You can't be serious.

The evidence is that if you stay up 3 nights in a row because they do not let you go to sleep you will likely be begging to die or kill them if you can, simply because you no longer care??? lol. I guess who is putting you in that mood but your brain???

Or that if you try to keep notes of a lecture one morning you find out next day you started using a completely new foreign language in your notebook??? Or maybe that you find yourself while driving hitting with your tires the lane separator markers all the time when a proper driver stays in their lane consistently. Those bumps are what wakes you up by the way in the brief moments of sleep while driving lasting a few seconds during which if something happens in the road ahead you are dead or can kill someone. And just imagine what would happen if the bumps didnt wake you up??? (if that happened to you the best you can do is find a rest area and sleep a couple hours immediately, its a life or death choice and all else including arriving late or whatever is less important in the large scheme of things)

So yes i suppose we need more evidence that the brain needs the sleep!!! Because after all who is responsible for the hieroglyphics in my notes or the marker bumps in the tires but my own brain.


Zoltan may be trying to say he thinks the brain itself doesnt need the sleep, its other elements that are putting the brain to sleep that are the core of the problem but to me its seems that the quality of brain's capacities/faculties after days of not sleeping deteriorates dramatically and so many parameters like reaction speed and even the empirical creative flow of ideas are not exactly up trending with time past a certain amount of hours without sleep. So the brain itself is not operating ideally after a while. Either something wants to put brain to sleep that is the brain itself or the cycle and its chemistry that quite possibly has as role to protect that brain (melatonin etc circadian rhythm) and enhance its capacities all over again.
http://en.wikipedia.org/wiki/Circadian_rhythm
http://en.wikipedia.org/wiki/Melatonin


Ps: if you create a simple work output model for humans (work=time integral of power function say, power here meant in a general utility creation rate sense not the physics power) using a power function that deteriorates with time but is refreshed after sleep as function of the duration of that sleep, pretty soon you find out the optimal solution involves a periodic behavior that is work+sleep at some ideal fraction of total time that probably is close to 3:1 for most humans.

But that's for humans as we have evolved to be today. That's similar to, if I asked why we didn't evolve not to need vitamin C, you pointing out that without it we get scurvy, and missing the fact that we may not have needed to evolve to need it. (And in fact most mammals don't; it is probably relevant that afaik all mammals need sleep.)

Sleeping seems to preform a dual purpose in the animal kingdom. Some brain defragging mechanism that no one seems to understand properly. And restricting activity to certain times where the organism functions better.

Not sure who 'we' are. However sea mammals have found a way around the sleep issue. For instance dolphins need to be conscious to breath, so a full sleep would result in death. Hence it has been shown that they sleep with one hemisphere of the brain at a time, while being awake with the other half.

Given that dolphins still sleep albeit in a more restrictive sense, suggests that sleep in some form is a necessary feature of the brain of higher animals.

Secondly the dolphin case suggests the kind of feature, i.e. full sleep equals death, that leads to evolution finding an alternative to the sleep pattern found in most higher animals.

dolphins sleeping;

http://www.youtube.com/watch?v=U7D-f...eature=related

http://www.youtube.com/watch?v=1ZSzI...eature=related

http://www.youtube.com/watch?v=NvzsuMDTe58

Its evident they are not seriously active to very relaxed but somewhat alert too, nothing like their usual playful behavior however.

The real impediment to evolving sleep free humans is that children who do not sleep drive their parents insane.

This reduces the likelihood of them having siblings or reaching a healthy adulthood as they have a greatly enhanced possibility of ending up in full year boarding schools.

So, couples with the genes to produce less sleep dependent humans are disinclined to reproduce again after the first one.

I like this. But you're supposed to make it rhyme, you know.

No, evolution about differential individual reproductive fitness (which is NOT the same things as saying group selection doesn't occur). I'd be interested in seeing any formal theory applied to sleep. As I understand, a genetical component has only recently been identified.

Good answer.

No, I just want evidence that "the brain needs sleep" vs "humans need sleep."

A little serious, a little contradictarian. Obvious answers are obvious, especially without evidence, and especially when evolution is concerned.

I used to think that no one ever died from insomnia. But I saw a Discovery type show recently about people who develop a rare condition where they become unable to sleep at all - not even micro sleeps. They said after about 3 months of this total non-sleep they die.


PairTheBoard

Meh. Any decent engineer would work around the problem.

We do need sleep though. Clearly a problem in product development. I suggest that we let the marketing department to an intensive study about what our potential customers really want.

I like sleep, particularly like feeling sleepy while in bed with no compelling need to get up . Doing this in a synchronized fashion can be good too.

and kids should have a sleep mode switch.

I did hear about a lady who never sleeps, i imagine there are a few people like that, I did hear in the same (radio fun facts announcement?) that we don't actually need sleep, I've never tried to cross reference that though.

You really do have problems when it comes to grasping 0% and what the word 'never' means, don't you? You should fix that about yourself.

I didn't think my answer of being able to afford sleep was that obvious, but maybe maybe it was. It makes perfect sense to me anyway.

We have evolved to be in a hierarchical position where we can afford to spend extended periods of uninterrupted sleep. Or put another way, the less a species needs to spend on hunting or becoming prey itself, the more likely it is to spend its leisure time sleeping and conserving energy.

Side question: Is the amount of sleep you need even passed down genetically?

If it's not, no amount of evolution is just going to make us sleep less, unless a random freak mutation happens and the bearer of that non-sleep-needing brain uses the extra 8 hours a day to **** like a jackrabbit.