Flipbook

CHAPTER 2 48 EXPERIMENT 2 Experiment 2 entailed the same basic design as Experiment 1 with several improvements, to investigate whether safety behavior that allows the occurrence of threat prevents extinction. First, we simplified and clarified the oral and written instructions based on pilot studies. Second, after receiving the oral instructions from the experimenter, participants were asked to explain the experimental task in their own words to check if they had understood the instructions correctly. Third, participants were told that the full avoidance response prevented a possible subsequent loud noise, and that the subtle safety behavior reduced the volume of a possible subsequent loud noise. Fourth, the availability of the full avoidance response and subtle safety behavior was not indicated by a picture of a plug and a picture of headphones that were presented simultaneously with the CS, to prevent that these pictures might function as negative occasion setters. Instead, during full avoidance and subtle safety behavior trials an instruction screen preceded CS presentation to inform participants that they could unplug or take off the headphones, respectively. Fifth, to further prevent that the full avoidance response and subtle safety behavior may function as negative occasion setters, the full avoidance response and subtle safety behavior were learned during two A and two C trials in the Safety behavior acquisition phase, instead of during four A trials in Experiment 1 (see Table 2). Hence, in Experiment 2, stimulus C was not exclusively combined with the full avoidance response and subtle safety behavior on unreinforced presentations, but also on reinforced trials. We hypothesized that we would replicate the findings of Experiment 1 and Lovibond et al. (2009), as evidenced by higher threat expectancy for C in the Test phase in the Full avoidance condition than in the Subtle safety behavior and Control condition. Furthermore, we hypothesized that using subtle safety behavior during unreinforced C trials would not prevent extinction learning for C. To be precise, we