Abnormalities in EEG and ERP measures have been demonstrated to be good markers for certain neurological and psychiatric impairments as well as good indicators of risk status for certain conditions, including alcoholism. Research has consistently found that when compared with normal control subjects, the P3 component of the ERP is smaller (i.e., has a reduced amplitude) in alcoholics and children of alcoholics who are at increased risk of developing alcoholism but have not yet been exposed to alcohol (see figure 2) (Begleiter et al. 1984; for a review, see Porjesz et al. 2005). The lower P3 amplitudes, coupled with weaker and less well-organized sources (i.e., networks) in the brain, reflect inefficient allocation of resources during neural processing in alcoholics and offspring at risk. Low P3 amplitude also has been described in people with other disinhibitory disorders, such as substance abuse, antisocial personality disorder, conduct disorder, and attention deficit hyperactivity disorder (for a review, see Porjesz et al. 2005).
