Which tool is used to create a graphic representation of electrical activity in the brain?

The tool used to create a graphic representation of electrical activity in the brain is an electroencephalogram (EEG). An EEG measures and records the electrical activity of the brain through electrodes placed on the scalp. This technique captures brain wave patterns and can be crucial in diagnosing conditions such as epilepsy, sleep disorders, and other neurological issues.

In contrast, an electrocardiogram (ECG) records the electrical activity of the heart, making it unrelated to brain function. An echocardiogram is an ultrasound imaging test that evaluates heart conditions by creating pictures of the heart's structure and function. A fetal monitor is designed to track the heart rate and well-being of a fetus during pregnancy and labor, which also does not pertain to brain activity. Each of these other tools serves a specific purpose, distinct from the role of an EEG in monitoring brain electrical activity.