interesting descriptions of dreams:
http://www.astraltraveler.com/dream-states.htmlAnd some definitions of Brain Wave Activity during sleep.
Beta is the first stage of sleep. During this time the brain begins to shift the mind from it waking consciousness to prepare it to enter into the next level of sleep. The body automatically lowers the heart rate, blood pressure, and body temperature and the muscles of the body begin to relax.
Alpha is the condition we enter during the time between the stage of being awake and actually drifting off to sleep. During this state we often feel the sensation of drifting. Most of our dreams happen during this stage of sleep. It is easily recognizable by rapid eye movements (REM) which can last several minutes.
The Theta stage is when the body is fully engulfed in sleep. During this stage brain waves move quickly from theta to delta waves. If we are awakened during this state, we often become disoriented because it takes the body several minutes to snap back into its conscious state.
Delta is the deepest level of sleep. Most people don't dream during this state.
Of course it is training our brain waves that allows us to have an OBE....if we wish.