation was found between RAF95 and the mean microsaccadic amplitude (p<0.001).
CONCLUSION
The fixation plots are often characterized by a single preferred fixation locus but may also be almost flat with no identifiable location of fixation. The individual fixations patterns resembles the cone density contour plots as found in histological studies, and it may be speculated, that the shape of the fixation plot is determined by the cone density topography.
Topics: Adult; Eye Movements; Fixation, Ocular; Humans; Middle Aged; Vision Tests; Vision, Binocular
PubMed: 16170533
DOI: 10.1007/s00417-004-0869-z -
Neural Computation Jul 2001The neural origin of the steady-state vergence eye movement error, called binocular fixation disparity, is not well understood. Further, there has been no study that...
The neural origin of the steady-state vergence eye movement error, called binocular fixation disparity, is not well understood. Further, there has been no study that quantitatively relates the dynamics of the vergence system to its steady-state behavior, a critical test for the understanding of any oculomotor system. We investigate whether fixation disparity can be related to the dynamics of opponent convergence and divergence neural pathways. Using binocular eye movement recordings, we first show that opponent vergence pathways exhibit asymmetric angle-dependent gains. We then present a neural model that combines physiological properties of disparity-tuned cells and vergence premotor cells with the asymmetric gain properties of the opponent pathways. Quantitative comparison of the model predictions with our experimental data suggests that fixation disparity can arise when asymmetric opponent vergence pathways are driven by a distributed disparity code.
Topics: Accommodation, Ocular; Eye Movements; Fixation, Ocular; Humans; Models, Neurological; Nerve Net; Vision, Binocular
PubMed: 11440595
DOI: 10.1162/089976601750264983 -
Journal of Neural Engineering Aug 2012
Topics: Brain-Computer Interfaces; Fixation, Ocular; Humans
PubMed: 22831863
DOI: 10.1088/1741-2560/9/4/040201 -
Journal of Vision Oct 2020As humans move through parts of their environment, they meet others that may or may not try to interact with them. Where do people look when they meet others? We had...
As humans move through parts of their environment, they meet others that may or may not try to interact with them. Where do people look when they meet others? We had participants wearing an eye tracker walk through a university building. On the way, they encountered nine "walkers." Walkers were instructed to e.g. ignore the participant, greet him or her, or attempt to hand out a flyer. The participant's gaze was mostly directed to the currently relevant body parts of the walker. Thus, the participants gaze depended on the walker's action. Individual differences in participant's looking behavior were consistent across walkers. Participants who did not respond to the walker seemed to look less at that walker, although this difference was not statistically significant. We suggest that models of gaze allocation should take social motivation into account.
Topics: Adult; Eye Movements; Female; Fixation, Ocular; Humans; Male; Walking
PubMed: 33007079
DOI: 10.1167/jov.20.10.5