Contrast discrimination between stimuli of orthogonal orientations

Abstract

Previous investigations have shown that spatial frequency discrimination performance does not suffer when observers are made to compare the frequency of orthogonal gratings. It remains to be determined if contrast discrimination is similarly independent of the relative orientations of the two gratings to be compared. Using a 2AFC method of constant stimuli, contrast discrimination was studied under conditions in which observers compared the contrast of two orthogonal gratings. Contrast discrimination thresholds determined in this way were compared with thresholds obtained with parallel stimuli. Discrimination thresholds obtained under the two conditions were similar. © 1985 Psychonomic Society, Inc.