Electroencephalogram (EEG)

An electroencephalogram (EEG) is a recording of the electrical waves of activity that occur in the brain, and across its surface. Electrodes are placed on different areas of a person's scalp, filled with a conductive gel, and then plugged into a recording device. The brain waves are then attracted by the electrodes, travel to the recording device and then amplified so that they can be more easily seen and examined. The EEG recording can be used to examine a variety of brain functions including sleep (the different stages of sleep) and different psychological disorders.