ERP investigations of error monitoring: Performance, motivation and personality effects on the error-related negativity

In this thesis, the error-related negativity (ERN; or error negativity; Ne) is investigated. The ERN is an ERP component that is typically observed following erroneous responses. Although it seems to be a robust phenomenon, its psychological significance and relation to everyday behaviour are still not clear. One account suggests the ERN reflects a mismatch between expected and actual outcomes, leading to "error detection". Chapter 2 describes a series of experiments that were conducted to examine the effects of uncertainty for error monitoring, and to assess the accountability of the error-detection hypothesis. In the first study, 18 university students completed letter discrimination tasks during single- and dual-attention conditions designed to manipulate response certainty. In the second study, the same participants completed easy and difficult tone discrimination tasks designed to influence stimulus certainty. In the third study, task difficulty was manipulated to produce different error rates without altering certainty. Studies 1 and 2 indicated that error and correct responses are processed more similarly when uncertainty is present. Furthermore, uncertainty attenuated the ERN and enhanced the correct-response negativity (CRN), consistent with the error-detection hypothesis. Study 3 indicated that task difficulty alone does not influence the ERN or likelihood of a CRN: Thus, the results are consistent with the error-detection hypothesis for the ERN and establish the role of uncertainty in predicting the CRN, as postulated by Scheffers and Coles (2000).; In chapter 3, the relevance of the ERN to adaptive behaviour and the ability to control responses is considered. The ERN is examined in relation to two behavioural indices of response control: response time (RT) differences between incorrect and correct trials (an index of impulsive response style) and percentage of errors.; In chapter 4, the ERN is examined in relation to motivational incentives and personality traits. Eighteen university students completed a four-choice letter task during four motivational conditions. Monetary incentives for finger and hand accuracy were altered across conditions to either be equal to, or to favour one type of accuracy over the other in a 3:1 ratio. These results emphasize the affective/emotional aspects of the ERN, but suggest that the ability to selectively invest in error monitoring is moderated by underlying personality dispositions. Taken together, the findings offer support for the error-detection account of the ERN. They also reveal a close association between those centres involved in remedial aspects of error monitoring and the emotional/evaluative functions postulated for the anterior cingulate cortex (ACC). (Abstract shortened by UMI.)...