Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Target and background colors used in the search task. Each image shows examples of the target chromaticities against one of the 4 backgrounds that each varied along a single axis in the chromatic plane. Target chromaticities spanned a range of angles and contrasts in the plane (filled circles in the diagram) while backgrounds uniformly sampled contrast along one angle in the plane (lines in the diagram).
