Abstract

The present experiment explores the influence of color on set-size effects in a visual search task. In the initial measurements, discrimination thresholds for luminance-defined and chromatically defined (red) targets were measured for set sizes of 2 and 8. Displays were constructed with white surrounds to control adaptation, restricted eccentricities and spacing to control these effects, randomized stimulus positions to avoid configural cues, and lowpass stimuli in both time and space to maximize chromatic sensitivity. Preliminary results show approximately equal set-size effects for both luminance and chromatic targets. Results will be compared with those of earlier studies of how different tasks affect the shapes of discrimination ellipsoids in 3-dimensional color space.

© 1992 Optical Society of America