We also found some significant associations between changes in standard-tone P2 and adolescent alcohol use, as measured with RAPI, and with MAX-D24. Auditory P2 component was proposed by Crowley and Colrain (2004) as mainly reflecting stimulus feature evaluation, and P2 amplitude appears to be under partial genetic control (Katsanis et al., 2007). Our results suggest that both alcohol use and genetic factors could independently modulate P2. Alcohol use was associated with P2 changes and that relationship seems to be modified by genetic similarity. P2 amplitude correlated negatively with self-reported alcohol use, consistent with previous studies suggesting P2 reductions after acute ethanol use (Jääskeläinen et al., 1996) and in chronic alcoholics (Romani and Cosi, 1989).
