Response accuracy rating modulates ERN and Pe amplitudes

Response accuracy ratings are often used in studies investigating the relationship between ERP correlates of performance monitoring and error awareness. Still, it is unclear whether the act of rating response correctness changes ERP correlates of performance monitoring. In order to investigate the influence of response accuracy ratings, a flanker task was conducted with or without concomitant accuracy rating and ERPs were compared between the two conditions. Error- and correct-related negativities were increased in the rating condition, possibly indicating an increase in performance monitoring. The error positivity differed more strongly between errors and correct responses in the rating condition. Additionally, correct reaction times were slower and post-error slowing was diminished in the rating condition, pointing toward a more cautious response strategy. These possible confounds should be taken into account by future studies using response accuracy ratings.