Our primal structures (that we share with shed loads of other animals) are mostly about homeostasis and survival. These always have to be working otherwise we die (breathing stops, temperature regulation goes loopy etc) but our neocortex (the crinkly bit on the outside), that’s a bit more advanced and it’s where we do lots of our thinking that takes us beyond just being instinctive and primal. Not a lot of animals have this.

So the basic idea is this.

The primal structures can never turn off (or we’d die) but the neocortex can be rested. One of the things the neocortex does is lots of categorization, ordering and sorting of information – e.g. it tells us what we should focus on, what goes with what and what is rubbish and probably not worth focusing on. The cortex is thus constantly and rigidly controlling what we focus on when we are awake. It sorts all the stuff we are exposed to and will discard some stuff as crazy rubbish.

The problem with this is that it’s so efficient it sometimes prevents new or radical thinking because the crazy stuff is sometimes what we need! A perfect example of this is the need for brainstorming exercises to break people away from their normal mode of thinking and be more creative!

So back to “aha!” moments on waking.

When you start to fall asleep the cortical “control” starts to become lifted. But don’t think about it like an on/off switch, think of it like a dimmer switch. Ok, so dreams can be pretty crazy, like that one about the kipper and the bucket of custard on that beach in Hawaii, erm, that’s the dimmer switch all the way off.
But what about the bits in-between on and off? Imagine that dimmer switch turned off more slowly. All that “ja vol mein capitan!” order is removed little by little now and the more random and crazier thoughts and associations aren’t throw away so fast and they aren’t allowed to run riot on that beach in Hawaii either.

This is one way to think about what might be happening just when you’re falling asleep or waking up. Here the cortical control isn’t all-powerful and suppressive, here it’s allowing some stuff through it would normally filter out but it’s also not off (it’s dimmed remember) and just about alert enough to spot and make some sense of that crazy stuff. That’s your aha moment!

So dreams are a brainstorm that’s running out of control. The bits that happen when you’re nodding off and waking up have a bloody good moderator in the room, waiting to pounce on something worth taking further.

http://www.spiegel.de/international/zeitgeist/0,1518,659577,00.html