Investigating the effect of proactive interference control training on intrusive memories

Intrusive re-experiencing is a hallmark symptom of Posttraumatic Stress Disorder (PTSD).According to prominent models of intrusive phenomena, intrusive memories may resultfrom impairments in the efficiency of working memory capacity (WMC), more specificallyproactive interference control. Yet, experimental research is scarce. Therefore, the presentstudy aimed to investigate experimentally the role of proactive interference control inintrusive memories.

We randomly assigned 57 healthy participants to either receive a highinterference control training or a low interference control training. Participants were thenexposed to highly distressing film clips. WMC was assessed before and after the training. Intrusion symptoms were assessed directly post-training and after one week using anIntrusion Provocation Task (IPT), a one-week intrusions diary, and the retrospective intrusionsubscale of the Impact of Event Sale–Revised (IES-R).

Results indicated that both groupsreported improvements in WMC and fewer intrusions on the second IPT post-training, withno differences between groups. Similarly, no group differences on intrusions were found atone-week follow-up (i.e., intrusion diary and IES-R). To conclude, these data are not con-sistent with the hypothesis that WMC plays a role in intrusive re-experiencing. Implicationsfor future research are discussed.