Delta waves, in which your brain is electrically pulsing slowly at about one wave per second, are typically only seen in deep sleep. Then there’s theta-wave sleep. At about five cycles per second, this mental state occurs when you’re dreaming. The two waking states are alpha and beta. The alpha state is relaxed, aware, and attentive, such as when you close your eyes and meditate. Beta, meanwhile, is the stimulated, hustle-and-bustle state in which most of us live our lives.
