Proactive Interference in Posttraumatic Stress Disorder

Deficits in working memory (WM) have a role in maintaining posttraumatic stress disorder (PTSD) symptoms, including intrusions, which are a hallmark of PTSD symptomatology. As intrusions are distressing and uncontrollable, it is important to investigate whether PTSD is associated with altered control of proactive interference in WM. Moreover, it is important to consider both verbal and visual WM, as previous research has demonstrated a visual versus verbal dissociation in PTSD. Although previous studies have explored proactive interference in visual and verbal stimuli using a recent probe task, the stimuli used thus far have been non-trauma-related. Therefore, we aimed to investigate proactive interference in PTSD using trauma-related verbal and visual stimuli. Road traffic accident (RTA) survivors with (n = 60) and without PTSD (n = 30) completed a recent probe task to assess proactive interference of visual and verbal trauma-related material. Participants with PTSD displayed significantly more proactive interference than trauma-exposed controls for visual, η_p ² = .40, and verbal material, η_p ² = .10, indicating that proactive interference is significantly impaired in PTSD. This demonstrates that further research is warranted and highlights the possibility of considering proactive interference of trauma-related stimuli in therapeutic approaches.