Personally I agree with Marcus Schmidt and his idea of "energy allocation function of sleep". Basically it says that distinct physiological states provide viable configurations of priorities for vital functions that allow for the lowest possible energy expenditure over the whole cycle. I.e. there's no single specific function of REM sleep, it hosts all functions that are too costly to prioritize during other states, and the same is true for NREM.
I wonder if there are universal laws that transcend biology and technology, all following the same rules that we haven't figured out yet.
I'm not saying its not fascinating though. It is incredibly fascinating, and this kind of research is exactly why we should be investing MORE not less in pure science.
I disagree. Look at the paper: https://www.cell.com/current-biology/fulltext/S0960-9822(18)...
Can you point out where they even report the temperature of the brain/brainstem? This looks like it is just wild speculation.
Indeed, it’s natural that we do this but kind of funny when you consider that our machines now have their own circadian rhythms in tune with ours.
What might our IT infrastructure look like if humans evolved to sleep far less or not at all I wonder!
Sounds like your typical developer or sysadmin to me, so probably not much different at all. ;)
We probably would have started with multi-core systems much sooner.
It's not amusing in a bad way, it's not ridiculous. I mean to say that it's highly surprising and counterintuitive, like a punchline in a joke. Most theories about REM are focused on brain function, as is almost all research on it. Chaperone production, though, is a basic housekeeping routine. Saying "well, REM isn't about episodic memory consolidation or dreaming or wherever you might think, it's an epiphenomenon of a very low-level mechanism that prevents boiling alive" is almost as unorthodox as claiming that learning to code is about forearms' dexterity.
If this turns out to be true, I wonder if it has implications for night terrors. It seems plausible that if the brain fails to warm enough through REM sleep, hormones are released to wake the brain up completely which lead to night terrors and the adrenaline rush feeling that accompanies them.
These are just hypotheses, but interesting nonetheless.
Maybe it's more like the "Google’s DeepMind AI gives robots the ability to dream" stuff that increased their neural nets rate of learning 10x https://www.extremetech.com/extreme/240163-googles-deepmind-... and "Rats Dream About the Places They Want to Explore" https://news.ycombinator.com/item?id=9791927 - about improved cognition.
Also the 'inceptionism' stuff looks so reminiscent of human dreams that it makes me suspect there is neural network stuff going on rather than heating. https://news.ycombinator.com/item?id=9736598
Also, fever dreams.
Isn't internal body temperature kept constant (or at least the body tries very hard to) irrespective of environment?
It could mean that constant sleep deprivation could increase the risk of Alzheimer's, but of course that's really difficult to test since you'd need a lifetime of sleep data for humans in their 60s/70s.
Also I think that paper was just about sleep in general, not specifically dreams/REM sleep.
It's a prior disease.
A. 'sleep cleaning the brain' is real
B. The things that are expelled from the brain are expelled through the sinuses
C. If you are sleep deprived enough, you can feel this process happening while you're awake
The blood from your brain (like all your blood) is cleaned by your kidneys and liver.
Are you confusing those with the sinuses in your nose? Two very different kinds of sinuses.
Lymphatic system does connect to the circulatory system, so can eventually be handled by the kidneys, liver, etc. But it's not necessarily a direct path, according to recent research.
my mom's side of the family has a continuously running history of early-onset Alzheimer, AND terrible sinus problems.
my sinuses are expelling so much goop on a constant basis that by the end of the day my teeth are covered in a layer of slime.
A 3x former coworker and friend had a sinus infection that wouldn't go away. Like 10 years. Had his tonsils removed, etc. He finally cut out everything in his diet, and eventually discovered that despite not being gluten sensitive, celiacs, crohns, IBS, etc., or allergic (he got the allergy scrapes too), not eating bread / barley / wheat was the thing. Whether it was bacterial, fungal, or 'not allergic unless I eat it' type thing, the answer was the same: change your diet, write everything down, see what happens.
Another family friend who had sinus issues and allergies for 30+ years ended up going keto. In the process of losing 20 pounds (in the last 4 months, so far), she also is no longer allergic to Norwegian spring/summer. Don't know if it was the sugar, starch, etc., but low/no carb basically changed her life.
Note: I'm not a medical doctor. The above are anecdotes. But changing your diet could seriously change your life. Give it a shot!
if any reader wants to go this route, "whole 30" is a relatively well-known "elimination diet" that omits the vast majority of the things that cause food sensitivities in people. the idea is you do a 30 day purge with an allow-list of foods, and after that you can slowly reintroduce individual things and keep track of how you feel.
a benefit of using a well-known diet over any other one is that finding recipes etc is much easier when there's an entire subculture of "whole 30" food bloggers.
I have gone through periods of high and low amounts of sleep for both work and personal reasons.
Sleep has always been phrased in terms of time - ie get x hours of uninterrupted sleep to perform your best. But there has to be more to it than that.
I've stayed up all night and felt rejuvenated the next day. And I've had lazy Sundays where I've remained tired the entire day.
I might not have not seen the scientific study on it yet, but I believe the quality of your sleep has a lot to do with the nature of when and why you're sleeping as well as your mental state when doing so.
Sometimes I want to stay up all night and keep going the next day. Other times, I go to bed at 9 and get up early the next morning. Sometimes I only need a couple of naps. Other times, I want to keep on sleeping, which I allow myself to do.
I have slept for 20 hours straight before, with only short breaks to pee and drink water. I think this typically happens when I contract a cold or flu, and helps my body focus on fighting it off.
I feel much, much better than when I used to have to be at the office every weekday, even if I could come in at noon.
And I've observed this to be true in my life. The most peaceful, restful sleep I experience is consistently between 10pm and 1am.
I fully agree with your dismissal of hours slept being the quantitative unit of sleep, and I'm similarly curious about what constitutes a healthy, effective sleep habit...
I don't know about some people, but for me this is practically the silliest thing I've ever heard.
I need 8 hrs of sleep period, and the time of day has zero effect on my alertness. It can be 9pm-5am or 3am-12pm, it's exactly the same.
But if I get only 6 hrs of sleep? I'm miserable.
I can't even begin to imagine where the idea that the hour of the day matters would have come from.
And just think of nighttime workers. Obviously their daytime sleep counts...
The idea that sleeping in is lazy and self-indulgent while rising at dawn is virtuously ascetic?
Many bodily functions such as hormone production are affected by your circadian rhythm . Ambient light also seems to have an effect on quality of sleep.
It matters a lot, especially if it’s 5 AM - 1 PM. In high school, I was an RF technician, testing the rollout of LTE in my area. We had to conduct drive tests at night, due to traffic concerns. Working at night and sleeping during the day seriously disrupts your natural circadian rhythm. The only reason we as humans don’t sleep immediately after sunset is due to the invention of artificial light.
I think the quote is more an aphorism than rigorous guide. The framers of the quote probably didn’t anticipate the night shift ;)
“Ayurveda medicine is considered pseudoscientific.”
Early thought systems evolved from hundreds of generations of folk wisdom. There are significant enough gaps in modern scientific understanding that to discount these systems is foolish.
Note that the current discussion is set in such a gap.
That said, I'd take science-driven modern medicine over weird herbs and rhino horns any day of the week.
For the work they do this is good though, in the summer there are a lot more things to do, whereas in winter when it’s -20c and the ground is covered in snow, there isn’t very much to do.
In a way I think they have it better than me, trying to go to sleep when it’s still a bright sunny day outside just feels weird.
As a person who induces lucid dreams as a hobby, I sometimes manage to make use of those long lazy mornings on weekends to lucid dream. I've found it's very difficult to have a lucid dream in the first two or three sleep cycles. After that, it's much easier because the REM stage of sleep is longer. Not that I've found that having lucid dreams is easy, I get one day like that every month or two and a spontaneous one here or there in between.
I have benefitted immensely from yoga and parts of ayurveda and I laugh at people who dismiss them but I don't like them being cherry picked and tested which diminishes trust in them
If you go long enough without needing to be on a schedule, studies have found a lot of people move back into a rolling/rotating sleep cycle .. a few hours at a time throughout the day/night. I found myself doing this while I took a several month sabbatical from the workforce.
Define "need". Also, citation needed.
Just because you can get away with it and live, doesn't mean it's the best move.
“In 2009, a woman came into Ying-Hui Fu’s lab at the University of California, San Francisco, complaining that she always woke up too early. At first, Fu thought the woman was an extreme morning lark – a person who goes to bed early and wakes early. However, the woman explained that she actually went to bed around midnight and woke at 4am feeling completely alert. It was the same for several members of her family, she said.
Fu and her colleagues compared the genome of different family members. They discovered a tiny mutation in a gene called DEC2 that was present in those who were short-sleepers, but not in members of the family who had normal length sleep, nor in 250 unrelated volunteers.
When the team bred mice to express this same mutation, the rodents also slept less but performed just as well as regular mice when given physical and cognitive tasks.“
For instance in the US today childhood injury and fatality rates have plummeted . And this seems like an obviously good thing. And one might reasonably hypothesize that the increase in rules and regulations against letting children play independently, as well as the rise of helicopter parenting has played some substantial role in this. Since it's very easy to see the link there.
Yet at the same time other factors such such as childhood mental illness, obesity, and other major issues have sharply increased. Relative academic results are down and even IQ levels are declining. Are these linked to the behaviors that have driven the decrease in injuries in fatalities? Well that's a lot harder to say, though I think it's a very reasonable hypothesis that at least some of these issues are linked with the same behaviors that have reduced childhood injury/mortality rates.
This is a recurring pattern in many things. Our understanding of the causality of genetics right now is essentially 0 keeping in mind that saying gene A 'causes' effect B is no more a meaningful understanding of the reason for the causality there than saying rain clouds cause rain.
 - https://www.childtrends.org/?indicators=unintentional-injuri...
Of course sometimes it doesn't have that effect, but I've managed to repeat it 2-3 times and I know for a fact that simply being awake in the middle of the night and going back to sleep again doesn't have that effect.
1. 0.1mg is an effective dose.
2. It is probably beneficial to take it every night before sleep.
Sidenote: The book recommendations on HN are always top notch.
The Promise of Sleep is an okay book, but it is almost 20 years old now and it shows.
I have read both books and it is remarkable how much more we learned in the time between them.
I am a better co-worker, family member, client etc with sleep.
They should look at aggression in animals rather than how well they do tasks.
The facts are interesting, the conclusion doesn't make any sense at all to me.
>These marine mammals have evolved a half-brain style of sleeping, perhaps as a way to remain alert enough to avoid predators and drowning.
>Because part of the brain is always active, it’s always warm. As a result, it never triggers R.E.M. sleep.
(But I'm no expert.)
In what sense is it inefficient? In terms of energy 100% is converted to heat anyway
There is a paper where some researchers look at biological processes vs computer software. Biological processes seem to have a lot of repetition between systems:
There's also the issue of the blood-brain barrier. Might make normal thermal regulation insufficient. In any case, it seems like they intend to do further study to see if this hypothesis is really correct and if there is more to the story. Who knows--it might be that for some species it's not necessary, but left over as a vestigial behavior like a tailbone. That's pure conjecture on my part, excuse me.
Something I find interesting about this, if a little off-topic, is that the Ancient Egyptians had a misconception that the brain simply existed to cool the blood. When they mummified a body they threw that part in the trash. How far we've come.
I've heard a lot of office buildings will leave every floor's fluorescent lights on in the winter to take a load off the overnight heating bills. I'm sure that lessens the lifespan of the bulbs and ballasts, but for people to adopt that practice it must still be economical in the final tally.
Who knows, I'd love to see more study on this because I think everybody in history has always wondered what the hell is up with dreams. "To keep your noggin warm" seems like a super anticlimactic purpose and I love it. It's so absurd and nihilistic it's funny, which kind of jives with nature's whole style.
I couldn’t agree more and wouldn’t it be so indicitave of the scientific trend that ensmallens man?
From the center of the universe, the sun orbiting our land to the Big Bang and inflation theory where there is no center.
From gods chosen creation to common ancestors shared with apes.
Now even our dreams to be punctured?
Brilliant to think about!
Consider the developmental paths of cell differentiation/specialization over the evolutionary history of animal species. Neural cells and muscle cells both have a common progenitor cell (i.e. a stem cell will differentiate into this cell, which then has one or the other as potential descendants.)
This sort of means that there is "code sharing" going on between the structure of nerve and muscle cells, moreso than between these and, say, liver cells. And, since animal muscle cells evolved before animal nerve cells, it's likely that it's directional—it's less that these are two "classes" with a common, well-factored "parent class"; and more like nerve cells are a "subclass" that has something closer to muscle cell functionality in its "parent class", and overrides that functionality heavily until it does what it wants.
Or, to put that another way: ignoring the particular way nerve tissue structures itself, and the receptors it grows, etc. Functionally, nerve tissue is, effectively, just muscle tissue that is balanced very precariously by its electrochemical environment to be in an always semi-conducting state, where the tissue as a whole will never go all-the-way-resistive (that's excitotoxicity, both in muscles and in nerves) or all-the-way-conductive (that's flexion in a muscle; but that's a seizure in a nerve. For the nerve-as-muscle, that's okay, it's built for that; but for the nerve-as-controller-of-functioning-elsewhere, that messes things up.)
Nerve cells rely on a lot of the code they've "inherited" from their muscle-cell "parent class" for their functioning. This includes the part where muscle tissue (and so nerve tissue) gets oxygenated by pumping its own blood through it [and clears waste by pumping its own lymph through it], by inducing subtle sinusoidal increases/decreases in electrical activity to cause increases/decreases in capillary diameter.
This is especially important for the brain, given that the blood-brain barrier prevents blood from being "driven" through the brain by the heart. The brain has to pump itself, and therefore has to induce electrical activity in itself.
For the brain-as-muscle, this electrical activity is useful. For the brain-as-neural-network, this electrical activity is—from what I understand—a form of interference to the signal the brain is trying to propagate/compute. The brain has evolved to deal well enough with this interference to make it not get in the way of accomplishing the goals the brain was evolved to accomplish; but, necessarily, evolution never bothers to go any further than that. So, as long as the effects are "harmless" to adaptive fitness, that interference is allowed to leak through as a signal interpreted by the brain-as-neural-network as thought, or perception, or what-have-you.
And thus, dreams.
i was remembered of that very rare condition where your brain cannot ever enter the deeper sleep states. these people usually die rather soon after onset of exhaustion. what has been confirmed through these people is that narcotics dont help at all. while you can ise it to make them 'sleep' long enough, it's not helping with the condition. so brain warming cannot be the main reason for REM, if it's one at all.
edit: fatal insomnia is what i was referring to.
> In those earlier studies, researchers kept animals from going into R.E.M. sleep by waking them up. “In some experiments, they wake up the animals a thousand times a day,” Dr. Siegel said.
So much science that I used to take for granted is garbage.
As a society we need to realize that studies are not "proof". The scientific process is more than just studies.
This article is actually fairly balanced in comparison to many of the other paper-based news write ups I've seen.
"Imagination drew in bold strokes, instantly serving hopes and fears, while knowledge advanced by slow increments and contradictory witnesses."
"We have two observations of X when Y"
"So Y causes X!"
"I didn't say that."
"Hey everyone! Y causes X, probably."
Quick, get your own Z, it helps prevent Y...
It is often valuable to question how you know what you know.
You can't eat mathematical proofs.
It's not an ideal solution but it's a practical inevitability to make some assumptions to get things moving. The best of us come back and check the assumptions as soon as they are able to quantify them and perform an empirical experiment, and as a backup we have others independently verifying people's assumptions by trying to replicate experiments and seeing if the predictions line up.
Nobody has magic powers to divine truth from nothing. Science is a filter which gradually strains out the misinterpreted and the biased and the just-plain-wrong, but it still starts with subjective observation and reasoning. As does all human experience. The important part is that it moves away from that instead of stopping there.
Here's a very simple example:
- How much testing is sufficient? For example, as far as we can tell the laws of physics don't vary over time scales that we can directly observe. This has been true as far as we can tell.
- So far so good: the hypothesis that 'the laws of physics don't change' has been 'tested'. Next question: is that amount of testing sufficient?
- Well, that seems to be an untestable proposition; it's always philosophically possible that things get pulled out from under your feet, and no amount of testing up to time T lets you know with complete certainty what happens for t > T.
Go even one or two steps deeper, and you quickly find yourself resting on either unfounded, untested, or untestable assumptions.
"The real sciense[sic] should contain ONLY the things which are proved with real proofs!"
As in mathematical proofs. You can't prove most things the way you can in mathematics, which is rock-solid through tautologies and self-consistent abstract models. When you are observing actual reality you have to make some assumptions.
Obviously this has caused harm, but it's difficult to isolate how much of that harm (if any) is caused by lack of REM when the dips in oxygen saturation could easily be the causing most of the problems.
At some point the brain needs to clean out molecular by-products, replenish stores of needed neurotransmitters, I'm sure at some level there's some garbage collection going on, maybe mark and sweep everything out of short term memory that's been moved to long term. Maybe dreaming actively helps us to connect disparate thoughts and concepts into some kind of of aggregate.
Some of my best thinking comes easily after a great nights sleep...
Without REM sleep (deep sleep does not work by itself), you lose control of your emotions in 2 days at most. You go insane between 1 and 2 weeks (mania, depression, and likely quick switches between those 2), and your body will physically shut down and die a week or so after that. (note that in humans it hasn't been well established that death occurs, for obvious reasons. In mice, however, it's well studied and accepted. No sleep for ~10 days, half of the mice just die).
This seems to be a bit at odds with the idea that it's just a brain warming technique.
If you want to have a peek, you can read about the Wada Test https://en.wikipedia.org/wiki/Wada_test . (And somehow related https://en.wikipedia.org/wiki/Split-brain )
If it does appear in humans, it'd probably be best to study those with extreme insomnia or people who claim to have very short sleep patterns (<2 hours a night) or maybe those who are narcoleptic (the other end of that scale).
The sentence is poorly worded, because when a human is in water, it's an animal in water. Through that lens alone it makes no sense.
I wonder if the modern (American?) trend of running heating at night is affecting people's sleep?
As a Briton who moved to the USA a few years ago, I found the American habit of running heating overnight to be very odd - as I think most Europeans do. In Britain, we tend to run heating only during the day, unless it's extremely cold outside.
It just makes you tired, no matter how much sleep you get.
I read somewhere (?) that the body cools during sleep. Somehow one of the implications was that taking a shower before sleep can help you sleep faster.
The fact that a body is sweating indicates not necessarily that it is hotter than during the day; it could be that the body is trying to be cooler than it was during the day. (Of course, if you wake up feeling hot, it's probably because you're hot.)
Thermodynamically, it makes sense that being in a bed, with insulation against almost all of one's body, would (once the insulation gets warm) leave someone warmer than when they're sitting or standing -- at least if the ambient temperature is the same in the day and night.
“R.E.M. sleep might be a trait evolved to keep your brain warm at night”