One of the biggest pursuits of science. The only problem is just how much more is beyond those sciences who literally cut themselves off at the legs many times. I realize there are all kinds of different approaches. I think the Buddhists believe in like 6 levels of conscious ranging into the void of nothing-nothing ... but I'll be concentrating on consciousness vs. dream time here from a standpoint of: to the best of my own understanding.

Consciousness expanded: The Human Antennae
There is much more to our waking life that our consciousness absorbs wether conscious or subconscious, kind of like if one were the antennae of a radio picking up every station, sensitive to every vibration whether it was brought into awareness/consciousness or not. This can range from the surface of waking life to deeper tones, vibrations and energies we don't or can't normally pick up with our five senses. In a healthy state we are able to filter through all the stations, receiving what we want or what is needed, leaving the rest to back drop as so much noise. In some cases our dreams are like this as well, continuing its big job of filtering and trying to determine what is important or significant to bring forward while the rest is supposed to wash away.

An example I like is how the Dream Catcher works. A Dream Catcher is a plains Native American tech. They were made to place around an infant so that when they slept the good dreams would filter through and bad dreams would be caught in the web to burn away in the sun when placed outside to face the dawn.

Consciousness: The Waters
Consciousness is the awareness of our waking life, the prossess of thought, self and surroundings to which we are aware of with our five senses and the expanded as described above being absorbed and processed.

The conscious in dreams is mostly symbolized as water such as a lake, stream or more specifically the ocean. Water for the conscious has as many variable meanings as there are names for snow among the Eskimo. As with all things in a dream even the activity/flow, texture and color of the water bears meaning. To begin let's say there's at least three levels of dreaming and consciousness as one wades in.

Conscious: The Shallow Water
Even though these dreams are the fore-most dreams at the surface of consciousness, dealing with the daily waking grind, it doesn't mean they are irrelevant or can't be used to help one with problem solving or becoming more aware of things such as dangers, like being drained of energy or having too much stress in a certain area and who or where these are coming from.

What our consciousness attempts to filter usually ends up in the very first dreams upon going to sleep at night, in the beginnings of REM, thus they are the most up front in the shallow waters. They include the most intensifying significance of the daily activities such as stress. Most often these shallow waters are represented in dreams as mental activity, emotional intensity and physical awareness extended into the expanded input that was gathered through the day. Basically these dreams will entail the most potent and fore-most thoughts, activities, input and emotions.

Their symbolism can include but are not limited to:
Insects, small animals such as squirrels, lizards or creatures in shallow waters like shrimp. Other representations can include machines and easily relevant activities related to the last week/month of ritual daily occurrences. People in these dreams will be the ones fore most significant in your life and/or emotional being.

Twilight Conscious: The Mid Waters
In dreams this is a general point between the shallow waters and deeper ocean where both are represented in the dream on various levels. There is potential in this stage to end up more aware of the astral/spiritual realm and deeper, potent emotions and desires. Getting at this stage having these potent emotions/desires can be more of a hindrance getting in the way than useful and should be worked with before trying anything else.

Ideally this twilight of dream time is where one can be more aware of guides, totems and other more spiritual or in depth representations. Mixed with things of the shallow waters will be representations of deeper inputs from "the consciousness expanded", some of which can be in terms of guidance while some of it can still be determined as some antennae racket via things like clairvoyance/audience, empathic sense, deeper tones, vibrations and energies beyond the 5 senses.

There is potential here to be more aware of the astral/spiritual realms. I blame this stage for such troubles as paralysis in dreaming one is awake but can't move. The body is asleep but the mind isn't. I don't mean lucid dreaming but how through dreams and sleep certain layers of reality and awareness can be shed. Some things can occur in this particular awake but asleep thing such as neusance noises, wandering through the house more as like an accidental astral travel and having 'visitors'. I'm sure there is more that can be done at such a point to be able to harness something like astral travel but I don't care to do something like that myself. This particular sort of dreaming in the mid waters usually occurs within the first hour of sleep and most of it can be more due to intense mental stress if it is more of a problematic sort of dreaming and sleep. Again this would fall into potent emotions/desires as something that needs to be adressed first, before any other type of dream work.

Some mid waters symbolisims can include but are not limited to:
People not familiar with in waking life, animals with twilight meanings, physical representations like sand and dunes. Feathers, stones, deeper forms for numbers such as weaving for 8.

Subconsious: The Deeper Waters
Subconsious is also regarded to some as the super-consious. These deeper waters are best represented as the ocean. Here it ranges towards the closer connections to Higher Spirit or the Divine. The Divine being termed here as meaning super-consious, Higher Spirit, higher spiritual form of self and Higher Power or ones God aspect. The Endless Source.

I think the best example I have heard, or one of them, is like the baby in a mothers woumb. In the subconsious state - the time of sleep after R.E.M, when there are no dreams for the longest period of a normal eight hour sleep, it is like being that embrio, connected to the Divine or endless source by this umbillical cord of asleep state. One is also making some use of this connection when they are being creative such as writing or crafting, meditating or in some form of commune like ceremony or prayer. Distraction can have causes like temple headaches, irritability and dislocation.

The dreams bearing these deeper things and meanings will be the ones upon begginig the prossess of waking up after this dreamless stage.

The best dreams to take count of, if you can remember them, are the first ones on waking up, the last ones, if you dream allot, will be going back to mid and shallow waters. Basicly though any dream you can remember to account in a dream journal will still have something to say and bear meanings.

Some deeper waters symbolisims are mostly given to the self interpretation. These are things that you recognize, energies taking shapes only you really understand on a deeper level. Some easier recognitions are dream guides, special or certain animal totems, items, symbols, sacred sounds, places, elements, rituals and some of the earth movements.