Results 221 to 230 of about 530,690 (264)

Perceptual latency and spatial frequency

Vision Research, 1987
Subjects estimated the perceived onset of sinusoidal gratings by adjusting a visual probe so that grating and probe were phenomenally simultaneous. The first experiment found that perceptual latency increased by an average of 21 msec over a range of 0.5-9.0 c/deg, or approximately 5 msec per octave of spatial frequency.
D M, Parker, S, Dutch
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Spatial-Frequency Adaptation and Afterimages

Perception, 1977
The contribution of afterimages to spatial-frequency adaptation was studied by comparing a number of different fixation paradigms designed to maximize or minimize afterimages. While it is clear that adaptation is not an afterimage artifact, nevertheless afterimages are produced at low spatial frequencies and can considerably distort the results of ...
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Observations on Spatial-Frequency Doubling

Perception, 1974
The involvement of disparity detectors in the perception of spatial-frequency doubling in a flickering grating was tested by viewing the grating horizontally. Frequency doubling was unimpaired, and must therefore occur independently of disparity detection.
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Joint spatial/spatial-frequency representation

Signal Processing, 1988
Abstract In this paper, we first consider the motivations for current interest in the application of conjoint signal representations to problems in visual processing and form representation. The issue of conjoint resolution is then discussed, especially as it pertains to joint energy and pseudo-energy signal representations.
Lowell D Jacobson, Harry Wechsler
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Orientation discrimination depends on spatial frequency

Vision Research, 1991
Thresholds were measured for discriminating the orientation of sinusoidal gratings of varying spatial frequency, and found to decrease monotonically with increasing spatial frequency. For discrimination of high-contrast (10 times threshold) near-vertical gratings, thresholds ranged from about 1 deg at 0.04 c/deg to 0.5 deg at 0.2 c/deg, after which ...
BURR, DAVID CHARLES, S. A. WIJESUNDRA
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Masking of spatial-frequency discrimination

Journal of the Optical Society of America A, 1985
Spatial-frequency discrimination thresholds were measured using the temporal two-alternative forced-choice procedure. A superimposed masker grating reduced discrimination threshold more than 20-fold when the spatial frequency of the masker was close to the test spatial frequency because moiré fringes provided a sensitive cue to the test grating's ...
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Locus of spatial-frequency discrimination

Journal of the Optical Society of America A, 1987
In standard frequency-discrimination experiments either the retinal spatial frequencies (cycles per degree) or the object spatial frequencies (real world) could be compared, because the retinal and object frequency differences are the same. Current models of spatial-frequency discrimination assume that observers compare the retinal frequencies.
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Spatial frequency selectivity in the retina

Vision Research, 1975
Abstract Retinal sensitivity to spatial patterns depends on the spatial distribution of receptive fields. Their natural distribution is neither perfectly random nor perfectly regular; its effects vary with the visual task involved. A model of the sustained ganglion cell in man is used to make quantitative predictions of the sine-wave contrast ...
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Spatial-frequency adaptation affects spatial-probability summation

Journal of the Optical Society of America, 1983
The effects of spatial-frequency adaptation on spatial-probability summation were investigated by two techniques: the measurement of the dependence of cosine grating sensitivity on the number of cycles presented and the determination of the frequency-of-seeing curve for a cosine grating.
D W, Williams, H R, Wilson
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Model-based analysis on the influence of spatial frequency selection in spatial frequency domain imaging

Applied Optics, 2015
Frequency variation in spatial frequency domain imaging is a powerful tool for adjusting the penetration depth of the imaging signal and the parameter sensitivity toward absorption and diffusive and subdiffusive scattering. Through our computational analysis, using an analytical solution of the radiative transfer equation, we add quantitation to this ...
Nico, Bodenschatz, Philipp, Krauter, André, Liemert, Joachim, Wiest, Alwin, Kienle   +4 more
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