Fig. 1
The main part of (a) illustrates the design of the experiment with each of the rows representing each of the five conditions or types of cues (A–H) presented on screen in each phase, with columns showing each phase. The first day of testing comprised of conditioning and two extinction phases. During conditioning, cues were paired with an electric shock (fear), an erotic image (reward), scrambled pixels (no-reward), or a no-shock sign (no-fear). In single extinction, cues were presented individually with no outcome (no-fear or no-reward), and in deepened extinction, cues were presented either individually (solo conditions: A, H), or simultaneously with another cue (deepened conditions: BC, DE, FG), all with no outcomes (no-shock sign). A week later, participants were given reextinction and reinstatement phases. To induce return of fear, electric shocks were given randomly before the reinstatement phase. This same design was used across two independent studies, where the first measured only skin conductance responses, and the second collected behavioral and neural data, with subjective ratings of pleasantness and fMRI, respectively. The figure shows in the top left-hand corner of (a) the 2 × 2 nature of the presence or absence of appetitive (reward) and aversive (shock) outcomes, and in the main box, all the cues that represented each of the conditions (2 experimental deepened extinction and 3 control “(C)” conditions) and the different testing phases spread over a week of testing; and (b) shows examples of stimuli presented on screen for each phase, and (c) shows an example of the visual analogue scale used to rate subjective pleasantness of cues in the MRI scanner in the second sample.
