| Popis: |
Study objectives: Following traumatic events, people frequently experience distressing, involuntary memories of them (i.e., intrusions). Accumulating evidence suggests that sleep facilitates voluntary memory retrieval by supporting memory consolidation, but it is less clear what effect sleep has on intrusions. Recent research has used distressing film clips as a proxy for traumatizing events and examined whether sleep affects intrusions by prompting participants to record diaries of intrusions across several days after viewing the trauma film. We sought to synthesize the literature on sleep and intrusions by performing a meta-analysis.Methods: A total of 7 effect sizes from 6 independent studies were included in two meta-analyses examining the effect of sleep (n=192) compared to wake (n=175) on a) the number of intrusions and b) the mean distress associated with them. Results: There was a small significant effect where sleep reduced the number of intrusive memories (Hedges’ g = -0.26, p = .04, 95% CI [-0.50, -0.01]). Sleep did not significantly affect the average distress associated with intrusions (Hedges’ g = -0.14, p = .25, 95% CI [-0.38, 0.10]).Conclusions: Although sleep appears to reduce the number of intrusive memories of distressing films, high-powered studies are needed to examine the reproducibility of this effect. We discuss to which extent this effect is caused by sleep affecting the consolidation of these memories, and to which extent sleep simply makes it easier to consciously control which memories enter into awareness. |
