Is there an evolutionary explanation for why we dream (When asleep)?

Perhaps it offers a glimpse into our subconscious, therefore allowing us to improve?

One theory is that dreaming gives the brain an opportunity to rehearse responses to threats. They act like virtual war games and increase the likelihood of survival in case of actual threat.

@Harp Cool! Good answer!
And harps are cool too! I play one!

There are evolutionary explanations for why animals enter a “rest state” (i.e. sleep) during night. (Or if they’re active during night, during the day). If you run a game theory simulation, it turns out that alternate active and resting periods, timed with food availability, turns out to be more efficient than just staying active for your whole life.

For conscious animals with complex brains, I think the explanation for dreams is basically the same as the explanation for consciousness itself—it’s an emergent property of brain activity. The brain has limited activity in our “rest state,” and there is little if any sensory input, but we don’t become brain-dead. You could say that our experience of dreams is simply what happens when a brain is starved of sensory input and physical “guidance” and thus its processes turn more inwards.

To quote Shakespeare:

Sleep which knits up the ravelled sleeve of care…

Which is just a poetic way of expressing some of what scientists are more discovering. This is the time when our brain processes and “files” stuff so we can have an uncluttered brain to deal with future events.

I like Willie’s description better.

Read this article from human-nature.com, by professors Franklin and Zyphur:
http://www.epjournal.net/filestore/ep035978.pdf

Yes, it is a hefty and lengthy article…but it is well worth the time if you really want an academically sound answer.

Learning consolidation. Happens at night.

Next time the bear wants to steal our food we’ll be ready. Yay!

My theory is that the brain is still active whilst asleep trying to store the important memories of the day into long term memory whilst filtering out the unneeded information. This sort of brain activity is interpreted by the brain as sensory input which creates the dreams.

Evidence for: Random activation hypothesis, learning theories of dreaming, awake brain surgeries where parts of the temporal lobe are stimulated and a memory is triggered to the patient

Problems: why it is so easy to forget dreams if they are supposed to be useful unless if they are sent straight into the unconscious as to aid processing (ie if the situation happens you don’t need to consciously process it so you find the adequate action and perform it faster).

Another problem I find is why the brain doesn’t encode smell/taste. A possible explanation is that its very hard to remember a smell/taste when the stimulus is not there, however vision and sound is easier to remember (we have an inner eye/ear that we use for cognitive processing but no inner nose/tongue). Touch is a strange concept as I swear in some dreams I can feel stuff, but that could just be the brain filling in the gap in the dreamstate.

Isn’t dreaming a sort of process of defragmentation? at one time you could not defragment your computer while it was is use – are computers still like that? so the brain undergoes this process while we are asleep.

@Harp That was a good answer, but what came to my mind was, “OK, so my brain is rehearsing what to do when I’m flying like a bird and suddenly lose my ability to fly!” LOL!
This is a good question. I wonder…how much your dreams subconsciously influence you during your waking hours.

@Val123 That statement almost made my brain explode. That is an excellent question!

@valleygirl: good one – but our dreams affect our awakeness – just as surely as our subconscious affects our dreams. It’s a circle of mind.

Dogs dream too…..and cats….