“…For example, variability in the contexts and stimuli used during extinction training, which can produce a less context or stimulus-specific extinction memory, has been shown to attenuate renewal following laboratory extinction training [62,63,64] and exposure therapy with specific phobias [65,66,67]. Further, the use of a retrieval cue, which is a neutral stimulus present during extinction that can later enhance retrieval of the extinction memory, has shown promise in reducing return of fear in both laboratory [68,69,70] and clinical studies [71,72].…”