Nonetheless, the totality of the data from the current study renders it unlikely that a lack of engagement in the task or insufficient statistical power accounted for the absence of the expected association. First, the fact that the difference in theta-FRN amplitude between the gain and loss trials was large and commensurate with that reported in prior work demonstrates that participants as a whole in the current study responded appropriately to losses and were thus engaged in the task. Second, Hall et al. (2007) did find a robust relationship between externalizing proneness and the ERN in a markedly reduced subset of the participants tested in the current study task (i.e., 89 versus 149 participants)—indicating that power to detect a difference in a putatively related brain response should have been adequate in the current study. Consistent with this perspective, we were successful in detecting an association between externalizing proneness and reduced delta-P300 response in the current study, despite the lack of any association for theta-FRN. Finally, when we directly compared findings for ERN and FRN responding in participants from the Hall
