why do people have dreams when they sleep?

Answer 1

A dream is the experience of envisioned images, voices, or other sensations during sleep. Dreams often portray events which are impossible or unlikely in physical reality, and are usually outside the control of the dreamer.

The scientific discipline of dream research is oneirology.

Most scientists believe that almost all humans dream with approximately the same frequency. Even those who rarely recall dreams report having them if awakened during rapid eye movement (REM) sleep.

There is no universally agreed-upon biological definition of dreaming. It is unknown where in the brain dreams originate — if there is such a single location — or why dreams occur at all. However, there are many competing theories of the neurology of dreams.

Jie Zhang proposes that dreaming is a result of brain activation and synthesis, and at the same time, dreaming and REM sleep are controlled by different brain mechanisms. Zhang hypothesizes that the function of sleep is to process, encode and transfer the data from the temporary memory to the long-term memory. Zhang assumes that during REM sleep, the non-conscious part of brain is busy to process the procedural memory; in the meanwhile, the level of activation in the conscious part of brain will descend to a very low level as the inputs from the sensory are basically disconnected. This will trigger the continual-activation mechanism to generate a data stream from the memory stores to flow through the conscious part of brain. Zhang suggests that this pulse-like brain activation is the inducer of each dream. He proposes that, with the involvement of brain associative thinking system, dreaming is, thereafter, self maintained with dreamer's own thinking until the next pulse of memory insertion. This explains why dreams have both characteristics of continuity and sudden scene changes.

"Dream incorporation" is a phenomenon whereby an external stimulus, usually an auditory one, becomes a part of a dream, eventually then awakening the dreamer. The term "dream incorporation" is also used in research examining the degree to which preceding daytime events become elements of dreams. Recent studies suggest that events in the day immediately preceding, and those about a week before, have the most influence.



Great Newsweek article
"What Dreams Are Made Of":
http://msnbc.msn.com/id/5569228/site/newsweek/

Answer 2

There are many theories. But here's some of what I think. They are random firings within the brain. When our body sleeps, our brain still nees a level of activity to keep our bodies alive, so it is still active and looking for stimulation, and it searches through your memory to satisfy that need, in turn creating the sense of an alternate reality where the past things that have happend to you or things you thought of mesh together into an insignificant event. But I think there is more to it than that.

Answer 3

Dreaming is a way for the brain to "de-bug" to sort out the past day's events....

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Answer 4

Inner desires or fears comming out from the subconious mind.

Answer 5

the brain is still working, although we are in a pre-paralized state