Why did we find evidence of adolescent alcohol effects on P3 that have eluded others? We found that both alcohol use and genetic factors play significant roles in P3 generation but only for novel P3. For target P3, the focus of many earlier studies, a significant genetic influence on generation was observed, but in the absence of significant associations or interactions with alcohol use. Might novel P3 be specifically sensitive to alcohol effects? Amplitude of P3 to novel sounds correlated negatively with self-reported alcohol use, as measured with RAPI and MAX-D24. P3 elicited by novel sounds may correspond to a “novelty P3,” sharing resemblance with the P3a subcomponent, elicited specifically by perceptually novel “distracter” stimuli in easy discrimination conditions (such as ours). This “novelty P3,” analogous to the P3 to novel stimuli in our data has a frontal/central maximum amplitude distribution, and it is thought to be associated with redirection of attention monitoring (Polich, 2007; Polich and Criado, 2006). Consistent with previous studies in chronic alcoholics (Hada et al., 2000;Rodriguez Holguin et al., 1999a), subjects with more severe drinking histories
