Sleep Update?

[Guest guest]

This article from ABC News adds more information to the material which we

raised some months ago on the quantity and quality of sleep:

<http://abcnews.go.com/sections/scitech/DyeHard/dyehard.html>

I have included my comments at relevant points in the text. Any other

comments?

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Critical Hours

A new study finds sleep is critical for learning new tasks

Study shows why Getting Up too early may be Counterproductive

by Lee Dye

Special to ABCNEWS.com

July 3 - The wannabe super-achiever who spends too much time getting ready

for the big day at the expense of getting enough sleep is probably doing

precisely the wrong thing.

Researchers at Harvard University have found new evidence that the brain

continually reorganizes itself while the host is snoozing away. A nap in the

afternoon probably boosts performance, but it's no substitute for getting a

full night's sleep because those last couple of hours of slumber are when the

brain tells itself to pay attention to what's going on.

It is during that critical phase that the brain sends " funny looking wave

forms " that tell some brain cells to beef up their connections with other

neurons, says Mathew of the Harvard Medical School's department of

psychiatry. , lead author of a report published in the July 3 issue of

the journal Neuron, says those wave forms apparently work as " powerful

triggers " that tell our brain something we've been working on is important,

thus improving our performance the next day by committing a learned skilled

to the memory banks.

Honing Skills in Your Sleep

That electrical activity, called " sleep spindles, " can be measured, and the

research shows that spindles abound toward the end of the sleep period.

" It just so happens that when you track the amount of these spindles that the

human brain has during the regular eight-hour period of sleep, they seem to

ramp up and have very high intensities in the last two hours of the night, "

says. " It's specifically those two hours that we have found to be most

important. "

[Did this group study any subjects who usually require far less than 8 hours

of sleep daily, yet still manage to function very efficiently? Also, is that

two hour phase actually that precise and characteristic or does it vary

between something like 30 minutes for some people to 3 hours for others? Mel

Siff]

So the person who hops out of bed after six hours sleep and goes forth to use

newly learned skills to slay a dragon has managed to shut down that critical

phase of mental activity just as it was getting started. His new skills

likely won't be nearly as potent as they might have been.

Significantly, this apparently applies to a wide range of human endeavors,

from playing a musical instrument to hitting a golf ball to pounding on a

keyboard. All of those depend on something scientists call the " procedural

memory system, " and it involves learning all types of skills.

For part of the research, and his colleagues took 62 right-handed

persons and asked them to type a sequence of numbers (4-1-3-2-4) with their

left hand as quickly and as accurately as possible. On average the

performance of the participants improved about 60 percent just by repeating

the task over and over.

[Can one validly compare these rather trivial tasks with the far more complex

tasks of writing a classical music piece, learning a play by Shakespeare or

solving some of the mathematical equations in advanced physics? Why didn't

they use a learning task which did not only depend on eye-hand coordination

and which relied more on memorising a long new passage from a book on a

non-trivial subject? I know that this research is a start, but any

limitations should have been clearly stated. However, I am sure that the

researchers concerned would have stated that this work was preliminary and

that the journalist was being a little more creative in reaching the

conclusions in this article. Mel Siff]

Nap Minimum: One Hour

The participants were then divided into subgroups, and one group was tested

again after staying awake for 12 hours. They showed no improvement. But when

tested after a full night's sleep, they improved by 19 percent.

Another group improved by 20.5 percent after a night's sleep, but gained only

2 percent after staying awake for 12 hours. After a full night's sleep, their

performance jumped again by nearly 20 percent.

Other research showed that the improvement in performance was directly

related to the completion of a full eight hours of sleep. The last two hours,

says, turned out to be the most important.

[This sounds unnecessarily precise and deterministic - there are many top

rate scientists and workers in other " thinking " professions who are extremely

efficient and creative thinkers on considerably less sleep than that. There

are also many of us who feel exhausted, slow-witted and somnabulant if we

sleep more than about 6 hours a day. It must be a complete miracle that

any of us who sleep far less than 8 hours a day ever completed higher degree

studies or achived much in any thinking aspects of life! Did this study not

take into account any individual variation - surely, it would have been a

more valuable study if the scientists had concluded that the last 20% of

sleep are vital for enhancing a certain type of mental processing? Mel Siff]

In a related project, other Harvard researchers found that a midday nap does

much to recharge the system by allowing the brain to consolidate the memories

of habits, actions and skills learned during the day, according to

Stickgold of the department of psychiatry. A nap, he says, gives the brain a

chance to avoid " burnout " and reorganize itself, perhaps bringing new

circuits in to relieve some that had grown weary.

[Has it ever been shown that neural tissue can " burn out " ? We know that

excessive stress can cause structural and functional dysfunction of muscle

and connective tissue, but has anyone ever shown that too much thinking or

wakeful activity can compromise the integrity and function of neural tissue?

Is this remark anything more than conjecture? Mel Siff]

That short of a snooze, however, is no substitute for a full night's sleep,

the researchers say.

And to be much help at all, the nap needs to be about an hour long. Try

explaining that one to the boss.

This is still a relatively new field, and much remains to be learned about

what the brain is up to while we think it's just sleeping, but what is

emerging loud and clear is the fact that sleep is far more critical than most

of us might think.

Sleep = Work

We may think our brain is " dormant " while we're asleep, says, but it's

actually firing off commands and doing all sorts of things to restore our

biological systems to good working order.

" You spend about a third of your life asleep, and I don't think mother nature

is stupid enough to keep you asleep for a third of your life to do just one

thing and one thing only, " like rest your weary bones, he says.

" You don't spend two thirds of your life awake just doing one thing. You do

many things while you are awake. "

Researchers are finding, he says, that parts of the brain are as active when

we are asleep as when we are awake. "

And the new research suggests that if we cut back even a little on our sleep,

we're reducing the brain's ability to commit what we have learned to memory,

whether it's typing, designing a rocket engine, or learning a new dance step.

It's enough to give you nightmares.

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Dr Mel C Siff

Denver, USA

http://groups.yahoo.com/group/Supertraining/