How does an electroencephalogram (EEG) function?

An electroencephalogram (EEG) functions by recording the electrical activity of the brain through electrodes placed on the scalp. This method allows for the detection of voltage fluctuations resulting from the ionic current within the neurons of the brain. By capturing these electrical signals, EEG provides a real-time overview of brain activity, which can be crucial for diagnosing conditions such as epilepsy, sleep disorders, and other neurological issues.

The accuracy of the EEG in reflecting brain activity is essential for clinicians, as it can help identify abnormal patterns indicative of various disorders. The temporal resolution of an EEG is particularly high, making it an effective tool for monitoring brain function over time and during different tasks or states, such as sleep or wakefulness.

Other methods mentioned, such as measuring blood flow or visualizing brain structure, do not capture the electrical activity directly and therefore do not serve the same diagnostic purposes as an EEG. Similarly, assessing brain metabolic activity focuses on biochemical processes rather than the electrical dynamics essential to understanding neuronal behavior.