Wired for Sleep Using electrodes pasted to the scalp, the electroencephalogram (EEG) detects changes in the brain’s electrical activity. Other instruments record eye and muscle movements, respirations, heart rate, and airflow. Although it may look uncomfortable, most people involved in sleep studies become oblivious to the electrodes and wires as they drift into sleep (Carskadon & Rechtschaffen, 2005).

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