6 ms·

So the hypothesis is that mammals need REM sleep to prevent the brain from getting too cold while sleeping, but the hypothesis hasn't been tested yet. If this

by yosito 8y ago

So the hypothesis is that mammals need REM sleep to prevent the brain from getting too cold while sleeping, but the hypothesis hasn't been tested yet. 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.

djsumdog 8y ago
There was also some research a while back where scientists theorized that sleep is also used to clean out the brain: https://www.nih.gov/news-events/nih-research-matters/how-sleep-clears-brain https://www.nih.gov/news-events/nih-research-matters/how-sle... 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.
- eloff 8y ago
  I read an article long ago (I searched now but didn't find it) where a family had a rare genetic disorder that prevents sleep and gets worse with time. The afflicted family members essentially go into an early dementia in their fourties or early fifties that's fatal. I don't know how similar that is to Alzheimer's, but it seems to lend weight to the theory that lack of sleep could be a contributing cause of dementia.
  - jarvist 8y ago
    It's a pretty harrowing story. http://www.bbc.com/future/story/20160118-the-tragic-fate-of-the-people-who-stop-sleeping http://www.bbc.com/future/story/20160118-the-tragic-fate-of-...
    - eloff 8y ago
      Thank you, I think that's the one. It amazes me how whenever I mention an obscure article I once read on HN, someone comes along with a link.
  - BLanen 8y ago
    Fatal Familial Insomnia. It's a prior disease.
    - abrowne 8y ago
      Prion
- ajkjk 8y ago
  I have a pet theory, based on sensations I've experienced, that: 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
  - 2bitencryption 8y ago
    well that's a scary thought, because -- 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.
    - ghthor 8y ago
      You may want to eat less dairy, I've found that milk in particular seems to increase the amount of mucous my sinuses and lungs produce.
    - DrJosiah 8y ago
      You may be allergic to something, and/or you could have an infection. 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!
      - philsnow 8y ago
deleted 8y ago
[deleted]
tim333 8y ago
The hypothesis seems a little unlikely. If REM sleep was to warm up the brain you might think people wouldn't do it in hot climates but I don't think that's the case. 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-ai-gives-robots-ability-dream 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 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 https://news.ycombinator.com/item?id=9736598
- untog 8y ago
  > If REM sleep was to warm up the brain you might think people wouldn't do it in hot climates but I don't think thats the case. Isn't internal body temperature kept constant (or at least the body tries very hard to) irrespective of environment?
  - tim333 8y ago
    The body tries to keep the core temperature constant around the heart and internal organs and will divert blood there and let your feet get cold. I'm not sure about the brain but in a 40C climate say I doubt your head would get cold inside.
    - whatsstolat 8y ago
      I'm not sure anywhere on earth is 40c at night.
    - gpvos 8y ago
      Depends on where you are. In a land climate, days can be searing hot while nights are freezing cold.
      - 8y ago

by yosito 8y ago

djsumdog 8y ago

There was also some research a while back where scientists theorized that sleep is also used to clean out the brain: https://www.nih.gov/news-events/nih-research-matters/how-sleep-clears-brain https://www.nih.gov/news-events/nih-research-matters/how-sle... 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.

eloff 8y ago
I read an article long ago (I searched now but didn't find it) where a family had a rare genetic disorder that prevents sleep and gets worse with time. The afflicted family members essentially go into an early dementia in their fourties or early fifties that's fatal. I don't know how similar that is to Alzheimer's, but it seems to lend weight to the theory that lack of sleep could be a contributing cause of dementia.
- jarvist 8y ago
  It's a pretty harrowing story. http://www.bbc.com/future/story/20160118-the-tragic-fate-of-the-people-who-stop-sleeping http://www.bbc.com/future/story/20160118-the-tragic-fate-of-...
  - eloff 8y ago
    Thank you, I think that's the one. It amazes me how whenever I mention an obscure article I once read on HN, someone comes along with a link.
- BLanen 8y ago
  Fatal Familial Insomnia. It's a prior disease.
  - abrowne 8y ago
    Prion
ajkjk 8y ago
I have a pet theory, based on sensations I've experienced, that: 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
- 2bitencryption 8y ago
  well that's a scary thought, because -- 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.
  - ghthor 8y ago
    You may want to eat less dairy, I've found that milk in particular seems to increase the amount of mucous my sinuses and lungs produce.
  - DrJosiah 8y ago
    You may be allergic to something, and/or you could have an infection. 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!
    - philsnow 8y ago

deleted 8y ago

[deleted]

tim333 8y ago

The hypothesis seems a little unlikely. If REM sleep was to warm up the brain you might think people wouldn't do it in hot climates but I don't think that's the case. 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-ai-gives-robots-ability-dream 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 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 https://news.ycombinator.com/item?id=9736598

untog 8y ago
> If REM sleep was to warm up the brain you might think people wouldn't do it in hot climates but I don't think thats the case. Isn't internal body temperature kept constant (or at least the body tries very hard to) irrespective of environment?
- tim333 8y ago
  The body tries to keep the core temperature constant around the heart and internal organs and will divert blood there and let your feet get cold. I'm not sure about the brain but in a 40C climate say I doubt your head would get cold inside.
  - whatsstolat 8y ago
    I'm not sure anywhere on earth is 40c at night.
  - gpvos 8y ago
    Depends on where you are. In a land climate, days can be searing hot while nights are freezing cold.
    - 8y ago