Negative Situations Induced Depression Emotional Bias Students: An ERP Study

Depression disorder is a kind of affective disorder. It is characterized by low mood, attenuated emotional reactivity to positive stimuli. The cognitive theories and cognitive vulnerability concept of depression suggested that the depressed peoples’ depressive schemas that lay dormant until activated by life stressor, they will arise a negativity bias. So what event-related potentials differences between normal people and depressed people will occur after suffering the stressor that produces negative emotion?By using the event-related potentials (ERP) technology, we tested the negativity bias differences between the normal people and depressed people in performance of emotional Stroop task after neutral and negative emotion induction procedures with EGI portable EEG recorder. Participants were university students grouped according to their BDI scores:non-depressed controls and depressed participants. The two groups watched the neutral and negative film editing successively in order to inducing neutral and negative emotion respectively. Before and after inducing, the subjects completed the subject emotion evaluation, then the subjects completed the emotional Stroop task that chosen the positive, negative and neutral words from CAWS. The results suggested that the emotional induction procedure elicited the emotion that need in the experiment successfully. In behavioral data, there were no differences between the behavioral data of the two groups; the ERPs data reflected The two groups didn’t have differences among the positive, negative and neutral words in negative emotion inducing, the depressed subjects still had normal mental function. The two groups didn’t have differences among the positive, negative and neutral words in neutral emotion inducing, the result had proven the cognitive vulnerability. The P1amplitude of negative words had significantly differences between two Stroop task in normal subjects, the neutral P1was more bigger. N1amplitude of negative words had significantly differences between two Stroop task in normal subjects, the negative N1was more bigger. These experiment results suggested when processing negative words, the normal subjects could use emotion regulation effectively after negative emotion inducing in order to reduce the adverse effect that induced by the emotion inducing; but it wasn’t find in depressed group, so it was illustrated that the depressed couldn’t use emotion regulation effectively after going through negative emotion, so processing the negative words exerted an badly influence. Although the subjects participated in experiment was depressed, but they remain belonged to normal people, the mental function was normal, but they couldn’t execute normal regulation after negative emotion.