Devaluation of aversive memories does not reduce intrusions

Background: Neutral stimuli associated with traumatic memory can trigger fear and intrusive memories. Contemporary fear conditioning theory posits that not only extinction learning, but also weakening the intensity of traumatic memory attenuates associated fear and intrusive memories.

Objective: This laboratory experiment tested whether weakening the intensity of aversive memory would reduce conditioned fear and intrusions. Two interventions were compared to a ‘no intervention’ control condition (C). These were laboratory models of imaginal exposure (IE) and the dual-task (DT) procedure used in EMDR (e.g. recalling the traumatic memory and simultaneously making eye movements).

Method: A trauma film paradigm (James et al., 2016) was combined with a fear conditioning task in undergraduate students (N = 76). On day 1, fear acquisition took place in context A with an aversive film. Afterwards, participants were randomly assigned to C, DT or IE. Then, extinction took place in context B. Participants kept an intrusion diary for 48-hours. On day 3, they were presented with context A again to trigger fear. Results: Fear acquisition and extinction were successful. DT and IE decreased unpleasantness of aversive memory compared to C, F(2, 73) = 4.18, p = .02, ƞp2 = .10, but not frequency and quality of intrusions or conditioned fear.

Conclusions: Unpleasantness of aversive memory decreased similarly after DT and IE, which suggests that eye movements did not contribute over and above mere recall. However, this did not affect conditioned fear or intrusions. Theoretical and practical implications of the findings will be discussed.