The Joe Rogan Experience – Sleep Expert and Neuroscientist Dr. Matthew Walker


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Sleeping in Foreign Environments

  • One half of your brain won’t sleep as deeply as the other, when sleeping in a foreign environment, like a hotel room
  • There are two types of sleep
    • REM Sleep
    • Non-REM Sleep (of which there are 4 stages, stages 1-4)
      • In stages 3 and 4, that’s where a lot of body replenishment takes place
        • These are the stages of sleep that one half of your brain will resist going into when you’re sleeping in a foreign environment

sleep and drugs

  • Joe has noticed after he stopped smoking cannabis for a short period of time, he had very vivid dreams
  • Cannabis is very good at blocking  REM (dream sleep) – alcohol also blocks REM sleep.
    • The brain is very clever, and builds up a clock count of how much dream sleep you should of had, but have not been getting
    • The brain develops such an appetite for dream sleep, that you’ll get a REM sleep rebound effect if you stop smoking for a period of time
      • This is where you have really intense dreams
  • Marijuana certainly puts people to sleep quicker, but its debatable whether it’s naturalistic sleep
  • When an alcoholic stops drinking alcohol, they’ll often develop delirium tremens
    • The alcohol has been blocking REM sleep so long, and the pressure for deep sleep has built up so much, it has spilled over into wakefulness. You essentially dream while you’re awake.


  • When we dream, we essentially become psychotic – we see things that aren’t there (hallucination), we believe things that couldn’t possibly be true (delusion), we have wildly fluctuating emotions, and we become confused about time/place
  • In REM sleep, some parts of the brain become 30% more active compared to when awake
    • Parts of the brain regulating emotion ramp up, same with visual and motor parts of the brain
    • However, the prefrontal cortex (associated with rational thinking) gets shut off
      • So really, in dreams, there’s no “controller” or “driver”
  • Why do we forget dreams?
    • One theory of dreaming, is that it’s a reconstruction of fragments, and our cortex packages everything together and makes a good story – Matthew doesn’t really agree with this
    • Not remembering dreams doesn’t necessarily mean forgetting your dreams
      • Often times, random things trigger the unlocking of a dream memory
      • The memory of the dream is available, but when we wake up, we lose the “IP address” of that memory – it’s available, just not accessible
        • Our dream memories, whether we know of them or not, can have non-conscious impacts on our behavior all the time
        • It’s really possible that we store every one of our dreams
    • In the brain, during REM sleep, the chemistry of the brain is very different
      • Noradrenaline (a stress chemical), the sister chemical of adrenaline, plummets to very low levels
      • When you wake up, that’s when you have the spike of noradrenaline
      • Another chemical, acetylcholine, goes up in REM sleep
      • This specific balance of noradrenaline and acetylcholine change the input/output of information flow into the memory center of the brain
        • It’s more about output (generating dreams), than input (the saving of memories/dreams)
        • This is very similar to a DMT trip – shortly afterwards it feels like a dream
  • Why do we dream? Why did it evolve evolutionary?
    • Perhaps it’s just a byproduct of REM sleep
      • Matthew doesn’t agree with this because it’s metabolically demanding to have dreams in addition to REM sleep, and whenever mother nature burn calories it’s usually for a reason

stages of sleep

  • ALL stages of sleep are important
    • “Mother nature wouldn’t waste time putting you into a state that wasn’t necessary”
  • What happens during REM sleep?
    • Our cardiovascular system goes through periods of dramatic acceleration and then dramatic deceleration
    • Our brain paralyzes our body so our mind can dream safely
      • So we don’t dream we can fly, and then attempt to do this
    • Our brain replays memory sequences we learn while awake, but ~20x faster than when you’re awake
      • “Practice doesn’t make perfect. Practice with a night of sleep makes perfect.”
      • You come back the next day and you’re 20-30 times better at your skilled performance, compared to the end of your practice session the day before
      • “Sleep is the greatest legal performance enhancing drug that most people are probably neglecting”
    • Sleep doesn’t improve the places where we’re already good in terms of motor skills, sleep is intelligent – it finds friction points or motor skill deficits, and smooths them out/improves them
      • This is very common with musicians – one day they aren’t able to nail a piece, and the next day they can
    • During dream sleep, we take old information, and combine it with new information we’ve learned, and form new connections/associations
      • For this reason, we might often find new solutions to previously unsolvable problems after a good sleep
      • Thomas Edison used sleep as a vital tool for creativity

The horrible effects cause by a lack of sleep – Part 1

  • Lack of sleep and physical performance
    • If you’re getting 6 hours of sleep or less, your time to physical exhaustion drops by up to 30%
    • Lactic acid builds up quicker the less you sleep
    • The ability of your lungs to expire CO2 and inhale oxygen decreases
    • The less sleep you have
      • The lower your peak muscular strength, lower your vertical jump height, and lower your peak running speed
    • A higher injury risk
      • One study showed a 60% increase in probability of injury comparing people who get 9 hours of sleep a night, to those who get 5
      • Your stability muscles fail earlier when not getting enough sleep
  • We need 7-9 hours a night
    • Once you get below 7, we can measure impairments in the brain 
    • There is a small fraction of <1% of the population, that has a certain gene that allows them to survive on 5 hours of sleep
      • You are more likely to be struck by lighting than have this gene
      • The gene promotes wakefulness chemistry in the brain

light and sleep

  • “We are a dark deprived society in this modern era” – this lack of darkness is destroying out quality of sleep
  • Incandescent light bulbs suppress melatonin
    • Screen usage on top, suppresses it even further
      • One hour of Iphone use will delay the onset of melatonin production by about 3 hours
        • Your peak melatonin levels will also be 50% less
      • All of this adds up to less REM sleep

What should a person do if they have a hard time falling or staying asleep?

  • Regularity is most important – go to bed, and wake up at the same time every day
  • The last hour of the day, stay away from any screens
    • Turn off most of the lights in your house at night 2-3 hours before bed
  • Keep your room cool
    • Your brain needs to drop its temperature 2-3 °F in order to sleep
    • Check out the Chillipad – this works as well
    • Studies show sleeping somewhat naked can help to
    • Warm your hands and your feet to move the blood away from your core out to the surface
      • Matthew recommends either going to sleep with socks and gloves on, or taking a warm bath right before bed
      • With a warm bath, you get vasodilation (rosy cheeks, red skin) and all of the blood rushes to the surface – when you get out, you have a massive dump of heat from the body, and the core body temp. plummets  
  • Sleep and Diet
    • “Don’t go to bed too full, and don’t go to bed too hungry”
    • Diets high in sugar and low in fiber tend not to be good for sleep – results in less deep sleep and your sleep ends up being more fragmented
  • Supplements
    • Melatonin is useful when traveling between time zones – it fools your brain into thinking it’s time to go to bed
      • Once you’re stable in a new time zone, melatonin doesn’t seem to be advantageous towards sleep – it’s much more of a placebo effect
      • However, if you’re taking it, and think it works – it won’t hurt, keep taking it
      • As we age, our circadian rythm starts to get blunted – this is where nightly use of melatonin has been shown to be beneficial

sleep and evolution

  • Hunter gather tribes tended to go to sleep 2 hours after dusk when the climate temperature started to drop
    • They also got up about 30 or so minutes before dawn – due to the rise in temperature
    • Midnight should actually be the middle of the night, and now midnight has become the time where we check Facebook
  • Maybe we should be sleeping biphasically?
    • People think the post-prandial dip (around 2-4pm) is dependent on diet, but it’s not true according to Dr. Walker
      • Even people who abstain from lunch will have a drop in physiological alertness during this period
      • “It’s a genetically hardwired preprogrammed drop that suggests we should be sleeping biphassically”
      • The lull exists no matter what, even if you don’t think it happens to you

The horrible effects caused by a lack of sleep – Part 2

  • The shorter your sleep on average, the shorter your life
    • Short sleep predicts all cause mortality
  • Wakefulness, compared to sleep, is low level brain damage. Sleep offers a repair mechanism for this.
    • During deep sleep at night, there is a sewage system in the brain that cleanses the brain of all the metabolic toxins that have accumulated throughout the day
      • One of those toxins is beta amyloid – which is responsible for the underlying mechahism of Alzheimer’s disease
      • The less you sleep – the more this plaque builds up
      • Insufficient sleeps is the most significant lifestyle factor for determining whether or not you’ll develop Alzheimer’s Disease
  • Insufficient sleep is linked to bowl, prostate, and breast cancer
    • The WHO has decided to classify any form of nighttime shift work as a probable carcinogen
    • Shift workers have higher rates obesity, diabetes, and cancer
  • Leptin and ghrelin
    • Both control appetite and weight
    • Leptin tells our brain we’re full
    • Ghrelin does the opposite, it’s the hunger hormone
    • With less sleep, leptin gets suppressed, and ghrelin gets ramped up
      • People sleeping 4-5 hours a night will on average eat 200-300 extra calories each day (70,000 extra calories each year which translates into 10-15 lbs. of body mass)
      • You also eat more of the wrong things
    • Lack of sleep if a critical factor of the obesity epidemic
  • 1 out of every 2 adults in America are not getting the recommended 8 hours of sleep
    • 1 out of 3 people are trying to survive on 6 hours or less of sleep
    • The average American adult is sleeping 6 hours and 31 minutes during the week (it used to be 7.9 hours in 1942)
    • “The number of people who can survive on 6 hours of sleep or less, rounded to a whole number, and expressed as a percentage of the population is 0”
    • “You don’t know you’re sleep deprived, when you’re sleep deprived”
  • Under slept employees will take on fewer work challenges, are more likely to slack off in groups, and are less likely to come up with creative solutions
  • Less sleep does not equal more productivity


  • We can’t use naps to regain sleep we’ve lost
  • “Sleep is not like a bank. We can’t accumulate a debt and hope to pay it off on the weekend”
    • Dr. Walker estimates that if you pull an all nighter, and then are allowed to sleep as long as you want the next night, you’ll sleep longer but you’ll only get back 3-4 hours of that lost total 8
    • Being able to store sleep would be useful evolutionary – just like we can store fat for times of famine
      • Why can’t we do this? – Humans beings are the only species that deprive themselves of sleep for no apparent reason. Mother nature has never faced the challenge of coming up with a safety net for lack of sleep
      • Lack of sleep is a recent occurrence – we can only force a species to sleep less when we starve them
        • This is why when fasting (for 2-3 days), people have bad sleep – it only makes you more hungry
        • When you’re starved – ghrelin levels are high, and this also boosts dopamine which keep you awake
        • However – we don’t know how going into ketosis effects this. By starved, we mean really starved. If you’re in ketosis, perhaps you’ll sleep fine.

The horrible effects cause by a lack of sleep – Part 3

  • Men who sleep 5-6 hours a night will have a level of testosterone 6-10 years their senior
  • With 14 days straight of 6 hours sleep or less, your cognitive performance nose dives, and with no sign of leveling off
  • After 20 hours of being awake, you are as physically and cognitively impaired as you would be if you were legally drunk
  • Every 30 seconds, there is a car accident linked to lack of sleep
    • Drowsy driving kills more people on the roads than alcohol or drugs combined
    • When you’re under slept, we have micro sleeps – the eyelid partially closes, but the brain goes to sleep for a brief period of time
      • Effectively, this means you have a 2 ton missile traveling at 65 mph with no one in control
  • Perhaps we should have later school start times for teenagers
    • One study documented a school which shifted school start times from 7:35am to 8:55am – this resulted in 70% reduction in car crashes the following year
      • For comparison – anti lock breaks dropped accident rates 20%
    • “If the goal is to keep our kids safe, and to get them well educated, early school start times are not the thing to do”
    • One school shifted start times from 7:25am to 8:30am, average SAT scores rose 212 points
  • The prefrontal coretx is the first thing to switch off when we’re lacking in sleep – the emotional centers of the brain, which are controlled by the coretx, are also effected
  • One study sleep deprived individuals for one night (to 4 hours of sleep) – they experienced a 70% reduction in critical anti cancer fighting cells (natural killer cells)
    • We all have cancer cells within our body, and what really prevents the formation of full on cancer, are these natural killer cells
  • Daylight savings time
    • In the spring, when we lose an hour of sleep, we see a 24% increase in heart attacks
    • In the fall, when we gain an hour of sleep, there’s a 21% decrease in heart attacks
  • One study found that, with one week of 6 hours of sleep per night, 711 genes were distorted in their activity
    • Half of those genes experienced an increase in activity – these were genes related to the promotion of tumors, genes related to chronic inflammation, and genes associated with stress (and therefore cardiovascular disease)
    • Half of these genes were suppressed – many of these were genes related to immune response, so we become immune deficient with a lack of sleep
  • Many of the children diagnosed with ADHD are just under slept
  • A lack of sleep costs most nations about 2% of their GDP
    • In America – that’s $411 billion
    • Solve the sleep epidemic and you could double the budget for education and half the budget for healthcare
  • If you’re dieting, but not getting sufficient sleep, 70% of all the weight you lose will come from lean muscle, not fat – our body becomes resistant at giving up fat when it’s underslept
  • Supplements to deal with a lack of sleep
    • Caffeine can help you get over the basic reduction in alertness and can moderately improve response times
    • Modafinil – Works through the dopamine pathway (the pleasure pathway) – it raises dopamine to increase alertness

Sleep and Medicine

  • Most doctors only have about 2 hours of sleep education in their medical curriculum
  • Residents working a 30 hours shift are 460% more likely to make diagnostic errors in the intensive care unit, relative to when they’re working 16 hours
  • If you have surgery, you should ask your surgeon how much sleep they’ve had in the last 24 hours
    • If they’ve had 6 hours of sleep or less – you have a 170% increased risk of a major surgical error
  • 1 in 5 medical residents will make an error due to insufficient sleep, 1 in 20 medical residents will kill a patient due to a fatigue related error
  • “The one place where you need a good night of sleep the most, in the hospital, is the one place you can’t get it”
    • Why don’t we get ear plugs and an eye mask, like we do when we fly, in the hospital?

to sum up

  • “Sleep is the elixir of life. It is the most widely available and democratic powerful healthcare system I could ever possibly imagine.”

Joe Rogan Experience : ,
Notes By MMiller

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