Conditioned responses to trauma reminders: How durable are they over time and does memory integration reduce them?

- Trauma-associated sounds elicit intrusive memories and anxiety after trauma film.
- Conditioned intrusive memories are stable over one week.
- Enhanced conditionability predicts subsequent ambulatory trauma intrusions.

Background and objectivesStimuli associated with the trauma are important triggers for intrusive memories after a traumatic event. Clinical models assume that fear conditioning for neutral stimuli encountered during traumatic events is a potential cause of these intrusions, and that memory integration has the effect of reducing these associations, thereby also reducing intrusions. This study examines whether conditioned associations lead to intrusive trauma memories and how they are affected by memory integration.MethodsForty-eight healthy participants watched a neutral and a “traumatic” film, both containing neutral sounds, and, on the following day, were randomly allocated to memory integration of either the “traumatic” film or the neutral film. Intrusive memories were monitored for one week. Participants repeatedly completed a memory triggering task, in order to assess how durable conditioned intrusive memories are over time.ResultsTrauma-associated sounds elicited intrusive memories and anxiety when encountered directly after film presentation, as well as one and seven days later. Furthermore, enhanced conditionability predicted subsequent ambulatory trauma intrusions. No evidence was found for the assumption that memory integration of the “traumatic” film reduced conditioned reactions.LimitationsThe presented film is a relatively mild stressor as compared to a real-life trauma. Further studies are needed to explore the role of conditioned intrusions for real-life trauma.ConclusionsThis study provides evidence for the assumption that intrusive trauma memories can be explained by conditioned responses to neutral stimuli encountered during the trauma and that these effects are stable over time. Implications for PTSD and its treatment are discussed.