Current models of spatial frequency (SF) and orientation discrimination are based on
contrast discrimination data. In these “error propagation” models, the precision of all …

The accuracy of some spatial discriminations, including spatial frequency and orientation, is
independent of the contrasts of the stimuli discriminated except when contrasts are near the …

Contrast sensitivity functions differ from observer to observer. We propose that these
differences arise because each observer has unique weights for the outputs of the neural …

Discrimination thresholds for spatial frequency and contrast were measured as a function of
(1) the spatial-frequency bandwidth of the stimuli,(2) the reference contrast of the stimuli, and …

If the spatial-frequency of sinusoidal signals in a contrast-detection experiment varies
randomly from trial to trial, then performance is decreased compared with that in a situation …

Temporal frequency discrimination was measured above threshold with a two-alternative
spatial forced-choice procedure. Stimuli were two 1 deg homogeneous fields modulated …

In standard frequency-discrimination experiments either the retinal spatial frequencies
(cycles per degree) or the object spatial frequencies (real world) could be compared …

In this study, we have compared foveal SF discriminations for luminance and color-defined
stimuli using two different tasks (criteria): in criterion-A, the discrimination is based on spatial …

Many properties of contrast detection in human vision may be described with reference to a
set of tuned spatial frequency channels. The spatial sensitivity of the channel with optimal …

Subjects were presented with two gratings with different spatial frequencies and they were
asked to discriminate one from the other. Their ability to discriminate between the gratings …