Past work on the feedback negativity has localized the FRN to the medial frontal region along the midline at site Fz (10-10 system). We relied on the average signal of seven electrodes over the midline in this region, specifically electrode numbers 11 (Fz), 16, 19, 12, 5, 4, and 6 (see Figure 1). For ERP analysis, the FRN amplitude was defined as the mean ± 25 msec around the negative peak amplitude between 200 and 350 msec within our electrode cluster. Latency for the negative peak of the FRN was assessed over the same channels and in the same 200–350 msec window.
