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.
The target patterning that was used (a) background matching, created using a 1/f function; (b) black; (c) grey (mean luminance). Below each target is an example of how the target would appear on a background. A red outline has been added to highlight the position of the target on the background (not present during the experiment).
