An ERP Study Of Other-race Effect: Recognition Potential Effect

There is no doubt that face recognition plays an important role in our daily life, since it can provide us lots of information, such as race, gender, age, and expression. Face recognition has become a hot topic especially with the increasingly frequent international exchange. It has been found that people are good at recognizing their own race than other race faces, with higher accuracy and less reaction time. This phenomenon is called other-race effect. Other-race effect has been well documented in behavior and neurophysiological research. However, it is yet unclear at the present time on neural mechanism of other race effect.Studies have found that EEG response which was evoked at about 200ms reflects other-race effect. Recognition potential, due to its time window and the paradigm advantages, can help to answer other-race effect with certain feasibility. RP (short for recognition potential) is an electrical response of the brain peaking around 200 to 250ms after stimuli onset and obtained when subjects view recognizable and attended stimuli, such as words or pictures. In this paper, we regard recognition potential as an index to explore the cognitive mechanism of other-race effect. Here we conduct two experiments by using Rapid Stream Stimulation (RSS, Rudell,1992) paradigm, the topic paradigm to study recognition potential. To investigate the time course of processing other-race faces, ERP (event-related potential) were recorded in response to Chinese faces and Caucasian faces on Chinese subjects.In experiment 1, Chinese subjects were asked to judge whether the target picture was Chinese face or Caucasian face. The results revealed a significant main effect of race for RP amplitude, suggesting different neural activity between own race and other race faces. Experiment 2 was an orientation judgment task—an irrelevant task to race classification. And the results showed no difference on race but on orientation.To sum up, we found that reaction time and RP amplitude, mainly for the upright faces were affected by different tasks. Our results indicate that RP may reflect the neural mechanism of other-race effect.