The perception of contrast was measured in humans by a technique of subjective contrast‐
matching, and was compared with contrast sensitivity as defined by threshold measures. 2 …

The ability of men and other ani mals to perceive the details of ob jects and scenes is
determined to a large extent by how well their visual sys tem can discern contrasts: the differ …

1. Grating contrast sensitivities have been determined over a range of spatial frequencies for
a normal subject and for subjects who are visually biased in that they have a lower …

The regional variation of contrast sensitivity along the greater extent of each of the four
principal hemi-meridia of the normal human eye was determined under photopic conditions …

The temporal characteristics of spatial contrast vision at and above threshold were assessed
psychophysically using sinusoidal gratings and a contrast-matching method. Temporal …

Contrast threshold was measured psychophysically for a sinusoidal grating presented
periodically with a variable temporal frequency for various parameters of patterns. Special …

“Contrast constancy” refers to the ability to perceive objects as maintaining a constant
contrast independent of size or distance. When tested with high contrast sinusoidal gratings …

Apparent contrast of gratings and edges was evaluated either by matching the contrast of an
adjustable pattern to a reference contrast or by subjective setting a fraction of the reference …

Long-range spatial interactions in human visual cortex were explored using a lateral
masking paradigm. Visual evoked potentials (VEPs) elicited by a Gabor signal presented in …

Contrast threshold elevation was measured in human observers at a single spatial
frequency (4 or 8 c/deg) after adaptation to gratings at different contrasts and spatial …