Early correlates of error-related brain activity predict subjective timing of error awareness.

Humans are remarkably reliable in detecting errors in their behavior. Whereas error awareness has been assumed to emerge not until 200-400 ms after an error, the so-called early error sensations refer to the subjective feeling of having detected an error even before the erroneous response was executed. Here, we collected electroencephalogram (EEG) to track how early error sensations are reflected in neural correlates of performance monitoring. Participants first had to perform a task, and then had to indicate whether an error has occurred and whether this error was detected before or after response execution. EEG results showed that early error sensations were associated with an earlier peak of the error-related negativity (Ne/ERN), a component of error-related brain activity that occurs briefly after the error response. This demonstrates that early error-related activity influences metacognitive judgments on the time course of error awareness, and thus contributes to error awareness.