One of the most consistent electrophysiological measures that characterize male alcoholics is the low amplitude of their P3 components; female alcoholics also manifest reduced visual and auditory P3 amplitudes, although to a lesser extent than male alcoholics. Recent findings indicate that not only are P3 components at low amplitude in alcoholics, but the neural oscillations underlying P3 are deficient in alcoholics as well. The findings that both evoked delta and evoked theta oscillations underlying P3 are deficient in alcoholics imply dysfunction in both the cognitive processes and neural correlates that mediate these oscillations. Event-related delta oscillations are related to signal detection (i.e., stimulus discrimination of one object from all other objects) and decisionmaking, whereas theta oscillations are associated with cognitive processes such as attention, alertness, and memory (Basar et al. 1999). Alcoholics are also deficient in the production of evoked gamma oscillations during the processing of target stimuli. As these oscillations are related to selective attention processes and working memory, these findings indicate that alcoholics manifest deficits in cognitive functions associated with these oscillatory processes.
