Last year I was studying neural networks (an ai concept) and I think it has lead me to a plausible theory of why our body needs to dream.
It starts off with the fact that when you’re born, you have absolutly no programming at all. What I mean by this is you have no knowledge and you react purely on a few basic instincts. If your hungry you cry, if you need to pee you pee.
The way that our brain works can be simulated on a computer. There are a number of input ‘neurons’ which read in data. In your body these would be touch sensitive neurons on your skin, neurons linked to your eyes ect.
At the other end of the net there are output neurons. These would be motor neurons that allow you to move, talk ect. In between are loads of random neurons that have a value (in real life it would be their conductiviy). When input neurons are fired, the signal goes through the net to the out put neurons. Then it is decided wether the out put is useful and if it is, the net is altered to promote this kind of behaviour.
In short, you put in an input, see what the output is, if you like it, you adjust your brain to act more like this. If the output is bad, it is ignored.
The problem with this kind of system is that you have to run data through the net a lot of times to make substantial difference, and you need to experience a variety of situations. This is where dreaming comes in. In the human body you cant just loop through a load of varied data. When you dream, I beleive that your mind produces a wide variety of situations to run through your net. In your dreams you may see monsters and all sorts of other things that you either haven’t experienced, or don’t experience very often. This allows your ‘neural net’ to adjust itself to situations that would not normally arise.
This behaviour is very important. Take ancient man. He may never have seen a tiger or fierce animal before. When he see’s one he wouldn’t know to kill it or run away. The thing is, he’s probably dreamt about fierce creatures, and his mind has developed a sense of fear.
If we didn’t dream, I don’t beleive our bodies would really have the ability to respond inteligently to situations we haven’t been in before.
I would appreciate any comments on this theory, even if you disagree. If bits of it don’t make sense I’ll exlain them properly if you ask.