there was a study done last year on insomniacs...here is the basic layout:

The experimental group is the insomniacs (actually, it was people that do not dream, but I don't know the term for them, so from now on I'll call them insomniacs), the control is "normal" sleepers.

They have people play tetris a certain number of hours a day. Take some time off (for the control, to sleep). And then come back. The control group dreamed about tetris (you know you've done it before), and consistently got better at the game. The insomniacs did not dream of tetris and DID NOT IMPROVE AT ALL, NO MATTER HOW MUCH THEY PLAYED.

So the researchers conclude that on some level, dreams must be where your brain actually takes the day's activities and blazes the pathways for your memory.

The site I saw it on is currently down...but as soon as it is up again, I'll post the link.

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