An ERP Study Of The Influence Of Emotion On Cognitive Control In Earthquake Survivors

After the great Sichuan earthquake (China) on May 12 (5/12),2008, many people had long-term problems. These included obsession with the trauma, nightmares, flashbacks, emotional numbing, and loss of interest in life, irritability, memory problems, and hypervigilance. Previous studies mainly focused on post traumatic stress disorder. However, there has been very little work examining the neural correlates of trauma exposure in people without a clinical disorder. Therefore, in experiment one, we used the classic Stroop task to explore how personal earthquake experience (Far and Close earthquake experience) impacts on their cognitive control. In experiment two, we used the emotional Stroop task to study how emotional information influenced the cognitive control in the earthquake group (trauma exposed non-pathology sample). We wanted to provide experimental evidence and theoretical guidance for psychological crisis intervention and treatment.The results of experiment one exhibited robust behavioral and electrophysiological effects in the Chengdu group performing the Chinese characters Stroop task, Incongruent stimuli elicited a more negative ERP deflection (N400-600) than did congruent stimuli between 400-600 ms post-stimulus over fronto-central scalp regions in the Chengdu group, and Stroop interference ERP effect was not found in the Deyang group, which had greater direct personal experience of the great Sichuan earthquake. We therefore suggested that the anterior systems of executive control focused on the PFC and the ACC that monitor and control cognitive conflict might be deactivated in the Deyang group. The results of experiment two demonstrated that Negative words elicited a decreased P2 ERP component than did Positive words in the earthquake group. Moreover, Negative words also elicited a more negative ERP deflection (N280-380) than did Positive words between 280-380 ms post-stimulus in the earthquake group. The results might suggest that individuals have a special sensitivity and emotional arousal by negative emotional stimuli due to their experience of a recent traumatic event. The results suggested that earthquake survivors might be automatically disturbed by the negative information during the emotion Stroop task performance.