Visuospatial computer game play after memory reminder delivered three days after a traumatic film reduces the number of intrusive memories of the experimental trauma

Objective: The experience of intrusive memories is a core clinical symptom of posttraumatic stress disorder (PTSD), and can be distressing in its own right. Notions of dual task interference and reconsolidation-update mechanisms suggest novel approaches to target intrusive memories. This study tested the hypothesis that a single-session cognitive intervention (memory reminder task plus Tetris gameplay) would reduce the occurrence of experimental trauma memories even when delivered 3 days post-trauma. Critically, this study tested effects against two control groups: Reminder-only, and reminder plus another computer game (a form of Quiz). Methods: 86 healthy volunteers (59% female, age M = 24.35, SD = 4.59 years) watched a trauma film and then recorded their intrusive memories in a diary for 3 days (pre-intervention). They then returned to the lab. After presentation of visual reminder cues for the film plus a 10 min wait period (memory reminder task), participants were randomized into one of three task conditions (Tetris game play, Quiz game play, vs. reminder-only). They then kept the diary for a further 3 days (post-intervention). Results: As predicted, after the experimental manipulation, the reminder + Tetris group experienced significantly fewer intrusions than the reminder-only group (d = 1.37). Further, the reminder + Tetris group also experienced significantly fewer intrusions than the reminder + Quiz (d = 0.65) group. Contrary to predictions, the reminder + Quiz group experienced significantly fewer intrusions than the reminder-only group (d = 0.69). Prior to the experimental manipulation, there was no significant difference between groups in number of intrusions. Recognition memory test scores for facts of the trauma film after 6 days were comparable between groups. Conclusions: We demonstrated that 3 days after experimental trauma (i.e. after memory consolidation) an intervention comprising a reminder task prior to a 15 min cognitive interference task (one of two computer games) led to a reduction in intrusion occurrence compared to reminder only. We interpret and discuss our findings within the framework of supposed reconsolidation-update mechanisms and competition for limited (visuospatial) working memory resources. Should these effects hold true in clinical populations, this type of simple intervention approach could help contribute to reducing intrusive memories of trauma.