What is the purpose of electroencephalography (EEG)?

The purpose of electroencephalography (EEG) is to detect electrical activity in the brain. This diagnostic technique involves placing small electrodes on the scalp to measure the electrical impulses produced by brain cells as they communicate with each other. EEG is primarily used to diagnose conditions such as epilepsy, sleep disorders, and other neurological conditions by visualizing the brain's electrical patterns.

In contrast, the other options focus on different bodily functions. Measuring heart rhythm pertains to cardiology and would typically involve an electrocardiogram (ECG), which tracks heart electrical activity. Recording muscle activity is done through electromyography (EMG), which assesses muscle response through electrical stimulation. Analyzing blood viscosity relates to hematology and is more focused on the thickness and stickiness of blood rather than any electrical activity. Each of these options concerns different physiological systems, underscoring why the focus on brain electrical activity is uniquely attributed to EEG.