It is well established that alcoholics manifest reduced amplitudes of P3b to task-relevant target stimuli, particularly over parietal regions; similarly, alcoholics manifest low frontally distributed P3a to rare non-target stimuli in both visual and auditory modalities (for reviews, see Porjesz and Begleiter, 1996; Porjesz et al., 2005). Koskinen et al. (2011) analyzed auditory P3 in a twin study, and lower P3 to novel stimuli (P3a) was consistently associated with alcohol use in adolescence. More recent studies have indicated that low P3b amplitudes are present not only in male alcoholics, but in female alcoholics as well, though not to the same extent as in males (Hill and Steinhauer, 1993; Prabhu et al., 2001; Suresh et al., 2003). The lower P3 amplitude is also significantly associated with increased impulsivity and decreased activity of frontal sources in alcoholics (Chen et al., 2007). However, in an unusual sample of treatment-naive actively drinking adolescents with alcohol dependence, no reduction of P3b amplitude was observed in comparison to matched controls (Cuzen et al., 2013), possibly due to absence of any family history, comorbidity, and short drinking history.
