Figure 5

Error-Related Potentials. Grand-average of the event-related potentials for error and non-error conditions in the ErrP Calibration Speller (left side) and in the Center Speller (right side) experiment. The top rows show the voltage trace at electrode Cz (thick lines) and PO7 (thin lines) for the error (red) and non-error (green) conditions. The average voltages of five intervals (depicted by the gray patches), are shown as scalp topographies in the two rows below. The third row shows the scalp topographies of the sgn r² values, averaged in these intervals. The bottom plot shows the time evolution of the sgn r² values for electrode Cz and PO7. In the scalp maps, electrodes Cz and PO7 are marked with thick crosses.