Neuroscan system (Versions 4.3–4.5; Compumedics USA, Charlotte, NC) at the sampling rate of 500 Hz. The entire EEG data was resampled offline to 256 Hz for the analyses. In this study, only ‘loss 50’ (representing the loss condition) and ‘gain 50’ (representing the gain condition) were analyzed, as majority of the subjects had more trials for the 50¢ than the 10¢ condition. The preprocessed trial epochs with waveforms exceeding ±100 μV (about a third of total trials) were excluded from the analyses.
