Negative implicit in-group stereotypes of Chinese male drug abusers: evidence from ERP.

Psychological dependence is the most important factor leading to relapse, few studies have examined whether in-group stereotypes exist in drug abusers, while it's helpful for drug abusers in getting rid of psychological dependence. To investigate the presence of in-group stereotypes and the neural mechanisms in drug abusers, two experiments were designed in this study. Experiment 1 used a classification-verification paradigm and Experiment 2 used The Extrinsic Affect Simon Task (EAST), simultaneous collection of EEG data from China. 18 and 17 males were analyzed respectively in Experiment 1 and 2. The results in Experiment 1 showed that (1) there was no significant difference in reaction times or N400 amplitude between the condition "Drug abusers-Negative words" and the condition "Drug abusers-Positive words". In Experiment 2, we found that (2) participants in the condition "Drug abusers-Negative words" scored higher in accuracy rates than in the condition "Drug abusers-Positive words". (3) Participants in the condition "Drug abusers-Negative words" were shorter than "Drug abusers-Positive words" in reaction times (RTs). (4) Participants in the condition "Drug abusers-Negative words" were lower than "Drug abusers-Positive words" in the peak of N400. The conclusion is that there are significant negative implicit in-group stereotypes among Chinese male drug abusers. The experimental results and the uniqueness of Chinese male drug abusers in this study were discussed.