FCz, FC2, FC4, FT8, T7, C5, C3, C1, Cz, C2, C4, C6, T8, TP7, CP3, CP1, CPz, CP2, CP4, TP8, P7, P5, P3, P1, Pz, P2, P4, P6, P8, PO5, PO3, POz, PO4, PO6, O1, Oz, O2. Ocular activity was monitored using electrodes positioned on the outer canthus of each eye (Horizontal EOG) as well as above and below the left eye (Vertical EOG). Impedances were kept below 10 kΩ. All EEG signals were referenced to CPz and digitized on-line at 1000 Hz. The signals were then epoched off-line from 1000 ms before to 2000 ms after feedback onset, and re-referenced to averaged mastoid activity. Trial-level EEG data were corrected for ocular and movement artifacts using an algorithm developed by Semlitsch, Anderer, Schuster, & Presslich, (1986), as implemented in the Neuroscan Edit software, version 4.3. As a final step, the processed data were downsampled off-line to 128 Hz using the Matlab (Mathworks, Inc.) resample function to handle anti-aliasing filtering before downsampling.
