What is the primary purpose of an EEG (Electroencephalogram)?

The primary purpose of an EEG, or electroencephalogram, is to measure the electrical activity in the brain. This is accomplished by placing electrodes on the scalp that detect and record brain waves, providing insights into various neurological conditions. An EEG can help diagnose and monitor disorders such as epilepsy, sleep disorders, and brain injuries, as it reflects the brain's activity patterns.

In contrast to options regarding blood flow measurement, brain structure imaging, or heart activity, these do not pertain to the core function of an EEG. Blood flow measurement indicates vascular health and typically involves techniques such as fMRI or PET scans. Assessing brain structure often requires imaging methods like CT or MRI, which visualize physical brain structures rather than electrical activity. Monitoring heart activity is relevant in specific sleep studies or cardiology exams, not in the context of EEG. Thus, measuring electrical activity in the brain is distinctly the role of an EEG.