EEG error-related potentials elicited by user-initiated errors at different levels of game difficulty

Error-related potentials (ErrPs) are electrical signals of brain activity elicited by the perception of errors. They have been studied to understand the error processing function of humans and decoded to be used to detect erroneous output in brain-computer interface (BCI) systems. This study investigated the influence of task difficulty on ErrPs elicited by user-initiated outcome errors in an interactive game. The time-domain analysis showed the result that the highest peak of hard-level ErrPs had a longer latency than that of easy-level ErrPs. The time-frequency analysis showed that the power of α (8–13Hz) bands increases at about 200–600ms and the power of 1–5Hz increases starting at about 50ms for easy-level ErrPs, while the power of β (14–30Hz) bands increases at about 100–1000ms and the power of 1–5Hz increases start at about 300ms for hard-level ErrPs. The results provided preliminary evidence that the error processing takes more time for a task with higher difficulty levels, and the difference in spectral power distribution implies the differences in cognitive processes. The study helped explore the modulation mechanism of ErrPs and provided reference factors for the selection of ErrPs decoding algorithm in BCI systems to improve its efficiency and user experience.