The Effect Of Reward Cue On Self-face Recognition Advantage:Evidences From ERPs

Recently,’Self’ and ’Reward’ are always the issues of psychological researches, and the question on ’Is our self based on reward?’ has received the earnest attention of psychologists. Based on previous researches, the money and face stimulus were used in this study to explore how (un)consciously high and low reward cue affect the self-face recognition advantage by event-related potential technology. Furthermore, the present study was aimed to understand the complex relationship between Self-relatedness and reward at an electrophysiological level.There were two experiments in this study. The experiment 1 revealed how reward cue influenced the self-face recognition advantage by using the reward cue paradigm and implicit self-face recognition task. In experiment 1, RMB 100 Yuan(vs. the blank paper of same size) was used to induce reward motivation primarily, and then event-related brain potentials were recorded when participants were judging the orientation of the different faces (self face, friend face, and strange face). The experiment 2 explored how (un)consciously reward cue affect the self-face recognition advantage. In experiment 2, RMB 100 Yuan (vs.20 Yuan) were (un)consciously presented to induce reward motivation primarily, and event-related brain potentials were recorded when participants were judging the consistency of the former’s and the latter’s mouth shapes.The experiment 1 showed there was an interaction between Self-relatedness and reward cue in the later stage of self-face recognition. Compared to friend and strange face, reward cue promoted self face to induce larger P3 and LPP(450-600ms) average amplitude. Firstly, the experiment 2 found an interaction in ERP waveforms in the N2 component between Self-relatedness and reward value, with larger N2 average amplitude for self face in the high reward cue compared to friend and strange face. Secondly, there was an interaction in ERP waveforms in the P3 component among Self-relatedness, reward presentation and reward value, with larger P3 average amplitude for self face in the consciously high reward cue compared to friend and strange face. Thirdly, there was an interaction in ERP waveforms in the LPP(400-550ms) component between Self-relatedness and reward presentation, with larger LPP (400-550ms) average amplitude for self face in the consciously reward cue compared to friend and strange face.The results supported the processing of Self-relatedness and reward are closely associated, and confirmed reward cue could effectively promote the self-face recognition advantage. Moreover, this promotion shows a specific temporal feature. In the early stage of self-face recognition, there isn’t an interaction between Self-relatedness and reward. However, similar to reward value, Self-relatedness with reward presentation synergistic ally effects self-face recognition. Importantly, reward presentation moderates the effect of reward value on the processing of Self-relatedness in self-face recognition.