Ethnic Self-reference Effect:Evidences From Behavior And ERPs

Self-reference effect refers to that performance under self-reference processing task is significantly higher than that of other reference processing or other types of task. This effect was confirmed by lots of previous studies. The present study tried to investigate a new type of self-reference effect--ethnic self-reference effect, and to research the electrophysiological correlates of the processing of ethnic stimulus on the basis of previous researches. Twenty healthy minority university students who lived in the Han region participated for this study as paid volunteers. Minority which participant belongs to was selected as "self-ethnicity", the Han was selected as "compare-ethnicity" and the most familiar minority was selected as "contrast-ethnicity". There was no significant difference among three categories of stimuli in familiarity.There were two experiments in this study. We adopted behavioral and ERP technology to study ethnic self-reference effect at explicit and implicit level, respectively. The first one is a behavioral experiment, we adopted R/K paradigm to investigate ethnic self-reference effect at explicit level with240trait words. The results showed that there was no significant distinction in recognition rate and R/K response between self-ethnicity and Han, but they both were significantly larger than that of contrast-ethnicity. The second one is an ERP experiment, we adopted Oddball paradigm to investigate ethnic self-reference effect at implicit level. Experiment found that on the P2component, self-ethnicity elicited larger P2amplitude at the central-parietal and central sites. On the N2component, the N2amplitude induced by self-ethnicity significantly smaller than that induced by Han and contrast-ethnicity. On the P3component, self-ethnicity elicited larger P3amplitude than the Han at all sites, and the P3amplitude of Han significantly larger than the contrast-ethnicity. Otherwise, Study found that the activation level of the left brain in processing ethnic stimulus significantly higher than the middle and right brain.Experiment1illustrated that reference effects that self-ethnicity and Han have were of the same extent, so there existed no significant ethnic self-reference effect at explicit level. But the results of experiment2showed that the processing advantage of self-ethnicity was found not only in early P2and N2processing stages, but also in late P3processing stage, which illustrated that there existed significant ethnic self-reference effect at implicit level. Finally, this effect represented more prominent in the left brain, indicating that processing upon self-ethnicity is of left brain advantage.