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.
Bistable biological motion. The schematic illustrates how a standard PL walker can be perceived with either of two heading directions; in the experiments reported in this paper, observers viewed a bistable PL walker that could be perceived as facing 30° left (frontward-facing) or 150° left (backward-facing) of the observer's line of sight.
