More consciousness...

State(s) of consciousness defined as the overall pattern of activation.

The OVERALL pattern of mind-brain activation; includes, but is more than simply being conscious or unconscious or "the subconscious" mind. These states are fluctuating, however, any pattern of activation is likely to recur; and a recurring pattern of activation may become a persisting TRAIT rather than simply a state. The state reflects both the type of processing going on (or degrees of various processes) AND the content being processed. Many things can affect the overall pattern of activation; keep in mind you have some control over this. SO, be mindful over whatever pattern of activation you allow - because it will recur or possibly even persist and may not go away (or at least not easily).

A simple neural network:
With all of this talk about patterns of neural activation, here is a simple schematic diagram. Imagine TWO stimuli, create TWO waves of activation - maklign ONE unique pattern of activation. Linking those two pattern may be the basis of memory.

Also, it might help to read up on EEG. Lord help me, I'm sending you to Wikipedia! Mostly for the pictures and basic method of EEG.
Common types of brain waves (see Carter, p. 179):
Alpha: low amplitude, moderate/high frequency, eyes open, THINKING
Beta: low amplitude, high frequency, ALERT
Theta: moderate amplitude, low/moderate frequency, DROWSY/RELAXED
Delta: high amplitude, slow frequency, DEEP SLEEP, "slow waves"

EEG is also used to collected brain reactions to specific stimuli by "averaging" over a number of trials so random activity cancels itself out. These reactions are also sometimes called brain waves, but are known more precisely as:
1) "evoked potentials" for reactions to sensory nature of the stimulus (<200 ms).
2) "event-related potentials" for reactions to the meaning of the stimuls (approx 200+ ms).

SLEEP
Stages
Awake
REM sleep - dreamiong, or paradoxicall sleep
Stages 1,2,3,4