Dreamwork Fundamentals - The Three States of Consciousness

...the first state is Waking. So when you're awake and walking around doing your regular daily activities your sense organs are collecting information. Say for example your eye is collecting... well, not collecting, but reacting to certain frequencies and intensities of light that manage to get into your eye and hit the rods and cones on your retina. These rods and cones will trigger and fire an electrochemical signal into your brain. Your brain then takes this sensory data, along with all the other data coming in from your other sense organs and compiles it into an experience. That is what we actually are experiencing all around us when we walk around or sit around or whatever we do during the day when we're awake. It's a mental representation of the information that our sense organs are collecting.

Now when we dream, that's another level of consciousness that we experience. It's the same hologram generator that creates the experience that we have but when we're dreaming the data is mostly coming from internal sources like memory, emotional state, that sort of thing. So it's the same function of the brain that generates the experience of a dream as the same function that generates the experience of waking life.

Now what happens when that function is not active... it's when it's not taking data and compiling into a representation which we experience. When that hologram generator is shut off that's what we call Non-dream Sleep and in Tibet they've been studying dream yoga and sleep yogas for quite a long time and they figured out ways of remaining fully conscious within all three states...