What is Electroencephalography (EEG)?

What is Electroencephalography (EEG)?

Authors: Skyler Hughes, Madeleine Kirby

Undergraduate interns for the B-RAD Lab at UA

An ​Electroencephalogram, or EEG, is a method of detecting and measuring electrical impulses in the brain through the use of electrodes placed on the scalp. These electrodes are small, metal disks that are strategically arranged on a cap that are attached by wires to a computer, which displays the electrical waves on a graph in real time. The electrodes detect small electrical signals and measure voltage changes resulting from the movement of ions between neurons, which are nerve cells found in the brain. These EEG signals, which can be recorded during rest, in response to external stimuli or during mentally stimulating activities, can be analyzed to study cognitive processes and behavior. EEGs can also be used to monitor abnormal brain activity, study brain activity during sleep or coma, or assess brian damage from injury. The results of an EEG are recorded as waves, which display the differing frequencies (waves per second) depending on alertness, arousal, etc.