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 normalized difference between the proportion of trials on which the stimulus was perceived as stationary and the proportion of trials on which the stimulus was perceived as moving SPI = (PS − PM)/(PS + PM), for training and test trials.
