Self-report may underestimate trauma intrusions.

Research examining maladaptive responses to trauma routinely relies on spontaneous self-report to index intrusive thoughts, which assumes people accurately recognize and report their intrusive thoughts. However, "mind-wandering" research reveals people are not always meta-aware of their thought content: they often fail to notice shifts in their attention. In two experiments, we exposed subjects to trauma films, then instructed them to report intrusive thoughts during an unrelated reading task. Intermittently, we asked whether they were thinking about the trauma. As expected, subjects often spontaneously reported intrusive thoughts. However, they were also "caught" engaging in unreported trauma-oriented thoughts. The presence and frequency of intermittent probes did not influence self-caught intrusions. Both self-caught and probe-caught intrusions were related to an existing tendency toward intrusive cognition, film-related distress, and thought suppression attempts. Our data suggest people may lack meta-awareness of trauma-related thoughts, which has implications for theory, research and treatment relating to trauma-related psychopathology.