Dr. Matthew Walker
0:30 - Sleeping in unfamiliar environments often induces a deep sleep resistance. This is a type of threat detection and is the reason we sometimes feel tired even after sleeping for long periods while on vacation, or while travelling.
4:40 - With alcohol - and possibly marijuana - the brain' s clock counter of dream sleep builds up, and when the liver and kidneys eventually flush out the alcohol in the system - approximately 6 hours after finishing drinking - you get a REM sleep rebound effect characterized by brief but intense or vivid dreams. The flood gates re-open so to speak.
6:50 - Coming off severe alcohol addiction you can experience Delirium Tremens (DT). Here the pressure for dream sleep is so high that it spills over into wakefulness. You essentially start to dream while you're awake; think physical withdrawal symptoms & deliriousness.
9:00 - Testosterone in men who suffer from a lack of sleep. It ages you by a decade and places your T levels at that of someone 10 years your senior.
12:00 - The flagrant psychosis of sleep itself. You see things that aren't there, you believe things that can't be true, and when you wake up, you immediately forget everything that happened.
14:00 - During sleep the C.E.O. of the brain shuts down - the prison guards of rationality (pre-frontal cortex) are gone and the rest of the brain runs amok.
17:00 - Dreams are often available to memory, but not accessible. In a sense, we lose the IP address.
23:50 - It's possible that dreaming is just the heat of REM sleep. The purpose of a light bulb is to produce light, and heat is just a by-product, though it's unlikely that evolution would devote essential metabolic energy to something that was unnecessary.
28:40 - Cardiovascular system goes through rapid acceleration and deceleration during REM sleep. The brain locks you down in sleep paralysis so you can dream safely. This is a kind of muscular incarceration so that you don't act out your dreams physically, as this would be dangerous evolutionarily.
32:30 - Practice doesn't make perfect. Practice with a night of sleep makes perfect. Skill performance increases by 20% - 30% of where you were at the end of your last practice the day before if you get a full night of sleep. Sleep improves automaticity an fluidity of skill performance.
33:10 - 6 hours of sleep or less and time to physical exhaustion drops by 30%. Lactic acid builds up quicker, lungs can't expire CO 2 or inhale O 2 as efficiently. Muscle strength goes down. This is the feeling of being de-trained.
36:50 - There is a perfect linear relationship between athletes sleep levels - or lack thereof - and risk for injury.
39:20 - Simply visualizing passive play can cause a rewiring of the brain beneficially.
42:35 - Sleep is so intelligent that it actually finds problem points - deficits in motors skills and performance - and smooths them out to create fluidity.
50:30 - Five sleep strategies: 1) Regularity, wake and sleep at the same time every night. 2) No light 1 hr before bed. 3) Keep cool, core temperature needs to decrease 2-3 degrees Fahrenheit for optimal sleep conditions. Hot shower or bath can help lower core temperature to achieve this. 4) Eat a few hours before bed, no sugar, some fiber. 5) Melatonin is for the elderly or time-zone changes only, otherwise it's likely a placebo.
54:55 - We may be designed to sleep bi-phasically. Hunter gatherers didn't sleep for one long eight hour period. In the summer months, they would practice a siesta like behavior due to mid-day postprandial dip in alertness. This dip exists independently of dietary composition.
58:15 - The shorter your sleep, the shorter your life. Lack of sleep increases all cause mortality. Wakefulness is actually low level brain damage, and sleep offers the reparative function. Insufficient sleep over a lifetime is a leading factor in the development of Alzheimer's.
1:02:00 - Lack of sleep has a strong obesogenic profile because not only do people eat more late at night, but they eat the wrong things.
1:04:35 - There is no credit system for sleep in the brain. You can't bank it. If 8 hrs of sleep is lost, the absolute best you can do is repay 3-4 hours of that over several days if conditions are then perfect.
1:05:30 - Human are the only species that deliberately deprive themselves of sleep for no apparent reason. In other words, mother nature has never faced the challenge of coming up with a safety net for a lack of sleep. That's why we get such demonstrable disease and sickness when we undergo a lack of sleep.
1:07:00 - 1:14:15 - Pitfalls of extended fasting. Drowsy driving is worse than impaired driving.
1:20:35 - Almost 50% of adults are chronically sleep deprived. The number of people who can survive on 6 hours or less of sleep without showing any impairment rounded to a whole number and expressed as a percentage of the population is zero (0%).
1:26:10 - The pre-frontal cortex - the rational part of the brain - is the first to get switched off with sleep deprivation.
1:27:30 - After 1 night of 4 hours of sleep, you experience a 70% decrease in natural killer cells (these ward off cancer). During daylight savings time we lose 1 hour of sleep. This equals a 24% increase in heart attacks. In the fall, we gain an hour of sleep. This equals a 21% decrease in heart attacks.
1:34:40 - During sleep at night the sewage system in the brain kicks into high gear and cleanses the brain of metabolic toxins built up during the day. These are largely beta-amyloid plaques (Alzheimer's)
1:40:50 - Junior residents working a 30 hour shift are 460% more likely to make a diagnostic error in the I.C.U. relative to a 16 hour shift. If your surgeon has less than 6 hours of sleep, you have a 170% increase risk of a major surgical error, such as hemorrhage or organ damage.
1:45:20 - 1 in 20 medical residents will kill a patient due to a fatigue related error.
1:47:50 - 50% of all I.C.U. alarms are unnecessary. Turns the lights off in the neonatal I.C.U. and infant O2 saturation goes up, weight gain goes up, and the exit the unit 5 weeks earlier.
1:52:00 - If you're dieting but no sleeping, 70% of the weight you lose will come from L.B.M. Lack of sleep costs most nations about 2% of GDP per year. In the U.S. that's about $411 billion.