Journal ArticleDOI
The functional area for summation to threshold for sinusoidal gratings.
E.R. Howell,Robert F. Hess +1 more
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TLDR
This result suggests that there is a functional summation of responses of detecting elements at threshold over an area the size of which is reciprocally related to the spatial frequency.About:
This article is published in Vision Research.The article was published on 1978-01-01. It has received 266 citations till now. The article focuses on the topics: Spatial frequency & Grating.read more
Citations
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Journal ArticleDOI
The contrast sensitivity of human colour vision to red‐green and blue‐yellow chromatic gratings.
TL;DR: Results show that, at low spatial frequencies below 0.5 cycles/deg, contrast sensitivity is greater to the chromatic gratings, consisting of two monochrome gratings added in antiphase, than to either monochromatic grating alone.
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Probability summation and regional variation in contrast sensitivity across the visual field.
John G. Robson,Norma Graham +1 more
TL;DR: Compared sensitivity at different positions in the visual field has been measured at various spatial frequencies using a patch of grating suitably vignetted to give a stimulus localized in both space and spatial frequency to explain the relation between sensitivity and number of cycles.
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Visual resolution, contrast sensitivity, and the cortical magnification factor
Veijo Virsu,J. Rovamo +1 more
TL;DR: The results indicated specificly that visual patterns can be made equally visible if they are scaled so that their calculated cortical representations become equivalent and the power law of spatial summation suggests the existence of a central integrator that pools the activity of cortical neurons.
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A theoretical and experimental case for a visual deficit in specific reading disability
TL;DR: In this article, the authors present three lines of evidence indicating a low-level visual deficit in a large percentage of specifically-disabled readers, which they present within the theoretical framework of spatial frequency analysis, in particular the framework of transient and sustained subsystems.
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Sequential ideal-observer analysis of visual discriminations.
TL;DR: A new analysis is described, based on the concept of the ideal observer in signal detection theory, that allows one to trace the flow of discrimination information through the initial physiological stages of visual processing, for arbitrary spatio-chromatic stimuli.
References
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Journal ArticleDOI
Application of fourier analysis to the visibility of gratings
F. W. Campbell,John G. Robson +1 more
TL;DR: The contrast thresholds of a variety of grating patterns have been measured over a wide range of spatial frequencies and the results show clear patterns of uniformity in the response to grating noise.
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Optical and retinal factors affecting visual resolution.
F. W. Campbell,D G Green +1 more
TL;DR: An improved version of the well-known interference fringe technique which theoretically allows a sinusoidal pattern of very high contrast to be formed directly on the retina to be obtained without prior modification by the optics of the eye is reported.
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The influence of the number of cycles upon the visual contrast threshold for sptial sine wave patterns
TL;DR: Spatial contrast measurements have been carried out with sine wave modulated fields, varying the aperture and the luminance and the modulation threshold turns out to depend upon the number of cycles in the stimulus for numbers of cycles below a critical number ofcycles.
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Edge detectors in human vision
Robert Shapley,David J. Tolhurst +1 more
TL;DR: The spatial properties of edge detectors were measured psychophysically with the technique of subthreshold addition using lines, sine gratings, Gaussian edges, and ramps.
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Visibility of aperiodic patterns compared with that of sinusoidal gratings
TL;DR: Using experimental curves relating the threshold contrast of sinusoidal grating patterns to their spatial frequency, the expected threshold contrast curves for three aperiodic patterns are calculated and it is made that the system is linear near the threshold.