Fig. 2.

Fear Potentiated Startle Testing Procedures. Day 1 of testing (Fear/Safety Learning) included 8 presentations of the CS+ (blue circle), paired with an air puff to the throat 75% of the time. Day 1 also included 8 presentations of the CS- without being paired with the air puff, and 8 Noise Alone (NA) trials. Day 2 (Extinction Learning) included 16 presentations of the CS+, 16 presentations of the CS-, and 16 NA trials. No air puffs were administered during this session. Day 3 (Extinction Recall) included 8 CS+, 8 CS-, and 8 NA trials. As on the day before, no air puffs were administered. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)