Why We Sleep: Unlocking the Power of Sleep and Dreams review

Why We Sleep: Unlocking the Power of Sleep and Dreams

Why We Sleep: Unlocking the Power of Sleep and Dreams by Matthew Walker

My rating: 5 of 5 stars

I’m not sure why I decided to read this book about sleep at a time in my life when I’m fairly sleep-deprived (hi Baby Nick!), although it’s not as bad as when I read a book about airplane crashes while on an airplane. (for the record: I was OK reading the book, but watching the airplane scene of the movie Flight creeped me the heck out!)

Anyway, this is a really really good book that everyone should read. I’ve always been mildly interested in sleep, so I knew some of this stuff, but there was a ton of stuff I didn’t know and a lot of it was very interesting. The book is full of interesting studies that sound like they were pretty well done.

The upshot of the book is: sleep is really important and does a ton of stuff for your body, and getting less than you should impacts you in a ton of ways. Basically everyone needs between seven and nine hours a night. So prioritize sleep!

Now for the details I found particularly interesting:
– There are two main stages of sleep: REM (rapid eye movement) and NREM (non-REM). I knew this but I could never remember which is the important one, and the reason is that they’re both important! NREM is important for memory retention (moving short-term memories into longer-term storage), and REM sleep is important for “recharging” your ability to handle your own emotions and detect emotions in others.
– The easy way to tell whether you’re getting enough sleep is to answer these questions: after waking up in the morning, could you go back to sleep at 10 or 11 AM? And can you function without caffeine before noon? If the answers are “yes” or “no” respectively, you’re probably at least somewhat sleep deprived.
– Animals vary wildly in how much they sleep, even among similar species, and we don’t know why. (opossums sleep 50% longer than rats!) Also, fur seals have both NREM and REM sleep when they’re on land, but when in the water they stop having REM sleep, as far as we can tell.
– I had read that in the old days, people would sleep in two chunks, and in between they’d be awake for several hours. This is true, but it wasn’t nearly as universal as I had thought – it seems to have been just a Western European practice for a little while around the year 1700.
– Lack of REM sleep makes it harder to regulate your emotions (to which I said “hahahaha sob I know!”)
– Asking a teenager to wake up at 7 AM is like asking an adult to wake up at 4 or 5 AM, and high schools really really should start later in the morning than they do. (some high schools have moved back their start time to closer to 9 AM, which is great!)
– As we get older, we get less and less quality sleep, and this is responsible for some of the effects of old age, both physical and mental. People think that seniors need less sleep, but that’s only because it’s hard to tell how much quality sleep you’re getting – all evidence shows that seniors need as much quality sleep as other adults.
– NREM sleep is more concentrated near the beginning of your sleep period, while REM sleep is more concentrated near the end. So if you go to bed later than usual, you’re missing out on mostly NREM sleep, and if you wake up early, you’re missing out on mostly REM sleep.
– There’s an experimental protocol that stimulates the brain during NREM sleep that almost doubles the facts that people were able to remember the next day! They’ve also shown a lesser effect (around 40% improvement) just by emitting sounds in sync with brain waves, and even rocking the bed in sync with brain waves seems to improve NREM sleep.
– In a test of reaction time, people who got six hours of sleep per night for ten nights did as badly as people who had been awake for twenty-four hours!
– This link hasn’t been proven yet, but studies suggest that lack of NREM sleep may raise your risk for Alzheimer’s. Yikes!
– Switching to daylight saving time (i.e. losing an hour) leads to a spike in heart attacks the next day. Conversely, switching away from daylight saving time leads to a big drop in heart attacks. The same effect can be seen in traffic accidents.
– People who had gotten more sleep were rated as looking more healthy and more attractive 🙂
– There are only epidemiological studies (i.e. not double-blind and well-controlled), but there’s some evidence that nighttime shift work and the disrupting of circadian rhythms increase your odds of getting various cancers. Denmark has actually started to pay worker’s compensation to people who developed cancer after working night-shift work in government jobs.
– To get over emotional trauma, dreaming about the painful experience (which can be done with little emotion) seems to be necessary to get past it. PTSD seems to be a breakdown in the ability to do this – the brain keeps trying to dream about the painful event but it always has the strong emotions associated with it.
– Going without REM sleep impairs your ability to detect emotions in others – you tend to see the world as a more threatening place. (i.e. you become more paranoid) This is not a great thing for people who have night shift work, like nurses, doctors, and police officers!
– Waking people up in the middle of REM sleep makes them way more creative! (as measured by a test to find anagrams) And dreaming about a particular task does seem to make you much more able to find creative solutions to that task.
– I’ve read this before, but it still surprises me – the optimal sleeping temperature is around 65 degrees, which is cold!
– It seems like many children that have been diagnosed with ADHD may just be sleep-deprived. (obviously it’s hard to determine this on a large scale, but the symptoms are pretty similar, and the author’s estimate is that more than half of kids with ADHD fall into this bucket!)
– The big insurance company Aetna gives bonuses to their employees who wear sleep trackers and regularly get seven hours of sleep per night. (I applaud their efforts, but this is creepy)
– I understand narcolepsy a bit better now (the “sleep-wake” switch in the brain is unstable and easily gets triggered), and it sounds really hard to live with, especially since the treatment options we have today are not very good 😦

Anyway, I highly recommend this book, and if you want to try to sleep better here are some tips from the National Sleep Foundation, although there’s nothing earth-shattering there. I was planning on giving this book four stars because the laundry list of “things lack of sleep makes worse” got a little long (the book is on the long side at 360 pages), but the book was so interesting in general I had to give it five!

As I mentioned earlier, I’m trying to avoid buying from Amazon, so this was the first book I read on the Barnes & Noble Nook app. And it was totally fine and a perfectly reasonable substitute for Kindle!

View all my reviews

3 thoughts on “Why We Sleep: Unlocking the Power of Sleep and Dreams review”

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