Brain Signals and Alcoholism

Electroencephalogram (EEG) is the recording of electrical activity through various electrode sensors placed on the scalp. The electrical signal is recorded as waves that can be classified as normal or abnormal. Different types of normal waves can indicate various states or activity levels of the functioning of the brain. Abnormal electricity of the brain may represent many brain disorders, which can be detected by analyzing EEG signal pattern. However, it is very difficult to get useful information from these signals directly in the time domain just by observing them. They are basically non-linear and nonstationary in nature. Hence, their important features can be extracted for the diagnosis of different diseases using advanced techniques in engineering. The measurement of the brain signals involves the use of Electroencephalogram (EEG) at rest and Evoked Potentials (EPs). Brain activity of alcoholics and nonalcoholics differs in many ways. These differences prevail in alcoholics along with imbalance in excitation and inhibition processes in their brains. There are two ways in which the activity of the brains of the alcoholics can be revealed, analysing the images of the brain and the electrophysiological mapping of the brain. Magnetic resonance imaging (MRI) and positron emission tomography (PET) are the examples of the techniques that produce the images of the brain structure, where as EEG and EPs are included in the other method of measurement. This paper summarizes the techniques of mapping of brain signals, which can best reveal the brain activity of alcoholic subjects as it occurs in time.