There are a number of studies showing the changes in resting EEG and ERPs due to the direct effects of alcohol ingestion [160-162]. However, studies on alcohol-induced alterations in EROs are quite rare. Krause et al. [163] examined the effects of alcohol on event-related desynchronization (ERD) and event-related synchronization (ERS) during an auditory memory task. It was found that the administration of alcohol decreased the early-appearing ERS responses during auditory encoding and increased the later-appearing ERD responses during retrieval; these effects were significant in the slow theta (4-6 Hz), fast theta (6-8 Hz), and slow alpha (8-10 Hz) frequency bands. The authors concluded that alcohol intake has a direct effect on the brain and cognitive functioning by disorganizing the brain oscillatory systems in the theta and lower alpha frequency range during stimulus/task processing. In another study during a selective attention task, Jaaskelainen et al. [164] investigated the dose-related impact of alcohol on auditory transient evoked 40-Hz responses and found that evoked 40-Hz response amplitude was suppressed by alcohol during both attended and non-attended conditions, starting at the blood alcohol concentration
