Hz, and were resampled at 256 Hz for the sake of uniformity in signal analysis. The continuous EEG was segmented into epochs of 100 ms pre-stimulus (for baseline correction) plus 800 ms post-stimulus of the outcome stimuli. Digital low-pass filtering was performed at 32 Hz for ‘peak-picking’ and at 16 Hz for the display of waveforms. All segments exceeding ±75 μV threshold were rejected as artifacts. The percentage of trials exceeded the threshold of 75 μV ranged from 4% to 12% with the average of approximately 5%. Only those ERP data that had a minimum of 15 trials in each of the conditions (−50, −10, +50, +10) were selected for the analyses. The grand averaged ERPs of each individual were further screened visually for further artifact rejection. The averaged waveforms of two male subjects were excluded from the study based on the peak activity at FP1 and FP2. The trials with EOG activity were removed rather than corrected using the EOG reduction algorithms for two reasons: 1) these algorithms sometimes introduce artifactual data, principally because the eye recording does not accurately represent the actual EOG effect on the EEG, and 2) there were very few trials that had EOG contamination.
