Showing papers in "Vision Research in 1983"

TL;DR: The variability of the discharge of visual cortical neurons in cats and macaque monkeys limits the reliability with which such neurons can relay signals about weak visual stimuli.

TL;DR: Reduced retinal illuminance characteristic of the aged eye could account for a large part of older adults' deficit in spatial vision, but appeared to play little role in their deficit in temporal vision.

TL;DR: Threshold elevations were measured as a function of the spatial frequency of high contrast cosine masks using spatially localized test stimuli with a 1.0 octave bandwidth, suggesting the existence of discrete spatial frequency mechanisms in human central vision.

TL;DR: This theory is interpreted in terms of a general and primitive code for the transduction of local and widespread spatial luminance changes, in which stationary points in an approximation to the second derivative are detected and localized.

TL;DR: After intracellular recording, bipolar cells of the cat retina have been stained with HRP and their contacts in the outer and inner plexiform layers examined by electron microscopy.

TL;DR: An analysis of the threshold vs intensity function shows how each of these mechanisms contributes to produce Weber behaviour.

TL;DR: The disparity range for stereo sensitivity was investigated with spatially filtered bars, tuned narrowly over a broad range of spatial frequencies, and it was revealed that greater amounts of uncrossed than crossed disparity were required to match suprathreshold disparities.

TL;DR: The improvement in stereoacuity of two inexperienced, normal subjects was compared at foveal and at 2.5 degrees and 5 degrees peripheral target locations as a function of practice and practice-stabilized disparity thresholds revealed a steeper deterioration than did measurements of the same subjects' minimum angles of resolution (MAR).

TL;DR: The results suggest that magnocellular cells are well suited for the detection of any spatially localized change, be it the result of luminance or wavelength change.

TL;DR: The neural architecture of on and off pathways in mammalian retina is described, including the development of ideas leading to an understanding of the bisublaminar organization of the inner plexiform layer of the retina which supports these two pathways.

TL;DR: All parameters showed considerable intersubject variability for both age groups and decreased velocities or increased durations outside of these normal, broad ranges should be regarded as pathological for all subjects; they are not physiological effects of the aging process.

TL;DR: Neurons involved in the transfer of rod signals to the ganglion cells in the retina of the cat have been recorded from and stained with horseradish peroxidase and their synaptic connections determined by electron microscopy.

TL;DR: This study shows that humans can learn to perform zero-latency tracking of targets that move with continuous velocity and amplitude-limited acceleration.

TL;DR: An experiment is presented that argues against the idea that a kind of photographic representation of their visual environment is constructed from "snapshots" taken by successive eye fixations, and an alternative explanation is put forward to explain why the authors see the environment as being stable and continuous despite eye movements.

TL;DR: Contrast detection thresholds for spatiotemporal colour modulation were determined at several retinal locations and did not find any retinal location along the horizontal meridian which was red-green or yellow-blue colour blind.

TL;DR: It is concluded that the major achromatic channel for human foveal vision originates within the r-g color-opponent channel, and the interaction between the spatial and spectral variables for the simple-opponents cells which predominate in primate fovea vision is made explicit.

TL;DR: Two-dimensional band-pass filtered random-dot cinematograms were used to study apparent movement mediated by the short-range process and maximum displacement (dmax) was found to be commensurate with the length of the clusters in the direction of the movement.

TL;DR: Binocular summation experiments showed that even though the relative difference between the monocular sensitivities was small or absent for the monkeys reared with optical dissociation or chronic monocular cycloplegia, none of them demonstrated binocular vision in these experiments.

TL;DR: Spatial localization of an amblyopic eye depends upon both the type of amblyopia, and the stimulus configuration, and strabismic amblyopes show disturbances in both spatial localization tasks which can not be accounted for on the basis of reduced resolution.

TL;DR: It is found that any object which moves in one du-ection at uniform velocity will tend to be perceived as continuing its motion in that direction (Ramachandran and Anstis 1981), which might be regarded as a perceptual equivalent of Newton’s first law.

TL;DR: In this paper, the observer adds intrinsic variance to whatever variance is present in the numbers displayed, the errors depending upon the sum of the two, and they found no evidence for incomplete use of information presented, other than this observer variance.

TL;DR: Split beams of varying separations from a helium-neon laser were directed through the crystalline lenses of a number of vertebrates to indicate the extent to which the refractive index variation of the lens and lens shape control spherical aberration.

TL;DR: Vernier acuity demonstrates a fine sense of relative visual location, which can be exploited to examine the question of mechanisms for the extraction of position information, and is best described by a model which encodes only the occurrence and location of zero-crossings in the second derivative of the retinal light distribution.

TL;DR: The finest human stereoacuity, which in some gifted individuals amounts to the detection of binocular disparities of less than 5 arc sec, is found with isolated vertical target lines 10-15 min of arc in length.

TL;DR: It is concluded that APB may be useful as a pharmacological tool to differentiate On and Off pathways in the rabbit visual system.

TL;DR: A topographic map of nerve fiber layer thickness was prepared from serial sections of the retina of the cynomolgus monkey to determine the relative proportions of axons and of glial processes within a given nerve fiber bundle at various positions across the retina.

TL;DR: Comparison of the membrane potential and calculated chloride equilibrium potential shows that retinal neurons differ in relative transmembrane chloride distribution, consistent with the idea that chloride ions may play a role as a depolarizing driving force for electrogenic activity of horizontal cells and on-bipolars.

TL;DR: Contrast sensitivity, measured as a function of retinal eccentricity for stimuli differing in temporal and spatial frequency, was maximum at the fovea and declined linearly with eccentricity, indicating that the visual field is homogeneous in sensitivity for change in contrast over time.

TL;DR: The similarity in shape of contrast discrimination functions for light and dark bars is attributed to a retinal nonlinear intensity transformation and can be explained by differences in temporal integration.

TL;DR: These changes in membrane potential are the origin, respectively, of the RPE component of the ERG c-wave, the fast oscillation, and the light peak (slow oscillation) in retinal pigment epithelial cell (RPE) membrane potentials.