What does EEG stand for in the context of sleep studies?

EEG stands for Electroencephalography, which is a technique used to record electrical activity in the brain. In the context of sleep studies, EEG plays a crucial role in identifying and classifying different sleep stages, such as REM (Rapid Eye Movement) and non-REM sleep. The electrical signals captured by EEG provide insights into brain activity patterns that reflect sleep depth, sleep disorders, and overall brain function during sleep. This information is essential for diagnosing conditions such as insomnia, sleep apnea, and other sleep-related issues, making EEG a fundamental tool in sleep medicine.

In contrast, the other terms represent different types of tests: electrocardiography monitors heart activity, electromyography measures muscle activity, and electrothermography relates to measuring temperature variations. Each of these has its own application and relevance, but none are focused on brain activity in the context of sleep, thereby confirming why Electroencephalography is the correct answer for this question.