Although P3 differences between the risk groups were significant at central and parietal regions for the loss condition in older males and at occipital region in younger females, the source analysis using surface Laplacian (CSD maps) revealed weaker current density in HR offspring at the frontal sources. These frontal deficits or ‘hypofrontality’ of HR subjects as demonstrated in CSD maps may explain the lower P3 in these individuals (as discussed in detail in the following sections). Further, imaging studies in adolescent subjects who were vulnerable for and/or diagnosed with substance use disorders (SUDs) (Bava et al., 2009; Bava et al., 2010; Bava and Tapert, 2010; Casey and Jones, 2010; Dayan et al., 2010; Feldstein Ewing et al., 2014) and other externalizing disorders (Rubia et al., 1999; Rubia et al., 2000) have shown evidence for frontal lobe dysfunction, possibly due to a “dysmaturational pathogenesis for hypofrontality” as phrased by Rubia et al. (2000) in their work on ADHD children.
