See Also: NRC Membership Listing > Electroencephalography (EEG)

... An imaging method that detects and records brain waves.

Electroencephalography (EEG) measures the waves of electrical activity produced by the brain by recording electrical output on the surface of the scalp. As many as 128 small electrodes are attached to the scalp. The electrical activity of the brain (brain waves) is detected by the electrodes and sent on to the electroencephalography machine, which records the activity in a computer and then on a paper printout. Brain waves are a reflection of central functions of the brain, as well as states of consciousness. EEG is used to diagnose a wide range of central nervous system disorders, including epilepsy, multiple sclerosis, stroke and sleep disorders. In research, the EEG can provide clues about how the brain processes information by comparing brain wave patterns with human activity, such as learning, remembering, talking, etc…

EEG has long been applauded for the accuracy of its electrical brain signals. Today, even greater resolution has been obtained through event-related potentials (ERPs), tiny electrical brain signals produced by the presentation of diverse stimuli. ERPs are fine-tuning scientists’ understanding of the brain. Two recent developments in EEG technology are further enhancing what researchers know about the brain. First, simultaneous “whole brain” activities can be measured concurrently using a new technology called simultaneous digital EEG acquisition. Second, advances in physics and computer technology have led to the new field of “multimodal imaging,” which combines the EEG with other imaging techniques in locating the origin of electrical and magnetic activity inside the brain. EEG can now be combined with MEG, MRI, or PET to produce better computer models of how the brain responds to behavior.