Poster B15, Sunday, March 25, 8:00-10:00 am, Exhibit Hall C
Rewarded extinction diminishes enhancement of episodic fear memory
Nicole Keller1, Joseph Dunsmoor1; 1Universirty of Texas at Austin
Defensive behaviors that result from fear conditioning can be extinguished by repeatedly presenting a conditioned stimulus (CS) without its previously paired aversive unconditioned stimulus (US). However, extinction is often followed by the re-emergence of extinguished behavior suggesting that extinction forms a secondary memory of safety that competes with the original fear memory. Previous studies using category-based fear conditioning in humans show that conditioning selectively enhances long-term episodic memory for conditioned exemplars (Dunsmoor et al., 2015; Dunsmoor et al., 2012). In the present study, we examined what happens to episodic fear memory when fear conditioning is followed by a competing experience of reward. Participants were presented with a heterogeneous collection of pictures of animals and tools, and exemplars from one category (CS+; animals or tools, counterbalanced) were reinforced with an electrical shock, whereas objects from another other category (CS-; tools or animals, respectively) were never reinforced. Immediately after fear conditioning, subjects underwent reward extinction (i.e., counterconditioning), in which the shock was unexpectedly replaced with a monetary reward. Subjects returned 24-hours later for a surprise recognition memory test. Preliminary results reveal that a competing reward memory diminishes selective episodic memory enhancement for CS+ items encoded during fear conditioning. This result is stark contrast to past studies (e.g., Dunsmoor et al., 2015), which showed a selective enhancement of fear memory for CS+ objects encoded during fear conditioning. We suggest that rewarded fear extinction may engage an opponent and competing reward system that competes with and inhibits emotional episodic memory enhancements for negative events.
Topic Area: EMOTION & SOCIAL: Emotion-cognition interactions