Intrusions in posttraumatic stress disorder (PTSD) are clinically understood as conditioned responses (CRs) to trauma-cues; however, experimental evidence for this is limited. We subjected 84 healthy participants to a differential conditioned-intrusion paradigm, where neutral faces served as conditioned stimuli (CS) and aversive film clips as unconditioned stimuli (US). While one group only completed acquisition, another group additionally received extinction. Subsequently, participants provided detailed e-diary intrusion reports. Several key findings emerged: First, participants in both groups re-experienced not only US but also CS as content of their intrusions. Second, intrusions were triggered by stimuli resembling CS, US, and experimental context. Third, extinction reduced probability and severity of US intrusions, and accelerated their decay, and this was particularly the case in participants showing greater cognitive (US-expectancy) and physiological (SCR) differential responding to CS+ vs. CS- at end of acquisition (i.e., conditionability). Similarly, CS-intrusion probability and severity was reduced by extinction in participants with greater cognitive conditionability. These results support conditioning’s role in re-experiencing in two critical ways: (1) Conditioning during trauma provides cues that not only function as triggers, but also as content of intrusions; (2) After strong conditioning, weakening the original CS-US relationship via extinction prevents intrusion formation after analogue-trauma.
“Why” or “How”: The Effect of Concrete Versus Abstract Processing on Intrusive Memories Following Analogue Trauma