Fig. (4) Source analysis .Left side of the figure: statistical differences (the p-value appears in parentheses) of the LORETA solutions of IC and VC targets for the P3a and P3b components in the mesial surface of both hemispheres. Notice that both components present a statistically significant increase of activity in the BA 24 (dACC) in the invalid condition with respect to the valid condition (see Table 2). Right side of the figure: single dipole localization of the difference wave obtained by subtracting the ERPs of the valid condition from the ERPs of the invalid condition. A single dipole is fitted for the time windows of the P3a and P3b. Notice that the P3a dipole fitting was located inside or in the proximities of the dACC cortex. The P3b single dipole was located more posterior. Best: residual variance (RV) obtained in a single time point of the considered time window.