The “outcome window” (1500 ms) began with the onset of OS, as the objective of the study was to analyze the outcome-related potentials of the ERPs (see Fig. 2). The ORP amplitude was measured as the voltage difference from the pre-stimulus baseline (200 ms) to the largest positive going peak in the waveforms filtered at 0.25–32.0 Hz in the latency window 275–700 ms after the stimulus onset, whereas the ORN was measured as a baseline-trough in the waveforms filtered at 2.0–16.0 Hz within post-stimulus 200–275 ms (Fig. 1). Since the ORP is very robust and prominent (compared to the ORN) and also involves slow wave activity (less than 2 Hz), the ORN component, which is often small and subtle, gets subsumed by the ORP component and is not apparent in the ERP signal. A filter setting of 2.0 – 16.0 Hz makes the ORN component relatively more prominent than with the regular filter setting of P3/ORP component. This approach of removing the slow wave activity has already been employed by several studies on error-related negativity (ERN) paradigms. For example, Luu
