variations in externalizing proneness. These studies have demonstrated inverse relationships between levels of externalizing tendencies and amplitude of two brain event-related potential (ERP) components: the error-related negativity, or ERN (a negative polarity response that occurs following performance errors on speeded behavioral tasks; Hall, Bernat, & Patrick, 2007), and the P300 (a positive polarity response that occurs to task-relevant stimuli; Patrick et al., 2006).
