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.
Single trial of stimulation paradigm. Each trial started with a short reaction task, followed by an anticipation phase of jittered length and stimulation with one of the 4 stimuli: 3 gaseous (ammonia, rose odour and air) or a visual stimulus (rotating checkerboard). At the end of each trial subjects rated stimulus painfulness/intensity and pleasantness on two visual analogue scales (VAS). Abbreviations: ITI, Inter-trial interval
