9 Groundbreaking Discoveries About Sleep

  • Added:  5 months ago
  • There's a lot about sleep that we don't understand, like why we even sleep in the first place, for example. Here are some amazing discoveries biologists have made while trying to solve the mystery of sleep.

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    Brain activity

    Brain centers




    Blue light


  • Video CategoriesEducation
  • Runtime: 10:35
  • Tags for this video:  SciShow  science  Hank  Green  education  learn  sleep  fatal familial insomnia  insomnia  thalamus  human body  health  memory  brain  rem  eeg  brain wave  constantin von economo  brain stem  hypothalamus  sleep science  biology  narcolepsy  chronic pain  fibromyalgia  sleep deprivation  blue light  wavelength  melatonin  light  astrocytes  spinal fluid  medicine  alzheimers  

Comments: 1 531

  • Mikayla Eckel Cifrese

    Can medication help people with that type of insomnia?

  • Bob Bobson
    Bob Bobson 6 days ago

    It would be nice if the word "believe" could be replaced by "think". For instance "that discovery led scientists to think that sleep is..."

  • Rock Balancer
    Rock Balancer 8 days ago

    number 7 he says with that background.... with my screen on max... in the dark... i should go to sleep

  • Cindy Durán
    Cindy Durán 14 days ago

    Poor rats 🐭.

  • Melissa Corzo
    Melissa Corzo 15 days ago

    my favorite activity is sleeping

  • Yash Agarwal
    Yash Agarwal 17 days ago

    my braining is learning about it self.....thug life😎😎😎

  • D.E.B. B
    D.E.B. B 17 days ago

    Perhaps the biggest myth, is that you're unconscious when you're asleep. Not so; you're just in a different state of consciousness. You will respond to a crying baby, phone, an itch, pain, alarms, someone trying to break into your house, etc..

  • Mireille
    Mireille 19 days ago

    "Rats had a harder time healing burn wounds" I wonder how did they tested that poor fellas

  • shorea27
    shorea27 23 days ago

    Oh man, poor rats.

  • Salvator Merrifield
    Salvator Merrifield 27 days ago

    why is that spot below his throat censored?

  • T.W. Someone
    T.W. Someone 29 days ago

    talking without pauses is kinda difficult to listen to

  • kit ten
    kit ten 29 days ago

    if this whole video is about sleep, why didnt you guys talk about too much sleep?

  • Issac Lumbard
    Issac Lumbard 1 month ago

    What about sleeping too much?

  • WWZenaDo
    WWZenaDo 1 month ago

    Ancient humans couldn't get much sleep - plagued by parasites & biting insects, uncomfortable nests or sleeping on branches, having to keep one eye open for tree-climbing predators (like leopards, pumas, snakes, etc.) - all of those survival issues meant they couldn't get a good night's sleep very often. Even cave dwellers had to deal with bugs, snakes, scorpions, etc.

  • WWZenaDo
    WWZenaDo 1 month ago

    Oh, poor little rats...

  • cass c
    cass c 1 month ago

    why have scientists been burning rats?? 😔

  • Mario Capistran
    Mario Capistran 1 month ago

    nothing groundbeaking here

  • CindyMzLuciLulu
    CindyMzLuciLulu 1 month ago

    Is too much sleep bad for you?

  • Reymart Abude
    Reymart Abude 1 month ago

    I want to record my dream while im having a wet dream

  • kittcat223
    kittcat223 1 month ago

    I thought when I was a sleep my sole would. leave my body. -_- .?dose that really happen

  • kittcat223
    kittcat223 1 month ago

    I thought when I was a sleep my sole would. leave my body. -_- .?dose that really happen

  • Ryan Lundgren
    Ryan Lundgren 1 month ago

    I fell asleep to this and i have ridiculous insomnia. hahah

  • Julia Gustepa
    Julia Gustepa 1 month ago

    I sleep up to 10 hours per day and I'm very pain sensitive. I wish I could find out if I'm simply sleeping wrong or need even more.

  • Jahquan Russell
    Jahquan Russell 1 month ago

    What's in my tears

  • [firstName] [LastName]

    im watching this while not sleeping

  • Victor Rodriguez
    Victor Rodriguez 1 month ago

    Is he seriously going to say scientists don't know why we have to sleep. Isn't it obvious?

  • Detailed Obscurity
    Detailed Obscurity 1 month ago

    People actually get paid to work in a lab electrocuting rodents.

  • Kitty Cat Kiss
    Kitty Cat Kiss 1 month ago

    Currently watching this at 4am.. (:

  • Trigon Playz
    Trigon Playz 1 month ago

    My uncle played angry birds epic 48 hrs straight.. he did not die YOU LIEED

  • The Trident Gamer
    The Trident Gamer 1 month ago

    Was the host wearing a TRIFORCE t-shirt?

  • James August
    James August 2 months ago

    after seeing the background pic at 6:05, insomnia may be a problem tonight.. Also, Uberman? Where does that fit? I read somewhere where people were on that schedule for 6 months+

  • Fresh M3
    Fresh M3 2 months ago

    Sleep = memory consolidation, and astrocytes cleaning out your brain because you know... the BBB is pretty tight. Generally everything else that you stated in this video is in response to this. Hopes this helps people that like facts. Sleep doesn't use a pain system, you have a little guy in your brain that paralyzes you PAG, Periaquaductal Gray I think (been a while since 1st year of medical school)... Everything uses the same pain system because it uses your pain fibers and your pain tract. Until you get into the CNS pain that you have to use weird things for... but I'm going on a tangent.... Memory consolidation, astrocytes. Just go with that and no one in science/medicine will ever question what you say.

    Edit: I just got to number 8.... and realized he said Astrocytes lol... Whoops...

  • Plum_ Pie
    Plum_ Pie 2 months ago

    whenever go hiking and i only get like 4gours of sleep in the forest i wake up feeling more rested then i wuld ahve if i was at hme gettig 8hours

  • Tha Spectator
    Tha Spectator 2 months ago +1

    Guys I'm very close to dying I got to sleep at 1:00 and wakeup at 5am. No wonder why I can't remember shit and I have Chronic Neck Pain. I'm going to sleep before it becomes my last time.
    *Good Night*

  • PrettyLittleArii
    PrettyLittleArii 2 months ago

    Lmao and im watching this video at 3am...

  • Tagger Tag
    Tagger Tag 2 months ago

    The horrible shit we humans did to animals for science.. We owe Rats in particular an apology. God will punish us all.

  • 3majsie maciek
    3majsie maciek 2 months ago

    10:05 Milking a cow!? Did I guessed it?

  • Hestia St. Olympia
    Hestia St. Olympia 2 months ago

    "-a region of the brain called the hippocampus."
    First thing I think of
    I actually didn't know we had hippocampi in our head.
    Hmm... I'm calling mine Rainbow.

  • Tsen Animation
    Tsen Animation 2 months ago

    my friend believed that his classmate can be awake for a month without sleeping

  • 8000 cats
    8000 cats 2 months ago

    Lmao, when I first clicked on this video, I thought it said "9 Groundbreaking Discoveries About SHEEP" Counting sheep lol?

  • Saadman Yasar
    Saadman Yasar 2 months ago

    Rats everywhere

  • jeaniebird
    jeaniebird 2 months ago

    I didn't sleep for 6 months straight, once. I went insane, eventually landing in the local loony bin. It was hell. Doctors never figured out, or never admitted, why. I'm positive it's because they kept trying new drugs on me and I just kept reacting badly. After 3 months I had to start refusing because I just couldn't take the side effects, anymore. 3 months after that, I finally slept... Hmm

  • jeaniebird
    jeaniebird 2 months ago

    I had to reschedule a back tattoo I had going once, because I didn't get any sleep the night before. It was ten times more painful than usual. After an hour, I just couldn't take it anymore. I was shocked how much of a difference that made.

  • Jon Lopez
    Jon Lopez 2 months ago


    if jmkjn

  • Beef Shishkabob
    Beef Shishkabob 2 months ago

    I don't understand how "we don't know why we sleep" but 30 seconds later he says we sleep so our body can rest. Isn't that the reason why we sleep? Someone please clarify

  • Christian Andrade
    Christian Andrade 2 months ago

    Why are we so mean to rats?

  • KarinARTS
    KarinARTS 2 months ago

    What's funny is that I'm watching this to force myself not to sleep.....

  • Turtletech Inc.
    Turtletech Inc. 2 months ago

    The hippocampus, where all your memories about hippos are stored

  • Entity 303
    Entity 303 2 months ago

    You can use blue light filter apps to use your phone during night without disrupting your sleep cycle.😀📱

  • 1 For The People
    1 For The People 2 months ago

    Good video! ?Could you please do a video about dishwashing? Sounds mundane I know, but my partner and I are having controversy over hand dishwashing vs dishwasher machine and the temperature of hot water. I say sterilizing hot water has to be at least 165degrees F in which you could not handwash dishes because it's too hot. However if you handwash the dishes with a good soap well, rinsed in cool water the dishes are just as clean if not better than in a dishwashing machine. Sterilizing dishes in a machine is OK but wouldn't you also have to keep them in a sterilized environment? Thank you for sharing. Keep up the good work.

  • bradOLF pittLER
    bradOLF pittLER 2 months ago

    it'd be hard to discover all of this stuff without animal testing.

  • Saleem Al-Agha
    Saleem Al-Agha 2 months ago

    i think wifi interferes with sleep

  • offspring
    offspring 2 months ago

    watching cat videos in the middle of the night?? meeen i did it sometimes

  • Elizabeth Shaw
    Elizabeth Shaw 2 months ago

    I have horrific iretractable chronic pain which is not fibromyalgia. it is exhausting and I need to take a nap in the afternoon and I need 10 hours sleep at night or the pain explodes beyond what I can stand.

  • alex parada
    alex parada 2 months ago

    I dont sleep cuz sleep is the cousin of death *thug life music and glasses then dies*

  • SirMan McDude
    SirMan McDude 2 months ago

    So being in non-REM sleep is where your brain files away and stores what it deems to be important while REM sleep is the brain saying "Fuck it, let's run some simulations 'cause we're bored"

  • LittleMissGamerGal
    LittleMissGamerGal 2 months ago

    Dont look at devices a few hours before bed... yet im watching this before bed. i wouldnt have learned that unless I was exposed to blue light now..

  • Fernando Alatorre
    Fernando Alatorre 2 months ago

    It seems to me a bit naive to say "we don't know why we sleep" and on the other hand being so certain about all of the counter effects of not sleeping. Could it not just be that your body does that (sleeps) so that those terrible, fatal counter effects don't happen? Could it not be that your body knows (in a very broad sense of the word) that those effects will occur and thus intends to prevent them by sleeping?

    I mean the guy in the video says, we don't know why we sleep... and then immediately after he says, a lack of sleep will literally kill you....

    So maybe we sleep so we don't die?

  • Private X
    Private X 2 months ago

    Ok. Good night.

  • ordinary Oddball
    ordinary Oddball 2 months ago

    I have f.lux on my PC and Night Shift on my iPhone, but I use my iPad the most in bed and it's old enough that it doesn't have a Night Shift. How do I make it do the orange light thing?

  • z9elka
    z9elka 3 months ago

    poor rats :(

  • Riste dzisev
    Riste dzisev 3 months ago

    Man youre crazy i sleep with lights on and my phone on a youtube playlist the whole night with 2 pillows and a giant blanket over my head. Its pretty comfortable and i would much rather have that than pitch black and quiet and listen to my ears rinning and think the monster from russian sleep experiment or the devil with no eyes and blood is staring at me waitting for me to move and shit my pants jesusCHRIST

  • Krishna Vma
    Krishna Vma 3 months ago

    Thank you for this. All my life I've been a chronic sleep avoider, seeing it as wasted time. My loved ones will be happy to hear that you have managed to convince me that sleep really is necessary and mandatory. Cheers! 🙂

  • Amazing Deep House
    Amazing Deep House 3 months ago

    the poor rats

  • lamp 81
    lamp 81 3 months ago

    I really had no idea that fibromyalgia was worsened by lack of sleep. It really does correspond to my pain levels when I cannot sleep and I cannot do much the next day due to pain and fuzzy brain and lack of motivation. This pain builds up if I do exercise during a bad a day and then keeps me awake the next night because I cannot find a comfortable position. So...if I can somehow sleep then I can feel better and break the cycle! Thanks for the info! I am going to have to stop looking at my phone in bed and just listen to audible or white noise and maybe magazines, catalogues or crossword puzzles, even though that means I leave a light while I am fall asleep. Ok, giving this a try. Amazing!

  • Out Of Place Ninja
    Out Of Place Ninja 3 months ago

    Wait, number six, there was somebody who purposely burned mice, then purposely deprived them of sleep for the purpose of "study"? Sounds like some areas of science is where the crazy people hide to stay out of trouble with society and the law lol.

  • Lin He
    Lin He 3 months ago

    Here I am, watching a YouTube video on my iPad right before bed time.

  • Sierra Miranda
    Sierra Miranda 3 months ago

    Don't we sleep because we're tired of doing shit all day???? I thought it as common sense

  • kidego3kgt
    kidego3kgt 3 months ago

    All those dead rats. RIP.

  • Bill Hampton
    Bill Hampton 3 months ago

    Anybody ever tried meth ? Holy fuck! , 80 hours without one wink of sleep . That shit is crazy I don't how people can keep doing that stuff .

  • IAmAgainst
    IAmAgainst 3 months ago

    Am I the only one thinking in the miserable life the rats in those studies had..?

  • Big Daddy Jam Dawg
    Big Daddy Jam Dawg 3 months ago

    where did you get your shirt?

  • Elena Sucec
    Elena Sucec 3 months ago

    Poor Rats they take so much @&$% so we don't have to. They definitely got the short end of the stick

  • Elena Sucec
    Elena Sucec 3 months ago

    Who else is procrastinateing sleep staying up late watching YouTube videos!

  • Eduardo Paulo
    Eduardo Paulo 3 months ago


  • EatenRibs i-si-u
    EatenRibs i-si-u 3 months ago

    " still running in the family* but they keep reproducing, such genes to protect ...

  • Jim McBride
    Jim McBride 3 months ago

    "Sleeplessness makes pain worse." Seems reason enough for getting sleep, fwiw

  • Dennis Jasperse
    Dennis Jasperse 3 months ago

    So how do you explain most of the time set the alarm clock and most of the time you wake up maybe 5 minutes early!!!!

  • Doug sillig
    Doug sillig 3 months ago +1

    is it just me or is Hank's voice a little raspy?

  • Notlehs Bulb
    Notlehs Bulb 3 months ago

    Anyone else watching at 3am?

  • Michael Carter
    Michael Carter 3 months ago

    Why are you fidgeting and using hand gestures so much? It's random; like your just fidgeting just to fidget. Plus it's annoying. until you can tone it down, in unsubscribing.

  • Mikael Durbin
    Mikael Durbin 3 months ago

    My wife and two children have FFI. This mutation is trying to take everything I love. Is there any breakthroughs anywhere? Vanderbilt didn't have a clue what we were even talking about. The dr didn't even take the time to google it

  • spartanace13
    spartanace13 3 months ago

    8:05 Wrong kind of cat video, guess again.

  • Mathy Don
    Mathy Don 3 months ago

    Aw those poor rats, what a way to die. Sleep deprived to death...

  • Wolfpack Q
    Wolfpack Q 3 months ago

    I could use some sleep

  • pete1
    pete1 3 months ago

    If you take one thing from that video it should be: don't get reincarnated as a rat!

  • Ni Enye
    Ni Enye 3 months ago

    eeg isn't a new technique at all. wait.... how did I get here. I need to sleep.

  • Dreterria Maiden
    Dreterria Maiden 3 months ago +1

    So....we're Rats now ?😂

  • Clarinet Catato
    Clarinet Catato 3 months ago

    Here's what I think are the two most important facts about sleep: The fact that sleep is necessary and how much you should get

  • BvsMAcosh
    BvsMAcosh 3 months ago

    none of this is groundbreaking. Or even new.

  • actsrv9
    actsrv9 3 months ago

    poor lab rats

  • Vio
    Vio 3 months ago

    i have such a shit sleep schedule/cycle i know my brain & body are getting rekt.

  • Lester Stumpf
    Lester Stumpf 3 months ago

    am i the only one who is glad to not be a rat?

  • Graxster
    Graxster 3 months ago

    I guess it's a good thing that I go to sleep every night. Oh wait... I wasn't even worried about it. :D

  • apcolleen
    apcolleen 3 months ago

    what did people blame insomnia on before electricity?

  • Praise Pepe, God of Kek

    Well, that are happy rats

  • edward Andrews
    edward Andrews 3 months ago

    i only sleep for a hour and a half, been this way all my life, ive never had any side affects, i always feel rested and alert, and i even dream, drove my parents nuts when i was a child

  • bnighter
    bnighter 3 months ago

    so my kindle is killing me. softly.

  • icedragonxl4
    icedragonxl4 3 months ago

    There were some incorrect facts in this video that I hope it's okay for me to correct. In the first discovery that says that sleep can kill you is incorrect. The truth is we don't quite actually know if that's the case yet or at all. Yes mice die after a couple of weeks with no sleep but the symptoms that cause them to die don't seem to show in humans I believe; and yes, fatal familial insomnia is deadly and kills those afflicted with it, but again, we don't know if it's the lack of sleep that causes the death or the other symptoms of the disorder. Also, the date in #3 was incorrect as well. The activity of the brain during sleep wasn't discovered until the 1950s at the University of Chicago using electroencephalogram.

  • Ron Josh Ytem
    Ron Josh Ytem 3 months ago

    I wonder if the memory test was affected by the intermittent information gathered while the subjects stayed awake.

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