Timing matters: Providing Contingency Instructions to modify Fear Extinction Memories in Anxiety Disorders

Previous research suggests that contingency instructions (CI), stating that the unconditioned stimulus (UCS) will not be presented anymore, can enhance extinction learning, and additional CI before extinction retrieval can reduce the return of fear. However, immediate pre-retrieval instructions are impractical in therapeutic settings. Thus, this study investigated the impact of CI before and/or after extinction training on extinction learning in 240 participants (120 patients with anxiety disorders (ADs), 120 healthy controls) using a three-day sequential conditioning paradigm. Electrical shocks and colored lamps served as UCS and conditioned stimuli (CS), with skin conductance responses (SCRs), CS valence, and UCS expectancy ratings as readout measures. CI before extinction training enhanced extinction learning for both patients with ADs and healthy controls across the physiological and subjective measures. Instructed healthy controls displayed even lower SCRs than instructed patients during early extinction. Furthermore, participants receiving post-extinction CI showed reduced CS differentiation in their SCRs during extinction retrieval. After a reinstatement, instruction timing differentially affected fear responses across contexts. Participants instructed before and after extinction, and uninstructed participants showed higher fear responses in the original conditioning context. Those instructed only before extinction exhibited increased fear responses in extinction and novel contexts, while participants instructed only after extinction showed heightened fear responses exclusively in the extinction context. The findings highlight how the timing of providing contingency information shapes fear learning and memory.