
Goodnight. Sleep Clean - petethomas
http://www.nytimes.com/2014/01/12/opinion/sunday/goodnight-sleep-clean.html
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wging
> One day, scientists might be able to successfully mimic the expansion of the
> interstitial space that does the mental janitorial work so that we can
> achieve maximally efficient round-the-clock brain trash pickup.

We can ask the same question the article poses initially about why we still
sleep. Why hasn't this evolved yet? What are the disadvantages of this
'always-GCing' approach? In a best-case scenario, it might just be some sort
of historical limitation that no longer applies* (just as our tendency to get
fat is a result of an approach to resource conservation that made sense in the
ancestral environment, where food was scarce and opportunities to feed
intermittent, but does not in modern civilization, where food is nearly always
available). In a less appealing scenario there might be some tradeoff that
causes us to think less efficiently when this interstitial space expands.

[*] The extra fluids have to come from somewhere, which would mean they're not
available for other tasks. Similarly, digestion is expensive--blood flows to
the intestines after a meal, and if this is to happen then (since in the short
term, you have a fixed amount of blood) it's less available for fueling your
muscles. (And if you force yourself to be active right after a meal there's
contention for these finite resources. Ever go for a run right after eating?)

Though perhaps there's less fluid involved here than there is with the
intestines.

~~~
ggreer
Evolution is actually quite horrible at engineering. Since it can only hill-
climb, we end up with ridiculous designs stuck in local maxima. Evolution made
video cameras out of jelly, a breathing tube that must be crammed full of
solid foods every few hours, and (as Neil deGrasse Tyson put so delicately) a
sewage plant next to an amusement park. No organism ever evolved radio
communication, or the ability to transmit nerve signals faster than 0.000001c.

Still, why 8 hours of sleep instead of 2? The best explanation I've heard is
famine resistance. Sleep conserves energy; until recently, humans were
calorie-limited. Also, there's probably an advantage to remaining quiet and
still in the dark, when human eyesight is at its worst and predators roam.

~~~
count
Why take human engineering out of 'evolution'? Biological evolution developed
our brain and manipulative appendages, which were then used to make better
video, comms, etc. Humans, and everything we do, are still 'naturally
evolved', by definition.

~~~
ggreer
"How many legs does a dog have, if you call the tail a leg? Four. Calling a
tail a leg doesn't make it a leg." — Abraham Lincoln

~~~
staticshock
Side note: according to some sleuthing by the snopes crowd[1], this quote
predates Lincoln's presidency by several decades, with the first recorded
usage being somewhere around 1834. He may have used the anecdote himself, but
it seems to have been a popular saying in the abolitionist movement in
general.

[1]
[http://msgboard.snopes.com/message/ultimatebb.php?/ubb/get_t...](http://msgboard.snopes.com/message/ultimatebb.php?/ubb/get_topic/f/32/t/000450.html)

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skybrian
I found this oddly phrased:

"the sleep researchers I spoke with agree that there’s no evidence that aided
sleep is as effective as natural sleep."

Is there evidence that it isn't as effective as natural sleep? Why not say
there's no evidence either way?

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bsirkia
It blows my mind (pun intended?) that we still don't really know why we need
sleep, even though we sleep for like 20% of our lives.

We know some stuff, like if you don't sleep, bad stuff happens to your body
and you don't form memories effectively, but like the article says we haven't
figured out why it's so essential.

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anonymouscowar1
20% (4.8 hrs)? I don't know about you, but for me it's closer to 33%.

~~~
bsirkia
Haha ya, I guess that's really on the low end. I was thinking of old people
who seem to sleep like 4 hours a night for the last 20 years of their lives.
Plus people are generally sleep deprived.

~~~
gwern
Old people pretty much are sleep deprived, though. Their systems are falling
apart (that's aging). I was reading a study once on, I think, melatonin in the
elderly, and it showed a graph of the 24-hour melatonin secretion cycle for a
young healthy sample and then for like age 60+ people; in the young people,
the cycle looks exactly as one would expect, with a fall in mid-day, increase
in evening, and high levels while asleep during the night and slowly declining
to the day levels - in the elderly, it was a flat line. Horrifying.

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cdooh
I'm mostly glad that this will help with Alzhimer's(sp?) research. Being able
to work 24hours matters less to me, I rather like to sleep, than treating the
terrible memory loss that comes with the disease.

~~~
k-mcgrady
>> "I rather like to sleep"

Personally I agree. I'd also find it interesting to see how removing sleep
from our lives would effect things like depression or even how it would just
effect people having a bad day. For example if I'm having a terrible day I
can't wait to get into bed, fall asleep and end it. The separation sleep
provides between one day and another gives the feeling that tomorrow is a
fresh start and the problems of today might be less. I'd guess I would be
miserable for longer without sleep.

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sampo
This is by far the most interesting science news I've seen for many months. I
am glad it made the HN front page. (And because of the very non-descriptive
title, I almost didn't click on it.)

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Flenser
I remember watching a series of videos a few years back by a guy who claimed
sleep was for waste disposal and that dreams were because different parts of
our brain were shut down at different times. I can't remember his name or
where I saw it. Does anyone else remember it or have a link?

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agumonkey
Instead of medication assisted sleep, I'll stick to a well organized
environment and rhythms.

Real sleep deprivation is really 'funny', after having an allergic reaction to
something in my home I couldn't sleep in it for 3 days, it's like being drunk
with fever, you lose track of time, balance and get emotionally confused every
30 seconds.

ps: I wish they'd mention 20 minute long naps and how they can feel so
"repleting" even though I don't believe a lot can be cleaned through the
glympathic system.

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nshepperd
I'd be interested to see what effect (if any) modafinil has on this cranial
garbage collection routine. Given subjective reports that modafinil allows one
to go without sleep _without_ accruing sleep debt for some period of time,
maybe this would shed some light either on how modafinil works or what other
functions sleep has (or both!).

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dimfisch
Curious whether meditation might induce a state where the brain also cleans
itself, just like during sleep...

~~~
tripzilch
Afaik, that's how they explain why the Elves in some version of D&D fantasy
roleplaying only need 4h of sleep/meditation :)

But seriously, I've never noticed anything like that in my own practice.
Granted I don't go for stretches longer than about 45 minutes, and I do it
every morning when the cleaning has just happened. Or perhaps you'd need a
specific additional technique apart from just sitting focusing on breathing.
Visualisation techniques can sometimes dramatically change the effect of a
meditation session (sometimes, but not consistently).

Additionally, I suggest trying to meditate when you're mildly sleep deprived.
You'll find it harder to do, with yourself dozing off or blinking/blacking out
occasionally. And while they're both, in some sense, mental states of "no
thought", they are also worlds apart: the meditative state is a state of high
focus, while the dozing/blinked state is pretty much the opposite.

What I've found in the few occasions I've experienced this (I don't like being
sleep deprived so I try to avoid it :) ), is that you come out of such a
blink-out state with a tiny bit of a jolt. Now, say I'd apply the same
technique as one would use for basic meditation practice: when your thoughts
wander away, try to observe that this has happened, congratulate yourself on
noticing (instead of seeing it as failure) and gently bring your thoughts back
to the focus.

Now I guess (and I'd have to try it out, but I don't want to because it
involved sleep-depriving myself) one of two things will happen: One, over time
(weeks/months), this process will train myself not to fall asleep, setting up
circuits in my brain to keep me from dozing off (hopefully only when I don't
want to). Of course the cleaning thing won't happen because you're awake and
focused all the time, so you just got more efficient at sleep depriving
yourself. OR number two, perhaps more likely, you'll doze off anyway, at some
point. I can totally see that happen, dozing off into a half-dream where I
dream I bring my mind back into focus and have this amazing meditation,
suddenly get weird, in my dreams, and wake up a few hours later. It's the
typical kind of trick my brain would pull on me.

Also, I don't quite see meditation like this. True, after 30 mins of
meditating I am usually more relaxed and focused than I was before (but not
always), but the main thing about meditation for me is just like sports and
exercise: it's not so much about the immediate results, but it's _training_.
When I meditate I do it because I am training my mind to keep focus and not
drift off to everywhere except here & now, to have that state at least once a
day, but to also take that habit onto the rest of the day when I'm not
sitting. What you're describing sounds more like meditation as a kind of
"pill" to give a direct effect, I find it's not very reliable in that sense, I
use it more like training one's back muscles to give more support during the
day.

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eruditely
Article title is somewhat misleading, I thought they meant sleep clean as in
without going into an intoxicated state, or to actually sleep clean and that
this was somehow relevant.

"Sleep cleans your brain" or "Sleep garbage collection" or something. Still
probably not good.

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dmd
The first paragraph of this contains my latest pet peeve - any kind of evo
explanation which relates a human behavior or biological process to the
_hominid_ era of evolutionary adaptation ... when that behavior is common to
all mammals or even all vertebrates.

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nsns
Apart from "rebooting" body and mind during sleep, I also think that dreams
are extremely important as real life's sandboxing; used to evaluate the
efficacy of future actions and prepare for them.

~~~
tripzilch
... the future's gonna be _weird_ ...

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elwell
That brain graphic is like a motion illusion when I read down the text; it
continually appears to shrink. Did anyone else see that too? It only works
when you aren't focusing on the graphic.

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frik
Interesting article.

Off-topic: the new nytimes.com website feels a bit buggy on my iPad. None of
the top banner button works (of the article page). Are they using JQuery-
Mobile or similar slow js framework?

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3825
jQuery v1.7.1 as far as I can tell

[http://js.nyt.com/js2/build/sitewide/sitewide.js](http://js.nyt.com/js2/build/sitewide/sitewide.js)

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rushi_agrawal
Let's all just sleep properly, till someone finds a pill which will rejuvenate
us in lesser time, and we fool humans overuse/misuse it and crib about
technology later :)

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nazgulnarsil
why would staying quiet and motionless during nocturnal predator hunting time
be an evolutionary disadvantage?

~~~
k-mcgrady
Because you are also completely defenceless. If a predator stumbles across
you'll probably already be in pieces by the time you're aware what's
happening. Ideally you would want to stay quiet and motionless but also awake
and alert.

