Flipbook

CHAPTER 2 42 After finishing the experimental task, participants filled out the questionnaire about contingencies and pleasantness. Next, they were debriefed and given their reward. Scoring and analysis Pupil data were preprocessed by interpolating blinks via Mathôt's (2013) method, and then dividing the pupil signal from 0 - 5000 ms after CS onset by the median pupil size during a baseline period of 200 ms before CS onset. The maximum value of the pupil trace in this 0 - 5000 ms period was used for further analysis. Fear acquisition had to take place to allow drawing conclusions about fear extinction (see Lonsdorf et al., 2017). Therefore, participants who did not show contingency awareness were excluded from the analyses (Lovibond & Shanks, 2002). Contingency awareness was defined as a higher threat expectancy for A and C than for B on the final trial of the Pavlovian acquisition phase, and correctly indicating which CS were followed by the loud noise on the contingencies questionnaire after the experimental task. Analyses were performed on data with and without replaced outliers. Outliers were defined as more than 3 SD from the mean, and were replaced with M ± 3 SD . Replacing outliers did not affect the direction of the main findings. We therefore reported the analyses that were performed on the original data. The data were analyzed with mixed ANOVAs (α = .05), comparing threat expectancy and pupil dilation responses between Stimuli (A vs. B vs. C) and Conditions (Full avoidance vs. Control). Corrected values were reported in case the assumption of sphericity was violated. Planned comparisons were conducted with paired and independent t -tests. RESULTS Participants Data were not collected for three participants due to malfunctioning of the task. Three participants did not show contingency awareness after the Pavlovian