Brainwaves are the electromagnetic waves produced by activity in the brain. The frequency of these waves is measured in cycles per second, or hertz (Hz). Brain-mapping research shows that each of our states of consciousness is associated with a specific pattern of brainwave activity. Brainwaves fall into five classes: Beta (30–13 Hz) is associated with ordinary consciousness and focused awareness; alpha (13–8 Hz) with relaxation and meditative calm; theta (8–3.5 Hz) with creativity, insight, and meditation; gamma (30–85 Hz) with advanced meditation; and delta (3.5–0.5 Hz) with restful sleep.