Why We Sleep - Unlocking the Power of Sleep and Dreams

Overview

• Author: Matthew Walker

Notes

• two main factors determine when you want to sleep and be awake
  • circadian rytm
    • internal clock located deep in brain
    • clock create day-night rythm
    • melatonin increases when it’s time to sleep
  • Adenosine: Sleep pressure
    • chemical substance that builds up in your brain and creates sleep pressure the longer you’ve been awake
    • Hence, you feel sleepier
• two types of sleep
  • REM: Rapid Eye Movement
  • NREM: Non REM
• We cycle through these two types of sleep
  • sleep stages *
• REM
  • memories replayed slowly - half 1/4 the speed
  • Best explanation for deaccelation in time
  • our muscles are paralyzed
• Memory
  • The last two hours of sleep are the richest spindle bursts of brainwave activity - don’t miss out on those!
  • The more good nights of sleep, the better the memories
• Benefits of sleep
  • Memory
  • life extension
  • stress levels
  • Sleep is the third pillar of good health(eat, exercise, sleep)
  • cardiovascular
• as we approach midlife, our body begins to deteriorate and health resilience declines.
  • adules 45 and over who sleep fewer than 6hrs, are 200% more likely to have a heart attack
• the less you sleep, the more you are likely to eat
• sleepting less than 7 hrs will increase yoru probability of gaining weight → type 2 diabetes

dreaming

• Dreaming in REM sleep
• Deep NREM sleep strengthens individual memories
• REM sleep creates masterful connections with thos memories
• During REM sleep all voluntary muscles are pralyzed. Dreamer can’t act out. Only muscles that move are eye muscles
• Events happen in deep NREM sleep rather than REM sleep
• we don’t understand the cause of somnambulism episodes. Evidence suggest this is due to unexpected spies in nevous system activity during NREM. This electrical jol comples the brain to rocket from deep NREM to wakefulness
  • Trapped in these two worlds of deep sleep and wakefulness, the brain performs basic but well-rehearsed actions (walking, closet, bahtroom, etc)
• There’s nothing pathological about sleepwalking or sleep talking- common in adult population

Other

• Insomnia is one of the most pressing and prevalen t medical issues facing modern society.
• sleep “aid” industry is worth 30 bn US
  • desperate millinos are willing to pay to get a “good night sleep”
• most common triggers of chronic insomnia
  • emotial concerns/worry
  • emotional distress or anxiety

What can you do to get a better nigh sleep?

1. Stick to a sleep schedule
   1. night, morning, weekends
2. Exercise but not too late in the day
3. Avoid caffeine and nicotine
4. Avoid alcoholic drinks before bed
5. Avoid large meals or beverages
6. Avoid medicines that delay sleep
7. Don’t take naps after 3pm
8. Relax before bed
9. Take a hot bath before bed
   1. Drop in body temperature after a hot bath helps
10. Dark/cool room
    1. get rid of anything that may distract you (noises, lights, unconfortable bed, tv, cellphone, etc)
11. Have the right sunlight exposure
    1. daylight is key to regulating sleep patterns
12. Don’t lie in bed awake