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.
Breathing signal. Course of a typical breathing signal depicting successive expirations and inspirations. The odor was sent at the beginning of the participant's expiration to ensure odor perception at the beginning of the next inspiration, which occurred approximately 2 s later (in green, period of odor perception, fading with time).
