A dual-retrieval-mode extinction procedure reduces fear renewal

A key limitation of exposure therapy is the return of fear after extinction. We drew on the memory-modulating benefits of selective retrieval and the learning-enhancing effects of variability to develop a novel dual-retrieval-mode extinction procedure. Forty-eight participants completed a four-day differential fear-conditioning paradigm comprising acquisition (60% reinforcement rate), two extinction sessions, and a renewal test. During the extinction phases, participants in the dual-retrieval group alternated between standard US-expectancy ratings (unrestricted retrieval) and safe/dangerous judgments in line with the outcome of the most recent CS+/CS- trial (restricted retrieval), whereas the control group completed standard expectancy ratings throughout extinction. Conditioned responding was assessed using skin conductance responses and subjective measures, including US expectancy, valence, and arousal ratings. Both physiological and subjective indices indicated that the dual-retrieval group exhibited reduced fear renewal relative to the control group. During extinction this group had shown larger skin conductance responses and higher US expectancy than the control group, but comparable arousal and valence ratings suggest this reflects reduced within-session habituation rather than stronger inhibitory learning. Because differential responding persisted, the benefit reflects enhanced competitive strength of the extinction memory rather than erasure of the fear memory. Manipulating retrieval demands during extinction may represent a promising strategy for reducing the fragility and context-dependence of extinction learning.