What does an EEG primarily measure?

An EEG, or electroencephalogram, primarily measures the electrical activity of the brain. This diagnostic tool is used to detect abnormalities in brain function by recording the electrical impulses that occur in the brain. The electrodes placed on the scalp pick up these electrical signals, which reflect the brain's activity in real time. This information can be invaluable in diagnosing various neurological conditions such as epilepsy, sleep disorders, and other brain-related issues. The focus on brain activity is what distinguishes EEG from other diagnostic tools, as it specifically provides insight into how the brain is functioning at any given moment.