اثر سرکوب افکار و بار شناختی بر روی نفوذ و فرآیندهای حافظه پس از عوامل استرس زای آنالوگ

Ironic Process Theory and the role of thought suppression have been used in part to explain the phenomenon of intrusive memories in various disorders, including posttraumatic stress disorder. How thought suppression interacts with other cognitive processes believed to be instrumental in the development of traumatic intrusive memory is unclear. In an analogue study, thought suppression and cognitive processing was manipulated in 4 experimental groups after participants (n = 80) viewed a trauma film. The impact of suppression was examined in relation to self-reported intrusive experiences as well as via more objective methods (word stem and dot probe tasks) to assess potential preferential encoding of negative material. Cognitive load appeared to undermine thought suppression ability, with these participants experiencing more intrusions over the week relative to participants in all other conditions. This group also showed greater priming to negative film-related words, and both suppression groups demonstrated enhanced memory for film-related content on recognition testing. Thought suppression mediated the relationship between negative interpretations of initial intrusions and later intrusions experienced over the week. The findings are discussed in the context of ironic process theory and cognitive models of posttraumatic stress.

There were no significant differences in potential correlates, nor did groups differ in terms of distress caused by the film, attention paid to the film, etc., and therefore these peripheral variables are not reported due to space limitations. In line with experimental instructions, the Suppression and Cognitive Load group reported higher suppression effort than the Cognitive Load Only and Control groups (p’s < .05), and the Suppression Only group similarly reported more suppression effort than the Control group (p = .03). The Suppression Only group's greater suppression effort than the Cognitive Load Only group fell just short of significance (p = .06). Accuracy of recall of the 9-digit number for participants in the Suppression and Cognitive Load and Cognitive Load Only groups was reasonable, with 65% and 60%, respectively, recalling the number string in the correct order. For the remaining participants, their errors were relatively minor. Immediate and Follow-up Intrusions During 5-Min Monitoring Periods Intrusion frequency and duration were analysed with analyses of variance (ANOVAs) using a Group (4: Suppression and Cognitive Load, Suppression only, Cognitive Load only, Control) × Time (2: Immediate, Follow-up) design, with repeated measures on the second factor. Significant effects were followed up with planned pairwise comparisons. In terms of frequency of intrusions, there was not a main effect of group, nor a significant interaction (see Table 1). Overall, participants reported significantly more intrusions in the first testing session relative to the second. Analysis of intrusion duration revealed the same pattern of findings (see Table 1).