Error awareness—the ability to detect errors, adjust strategies, and prevent mistakes—is critical in high-stakes human–computer interaction (e.g., aviation, autonomous system supervision), as well as in everyday life. However, this ability deteriorates under heavy cognitive load, and effective countermeasures remain scarce. We investigate whether transcranial direct current stimulation (tDCS) can mitigate this deficit. Using a multi-rule task with EEG, we found that under high load, tDCS over the left dorsolateral prefrontal cortex (DLPFC) significantly improved error awareness, reflected in both behavioral measures and a neural index. Crucially, mediation analysis showed this effect was achieved by improving working memory capacity, facilitating better real-time error detection. Our findings demonstrate that neurostimulation sustains self-monitoring by augmenting depleted cognitive resources. We formalize this in the Dynamic Cognitive Resource Barrel Theory: error awareness is limited by the most depleted cognitive “stave” after primary task demands. These results offer a principled path for designing neuroadaptive systems that predict and support these processes in critical moments.
ACM CHI Conference on Human Factors in Computing Systems