dreams dont mean anything!! they are but a reflection of whatever has been on your mind lately (or is an always-present factor in your cognition). dreams are a product of your imagination..
5 stages of sleep
stage 1= transition stage (brain activity slows down a bit)
stage 2= first stage of deep sleep (brain activity gets very low but has spikes in activity every so often)
stage 3 and 4= deep sleep. stage 4 slightly less brain activity then stage 3. both have very low activity, no spikes occur. (this is where sleep walking occurs when it does)
stage 5= REM(rapid eye movement) sleep. characterized by a very high level of brain activity, similar to what would be going on inside the brain if the person were awake and engaged in something.
when we say "brain activity" me mean neural activity, or even more simply: how many neurons are firing (releasing neurotransmitters) at any given moment. the brain activity that occurs during REM sleep originates from the brain stem, and is considered by most experts to be completely random in nature. however, every time a nueron fires, its "telling" you brain something. usually nuerons are firing in response to sensory stimuli. so while you are sleeping and not thinking of anything or doing anything, all the sudden all this random nueral activity starts going on, nuerons firing all over the place telling your mind that your experiencing a bunch of various sensory stimuli and possibly re activating old memories too. you "awake"into a dream during REM and try to make sense of all this stuff your brain iis telling you that you are experiencing.
(on a rellatyed note... we do not experiencing all 5 stages f sleep just once per night. here is what a night of sleeping looks like:
stage 1, stage 2, stage 3, stage 4, stage 5, stage4, stage3, stage2, stage3, stage4, stage5, stage4, stage3, stage 2, stage3, stage 4, stage5, stage 4, stage 3, stage 2, stage 3, stage 4, stage5, stage 4, stage 3, stage2, stage 1 awake
see the pattern?)
