Two fear-conditioning tasks were completed: the screaming lady task and the novel bell task. Details on the screaming lady task were described previously (e.g., [1 ]). The bell task follows the same conditioning procedures as the screaming lady task, but uses distinct audio and visual stimuli. Specifically, the CS+ and CS- are pictures of blue and yellow bells, instead of pictures of two women’s faces, and the UCS is an aversive bell sound instead of a scream. The UCS consisted of a 1-s image of a red bell co-occurring with an aversive 95 dB alarm (see Fig. 1 ). These are corollaries of the fear expression and scream used as UCS in the screaming lady task. Participants completed each task on a separate visit, with at least 3 days between the two visits (Mdays between tasks = 25.64, SD = 7.60). The order of the two procedures (screaming lady or bell task) was randomly determined.
In both tasks, the stimuli used for the CS+ and CS- were counterbalanced across participants. The CS+ and the CS- were presented for 7-8 s followed by a gray screen (intertrial interval; ITI) presented for 8-21 s (averaging 15 s). The CS+ was followed by the UCS according to an 80% reinforcement schedule. Air puffs (4-10 psi of compressed air for 40 ms) were delivered to the forehead during the CS+, CS-, and ITI to measure FPS. Startle probes were delivered 5-6 s after CS onset to allow for measurement of SCR during the first 5 s of the trial.
The fear-conditioning tasks consisted of four different phases— habituation, preconditioning, fear conditioning, and extinction. In each phase, the CS+, CS-, and ITI were presented in different blocked counterbalanced order. Before the first phase, participants were told that they might see unpleasant pictures, hear unpleasant sounds, and feel an air puff on their forehead. They were also told that if they paid attention they may learn to predict when the sound will occur, but they were not informed of the UCS/CS+coupling.
During habituation, six startle probes without any visual stimuli were delivered. In the preconditioning phase, images of the CS+ and the CS- were presented four times each. During the fear-conditioning phase, images of the CS+ and CS- were presented 10 times each. The UCS was delivered eight times while paired with the CS+. Finally, in the extinction phase, the CS+ and the CS-were each presented eight times in the absence of the UCS.
Participants reported their levels of fear while viewing the CS+ and CS- using a 10-point Likert scale (1 = non, 10 = extreme) during preconditioning, and immediately following fear conditioning and extinction.
In both tasks, the stimuli used for the CS+ and CS- were counterbalanced across participants. The CS+ and the CS- were presented for 7-8 s followed by a gray screen (intertrial interval; ITI) presented for 8-21 s (averaging 15 s). The CS+ was followed by the UCS according to an 80% reinforcement schedule. Air puffs (4-10 psi of compressed air for 40 ms) were delivered to the forehead during the CS+, CS-, and ITI to measure FPS. Startle probes were delivered 5-6 s after CS onset to allow for measurement of SCR during the first 5 s of the trial.
The fear-conditioning tasks consisted of four different phases— habituation, preconditioning, fear conditioning, and extinction. In each phase, the CS+, CS-, and ITI were presented in different blocked counterbalanced order. Before the first phase, participants were told that they might see unpleasant pictures, hear unpleasant sounds, and feel an air puff on their forehead. They were also told that if they paid attention they may learn to predict when the sound will occur, but they were not informed of the UCS/CS+coupling.
During habituation, six startle probes without any visual stimuli were delivered. In the preconditioning phase, images of the CS+ and the CS- were presented four times each. During the fear-conditioning phase, images of the CS+ and CS- were presented 10 times each. The UCS was delivered eight times while paired with the CS+. Finally, in the extinction phase, the CS+ and the CS-were each presented eight times in the absence of the UCS.
Participants reported their levels of fear while viewing the CS+ and CS- using a 10-point Likert scale (1 = non, 10 = extreme) during preconditioning, and immediately following fear conditioning and extinction.
