One fundamental question related to low-voltage P3 in HR offspring concerns the potential effect of alcohol in subjects with low P3 at baseline, the subjects who are presumably at risk. Ehlers et al. (1998a) noted that low P3 during a placebo condition was predictive of low level of change or an actual increase in P3 amplitude after alcohol challenge. However, the influence of variables such as ethnicity (Ehlers et al., 1998a) and gender has not been thoroughly explored. Taken together, these findings suggest that, while some electrophysiological differences between HR and LR individuals are apparent without an alcohol challenge, others are seen only in response to ethanol challenges, possibly representing sensitization and tolerance in the HR subjects that may be innate.
