Our investigation deals with high interindividual variability of Event-Related-Potentials (ERP). We tried to find out systematic causes of these variability. In a performance situation 36 Ss were asked to solve arithmetical tasks. They got a weak electric shock applied at one finger when the result was wrong (negative feedback), at another finger when it was correct (positive feedback). The electrical stimulus triggered the ERPs. Special personality characteristics related to "need-achievement" (processing of success and failure) "and anxiety" had influence upon ERPs. We found various differences between ERPs following positive as well as negative feedback (success and failure) that point to the suggestion that there exist differences in processing feedback information in persons with different personality traits mentioned above.