Participants
Anxiety, anxiety, pain
RECRUITMENT
We recruited 101 participants from the general population between November 5, 2019 and December 22, 2020 and randomly assigned them to placebo (Sample characteristicsUS intensity: electric current used in experiment; pain ratings pre vs post: difference in average pain ratings of 14 stimuli before and after the acquisition test; accuracy: % of correct responses in identification task, average of acquisition (visit 2) and recall (visit 3); performance: % of responses in identification task, average of acquisition (visit 2) and recall (visit 3); arousal: difference in arousal ratings between CS+/CS− after the acquisition session (visit 2), and after the recall session (visit 3); valence: difference in valence ratings between CS+/CS− after the acquisition session (visit 2), and after the recall session (visit 3); state anxiety: measured with State-Trait Anxiety Inventory (STAI; The study was conducted in accordance with the Declaration of Helsinki and approved by the governmental research ethics committee (Kantonale Ethikkomission Zürich KEK-ZH-2018–01973) and the Swiss Agency for Therapeutic Products (Swissmedic; 2019DR1026). All participants gave written informed consent before the experiment using a form approved by the ethics committee. The study was preregistered with a WHO-approved primary registry (German Clinical Trials Register, DRKS00017037) and at the Swiss Federal Complementary Database (Kofam: SNCTP000003485). During recruitment, the analysis protocol was adapted based on ongoing methodological work (