In summary, alcohol challenge studies in HR and LR subjects uncover a reactive alpha system. A tendency of slowing of peak frequency within reactive bands and reduced nonlinearity of EEG postethanol is suggestive of a widespread synchronization of neuronal substrates, especially since low frequencies are proposed to be involved in long-range synchronizations in the brain (von Stein and Sarnthein, 2000). Both slow (theta and slow alpha) and fast (beta) frequencies appear to be affected postethanol and this is indicative of a modulation in thalamocortical networks. In their model, Llinas and colleagues (1999) have proposed that the enhanced low-frequency (theta) oscillations in the thalamocortical module can affect the lateral inhibitory drive in the cortex and eventually result in high-frequency coherent activation of cortical modules. Stenberg et al. (1994) also observed that a possible harmonic relationship may exist between the theta and beta bands affected in their study and speculated the presence of related or even same oscillators underlying the ethanol effect on EEG. Hence, these findings provide a strong lead for examining the neurophysiologic and neurochemical bases of vulnerability to acute alcohol.
