NOVA

Let me tell you a little bit about sleep.

I like sleep. I do as much as it possible.

But for a long time the utility of sleep has been a question that Science has never fully answered. Different animals seem to need variant levels of sleep. Dolphins seemed to never sleep, until research showed that they were capable of sleeping with one side of their brain awake.

Ducks do the same thing. Watch a duck sleep more closely sometime. On at least one individual in the group you will see the eye facing away from the inside of the group of sleeping ducks intermittently open and close. That side of the brain is partially awake as the other, and always closed eye, is fully asleep. You will know when the duck has hit REM (rapid eye movement) sleep because it's posture will slack.

But the question at hand. Why sleep at all? No definitive answers exist. The common sense one, rest, is not quite sufficient. What is it about the brain wave activity, which the most marked change in our body during sleep, that enhances the rest experienced during sleep?

The logical inference is that sleep is much more for our brain than for our bodies.

And recent the results of recently performed research points in that directions.

A Scientist researching sleep at MIT hooked up electrodes to the brains of mice. Directly hard wired the suckers.



He then put the mice through a maze in search of cheese. The entire time each mouse was in the maze a constant stream of signals was propagated from the brain of the test mouse up through the electrodes and to a receiving unit which translated each signal pattern into a series of dots creating a pixelated image of the electrical activity of the mouse's brain. A snapshot, if you will.

Every time the mouse was at a given point in the maze a similar pattern of dots emerged on the machine. Each time a mouse found cheese similar patterns would appear. This consistency in electrical output allowed scientists to determine where in the maze a mouse was without even needing to see the mouse.

Essentially they could literally read its mind. Like braille.


Of course, at some point the mice would go to sleep. And what emerged was very intriguing.

For the first 10 minutes of sleep there would be a random cycling of dot images that would appear, disappear and re-appear. Then the same pattern would be run in reverse order, and repeated in forward order.

The repeated images and image sequences corresponded directly to the images sent to the machine by each mouse when it was in the maze. Some images corresponded to given areas of the maze, some sequences were the ones that yielded no cheese, and others were replays of the sequence of movements the mouse made when it was successful in finding food.

Essentially during the initial stages of sleep the brains of the test mice were going over the new lessons of the day and it's various experiences. The memories were edited and rehearsed.

The implication is that sleep serves as a method for our brains to rehearse and imprint vital functions and process new information.

And the physical test data in humans echoes the results obtained from the mice.

It would be unethical to hardwire a human being and capture his thoughts. Such are the moral limitations of science. But like a mouse we are mammals. Our brain organization is similar like our functional DNA.

As such it is not a stretch to assume similarities in the chemical architecture of our brains.

People do better on certain diagnostic tests after a night of sleep. A famous test involves typing an identical series of letters and numbers before and after 8 hours of sleep. The average subject increases his performance speed by 50%.

Think baseball, football, singing, math etc, any of these activities, if they are indicated to the brain to be desired as attained skills, may just be imprinted in us during sleep.

So don't slack off on sleeping.