Flipbook

CHAPTER 2 46 Figure 2. Proportion of change in pupil dilations in response to A, B, and C for the Full avoidance condition and Control condition in Experiment 1. Pupil dilation responses are depicted for both conditions together, expect for C*- trials in the Full avoidance condition and C- trials in the Control condition in the Extinction phase. See Table 1 for explanation of trial types. DISCUSSION EXPERIMENT 1 We replicated Lovibond et al. (2009)’s findings for threat expectancy. Presumably, participants in the Full avoidance condition misattributed the nonoccurrence of the loud noise during C trials in the Extinction phase to the full avoidance response. Hence, threat expectancy for C was maintained in the Full avoidance condition, whereas it had decreased in the Control condition. In line with our hypothesis and the findings by Lovibond et al (2009), Experiment 1 showed that safety behavior that prevents the occurrence of threat maintains threat beliefs when safety behavior is no longer available, and may therefore be detrimental to the beneficial effects of exposure. Contrary to our hypothesis, pupil dilation responses did not show associative learning effects. Pupil dilations discriminate most strongly between the CS+ and CS- shortly before US onset (Reinhard & Lachnit, 2002), because the peak pupil response C- C*- A+ A+ A+ A+ A*(+) A~[+] B- B- B- B- C+ C+ C+ 1 1.1 1.2 1.3 1.4 1.5 Pavlovian acquisition Safety behavior acquisition Extinction Test Pupil dilations (proportion change)