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 distance subjects walked to reach the location where a target had been presented is plotted against the true distance of the target for three subjects. Solid and open symbols show results with and without a visible background. Error bars show s.e.m.
