Beta frequency rhythms are also known as inhibition-based rhythms. Increased beta power in the EEG of alcoholics, particularly in the resting condition, has been well documented (Propping et al., 1981; Costa and Bauer, 1997; Winterer et al., 1998; Bauer, 2001; Rangaswamy et al., 2002). Increased beta power was observed at all scalp loci in the large Collaborative Study on the Genetics of Alcoholism (COGA) sample, but was most prominent in the central region for slow-medium-frequency beta (12–20 Hz) and over the frontal regions for fast beta (20–28 Hz) (Rangaswamy et al., 2002). Increased beta activity, particularly fast beta (19.5–39.8 Hz), has proved to be an excellent predictor of relapse (Bauer, 2001; Saletu-Zyhlarz et al., 2004). Desynchronized beta activity over frontal areas in relapsers has been suggested as a correlate of functional disturbance of prefrontal cortex (Winterer et al., 1998).
