Figure 2.
Experimental protocols for (a) Experiment 1 (18-week study) and (b) Experiment 2 (four-week study).
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.