Indeed, some recent efforts in the search for alcoholism-related endophenotypes have shifted focus away from time-domain P3 amplitude and toward TF measures of ERP activity. P3-related delta and theta power was shown to be reduced in adult alcoholics (Jones et al., 2006) and in high-risk adolescent and adult offspring of alcoholics (Kamarajan et al., 2006; Rangaswamy et al., 2007). Most recently, our group has extended these findings by utilizing a novel, data-driven, principal components analysis based TF analysis method (TF-PCA; E.M. Bernat, Williams, & Gehring, 2005) to reveal a more detailed representation of the multiple overlapping processes related to P3 activity (E. M. Bernat et al., 2007; Gilmore et al., in press). In Gilmore et al. (in press), TF-PCA revealed five time- and frequency-specific event-related delta and theta components, each of which was able to discriminate those subjects with one of six externalizing spectrum disorders from those with no disorder (based on reduced amplitudes in the diagnostic groups) as well as or better than could P3 amplitude. These results demonstrated that TF-PCA derived components may capture more externalizing-related variance in
