Error-related negativity and error awareness in a Go/No-go task

Error monitoring is crucial for the conscious error perception, however, the role of early error monitoring in error awareness remains unclear. Here, we investigated the relation between the ERN and error-related theta oscillations and the emergence of error awareness by conducting time- and phase-locked averaging analysis based on 4–8 Hz filtered data and phase-locked time frequency analysis. Results showed that while the ERN did not differ significantly between aware and unaware errors, theta power was stronger for aware errors than for unaware errors. Further, when continuous EEG was filtered outside the theta band, the ERN results confirmed this pattern. Additionally, when the non-phase-locked component was removed from continuous EEG, stronger theta power was still observed in aware errors compared to unaware errors. Collectively, these findings may suggest that (1) the ERN emerges from phase-locked component of theta band EEG activities; (2) the ERN engages in conscious error perception and serves the emerging error awareness through the activity of theta oscillations. Thus, early error monitoring is a precursor to error awareness, but this relationship is masked by high-frequency activity in aware errors when the ERN is not filtered outside the theta band in the Go/No-go task.