Dunno about you, but when I sleep during the day, (I’m usually a normal night sleeper and don’t have a weird schedule like EMTs etc.) which I don’t do often, I can never really manage to “sleep.”
This “day sleep” that I encounter–remember that this is not a daily habit but maybe once every two months–is not really a sleep but just one dream “extravaganza.” I have extraordinary dreams, sometimes populated by amazing amounts of people, and sometimes everyone is nice but sometimes everyone is not nice. Sometimes people whom I have not thought of for two decades surface in these dreams.
Why is this day sleep so different from my normal nightly oblivion? It has nothing to do with light coming in the window or noise, since I wear earplugs and the blinds pretty much block out all light.
My wife has also reported this “pseudo-sleep.” Needless to say, I am not a Power Napper.
What is going on in the vast network of dendrites and neurons? What exercise is my brain trying to have?
I’m afraid I don’t have any Internet cites (or sites) but I can pull out a number of books on the subject if you like. That being said, let me attempt to explain.
Basically it isn’t that your daytime dreams are especially powerful. It is that you are an especially vivid dreamer and during your daytime dreaming, you are not sleeping quite as deeply as you generally do during the night, and thus you recall them better. Metaphoricly they are nearer the surface, if you will.
In addition, since you are usually a night sleeper, usually your mind is an “active” mode during the day and that can cause two different things, your senses are still somewhat “on” and can bring in outside stimuli despite attempts on your part to mask them, and the still somewhat-active mind can incorporate them into different aspect of your day-sleep dreaming. It also can cause your brain to me more imaginative than it might be when functioning at night since that is its normal function at that time. It has received the “shutdown” signal, but it is a bit out of the habit at that time of the day.
TV
Actually, dreams occur during REM (rapid eye movement) sleep, which is a deep stage of sleep. (There are 4 stages, IIRC.) You remember them more than your nightly dreams (and there are ordinarily four different REM stages a night) because you more easily remember the dreams you had just before awakening.