P300 ERP components elicited by target (P300b) and novel nontarget (P300a) stimuli were identified within each averaged epoch. P300 was defined at each electrode as the highest positive peak within a time range of 275–575 ms after stimulus onset. P300 amplitude was measured as the voltage difference between the peak and the average voltage during the prestimulus period. P300 latency was the millisecond difference between stimulus onset and the peak.
