Contrast sensitivity to angular frequency gratings is not higher than to Cartesian gratings

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Contrast sensitivity to angular frequency gratings is not higher than to Cartesian gratings.

When contrast sensitivity functions to Cartesian and angular gratings were compared in previous studies the peak sensitivity to angular stimuli was reported to be 0.21 log units higher. In experiments carried out to repeat this result, we used the same two-alternative forced-choice paradigm, but improved experimental control and precision by increasing contrast resolution from 8 to 12 bits, inc...

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Contrast sensitivity to angular frequency stimuli is higher than that for sinewave gratings in the respective middle range.

This study compares contrast thresholds for sinewave gratings, or spatial frequencies (1/CSF) with contrast thresholds for angular frequencies (1/aCSF) and for radial frequencies, or Jzero targets (1/rCSF). Observers had to differentiate between one of these frequency stimuli and a stimulus at mean luminance within a forced-choice procedure. All measurements were made with the same equipment, m...

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Early malnutrition decreases contrast sensitivity to circular concentric gratings

Early malnutrition refers to inadequate nutrition during the critical period of nervous system development followed by nutritional recovery, resulting in a short stature according to age but normal weight according to short stature. We measured the effects of early malnutrition on contrast sensitivity (CS) to concentric circular gratings in 18 children of both sexes, aged 8 to 11 years (mean = ...

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Contrast sensitivity gratings in glaucoma family screening.

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Peripheral contrast sensitivity for sine-wave gratings and single periods.

The contrast sensitivity of the human eye has been measured as a function of eccentricity. The stimulus used was a sine-wave grating with a fixed height of 5’. in a surround of luminance that equals the average stimulus luminance. The measurements were carried out with stimulus width as the independent variable. The “local’. sensitivity for gratings was found to decrease monotonically with incr...

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ژورنال

عنوان ژورنال: Brazilian Journal of Medical and Biological Research

سال: 2004

ISSN: 0100-879X

DOI: 10.1590/s0100-879x2004000200010