This study aimed to investigate the relationship between behavioral and event rerated brain potentials. Based on (GAIN/LOSS bet) x (higher and lower competitive achievement motivation groups), the following five hypotheses were tested: a) MFN amplitude for result stimuli does not show any difference between at GAIN and at LOSS, b) P3 amplitude at LOSS is larger than at GAIN, c) P3 amplitude for result stimuli is larger on higher group than on lower group, d) P3 peak latency is shorter on higher group than on lower group, e) Higher group gets higher GAIN rates as they continue to attempt, and gets more GAINs in total than lower group. Our experimental results supported all of these hypotheses.