A 32-year-old male military veteran with combat-related PTSD has been avoidant of all trauma-related stimuli for three years. He avoids conversations about his deployment, refuses to drive past the military base, and has not worn his uniform since discharge. His PMHNP refers him for prolonged exposure (PE) therapy. After psychoeducation and breathing retraining, the therapist begins imaginal exposure in which the veteran recounts his index trauma in vivid detail with eyes closed, narrating in the present tense for 45 to 60 minutes while the therapist monitors his Subjective Units of Distress. Which of the following best describes the theoretical mechanism by which PE is expected to reduce this patient's PTSD symptoms?