Information Processing of the Rorschach's Traumatic Content Index in Trauma-exposed Adults: An Event Related Potential (ERP) Study

- Trauma-exposed and control participants completed oddball distractor paradigms.
- Distractors were phrases derived from the Rorschach's traumatic content index.
- P3 amplitude demonstrated a significant interaction of Group and Distractor type.
- Blood and Anatomy contents were associated with larger P3 amplitude after trauma.
- Blood and Anatomy contents were associated with reduced P3 amplitude among controls.

PTSD elicits hypervigilance to trauma-related stimuli. Our novel research examined event-related potentials from Blood, Anatomy, and Morbid content derived from the Rorschach's traumatic content index (TCI). Participants included: 16 with PTSD, 24 trauma-exposed without PTSD (non-PTSD), and 16 non-traumatized Controls. P3 oddball paradigms were used with TCI-derived Distractors and neutral Targets/Standards. We predicted larger P3 amplitudes in the context of TCI-related Distractors among trauma-exposed participants. Significant interaction of Group and Distractor type was found for P3 amplitude. PTSD and non-PTSD groups exhibited larger P3 amplitudes from Blood and Anatomy Distractors, and attenuated amplitudes from Morbid; the reverse pattern was found among Controls. A late negative component was observed, denoting a significantly larger area under the curve (AUC) among the PTSD group for Anatomy and Blood Distractors. Larger AUC's were observed for Distractors among the PTSD group, and Targets among Controls. The findings concur with the neurocircuitry model of PTSD and suggest impairment in cerebral suppression of attention to stimuli that may have been perceptually primed with trauma.