Figure 4.

Behavioral results for day 2 inside the scanner. A, Mean number of squeezes as a function of trials over time during the PIT test. The first 10 trials consisted of a reminder (Rem.) of the instrumental contingencies and a partial extinction (Part. Ext.); the rest of the trials consisted of the actual PIT test for which the number of squeezes is depicted separately for the conditioned stimulus previously associated with the olfactory reward (CS+) and the conditioned stimulus previously paired with odorless air (CS−). B, Overall mean number of squeezes while the CS+ or the CS− was presented during the PIT test. C, Mean perceived pleasantness ratings as a function of trials over time depicted separately for the rewarding and the neutral odors during the hedonic reactivity task. D, Overall mean perceived pleasantness of the rewarding and the neutral odors. Pleasantness was evaluated on a scale from 0 (extremely unpleasant) to 100 (extremely pleasant). Error bars indicate ±1 SEM, adjusted for within-participants designs. Asterisks indicate statistically significant differences between conditions (***p < 0.001).