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.
Psychometric curve fit (black line) for a single condition and subject. Circles indicate the fraction of trials at each stimulus velocity in which the comparison motion was perceived faster than the reference motion, with the size of the circles indicate the number of trials at each stimulus velocity. The difference between the 50% and 76% levels (dashed lines) is perceptual sigma (grey triangle).
