In the current study, total ERO theta power (which is a combination of both phase-locked and non-phase-locked activity) was computed from the outcome trials of loss and gain conditions. Since theta activity has been shown to underlie both N2 and P3 components of the ERP [14,69,95], theta power (3.5–7.5 Hz) within the TFR corresponding to 200–500 ms of post-stimulus time window (corresponding to N2 and P3 components of outcome-related ERPs) was processed (see, Kamarajan et al. [14] for detail). The filter setting to extract theta band included a 5th order Chebyshev type I filter (two-step cascade type) with ripple factor (ε) of 0.108 and ripple attenuation (Rp) of 0.05. Only the subjects who had at least fifteen artifact-free trials for each condition were included for further analyses.
