Active contextualization reduces traumatic memory intrusions via memory integration

Traumatic memory intrusions, the involuntary retrieval of unwanted memories, significantly impact mental health. The dual representation theory proposes that the origin of intrusion lies in the overactivated sensory memory not being integrated with the corresponding contextual memory, highlighting the crucial associations between memory contextualization and intrusion. To test this, our study investigated whether enhancing memory contextualization could effectively reduce intrusion. After experiencing analogue trauma with the trauma film paradigm, 96 healthy participants were randomly allocated to three intervention groups: active contextualization (AC) in which participants actively retrieve and restructure film content, passive contextualization (PC) in which participants passively restudy content-matched pre-contextualized information, and working memory taxation (WM) in which participants performed a working memory dual-task. Diary recordings over the subsequent week revealed a significant reduction in intrusion frequency in the AC group compared to both the PC group and a no-intervention control group. Furthermore, comparing AC with WM, a well-established laboratory intervention on intrusion, established a superior efficacy of the AC intervention in reducing intrusions. Finally, analyses of the explicitly recollected film memories identified the critical element of active contextualization to be memory integration induced by active memory retrieval. Together, our findings suggest that active contextualization causally diminishes intrusions, providing novel insights into the regulation of the contextual memory system in intrusion intervention.