Research strongly suggests that the negative thoughts and ruminations brought on by anxiety, i.e. worry, occupy working memory (WM) resources that would otherwise be applied to cognitive performance. Although worry decreased cognitive performance for individuals overall, the effects seem to particularly target those higher in trait levels of WM, as they rely on their expanded WM for more advanced problem solving strategies. Furthermore, heightened amplitudes of ACC-generated error monitoring known as error-related negativity (ERN) have been repeatedly shown to relate to higher cognitive performance. A recent hypothesis argues that as worry depletes cognitive resources, this ERN signaling represents a compensatory response in order to prevent cognitive deficits. Across three experiments, we replicate and expand these findings, while further being the first group to analyze cognitive performance in terms of WM, attentional control, anxiety and ERN within one study. In Experiment 1, we showed that the executive function of attentional control prevented worry-induced cognitive deficits in those higher in WM when levels of attentional control were high. In Experiment 2, we supported the claim that the ERN is a response to worry’s depletion of cognitive resources by showing that the relationship of worry and ERN is altered by levels of both WM and attentional control. In Experiment 3, we married these two findings by predicting real-world cognitive performance in the future (GPA) using worry, WM, attentional control and ERN as predictors. Although we replicated Experiment 1 by predicting GPA, ERN failed to interact with worry to account for GPA scores. However, we did replicate findings that ERN generally relates to GPA scores, and that this relationship was altered by individuals’ levels of WM and attentional control. These findings strengthen support for attentional control theory, and produce a number of questions regarding the relationship of ERN to cognitive performance.