Alteration of early attentional processing after analogue trauma exposure: evidence from event-related potentials

The present study aimed to determine whether exposure to an analogue traumatic event affects attentional processing of emotional information. Two groups of non-clinical participants matched on anxiety level, depression symptoms and stressful life events viewed either a trauma or a neutral film. They then performed an emotional Stroop task during which both continuous electroencephalographic activity was recorded and intrusive memories were measured. Results revealed that the valence effect (measured by the difference between emotional and neutral conditions) for the P1 amplitude was significantly greater in participants who viewed the trauma film than in participants who viewed the neutral film. This interaction was specific to words semantically related to the analogue trauma event and did not extend to all negative words. Further analyses revealed a relationship between intrusions frequency, P1 amplitude and emotional Stroop interference, indicating a link between attention and intrusive memories. Our findings suggest that exposure to potentially traumatic events has an important impact on neurocognitive function, even in the absence of psychopathology, and that this impact occurs at an early, possibly automatic stage of processing.