When I was in college, I was encouraged to read and to read broadly. I have tried to follow that advice. “Readers are leaders,” goes one saying. Most of the people who have influenced me and whom I respect the most have been readers, so maybe there is something to that. The reviews on this site are for books that I have personally read, were a help to me, and I recommend (sometimes with caveats) to you. I hope they will encourage you to start reading (if you don’t tend to) or read more and more broadly (if you already do).
- Author: Matthew Walker, PhD (Director of UC Berkeley’s Sleep and Neuroimaging Lab)
- 342 pages
- First Edition (Hardcover), 2017
- Amazon, Thriftbooks, Alibris
Dr. Walker begins the book by addressing our culture’s penchant for sleep deprivation and the health consequences for it.
“Two-thirds of adults throughout all developed nations fail to obtain the recommended eight hours of nightly sleep… the shorter your sleep, the shorter your lifespan.”Walker, Why We Sleep, pp. 3-4.
Yikes. The book is divided into four parts.
Part One deals with the sleep itself: how does the body initiate sleep (circadian rhythm; melatonin; adenosine; etc.); what is happening in our brains and to our bodies while we sleep (NREM; REM; etc.); how does sleep differ among other creatures; and how sleep changes over our lifespans (in utero – old age). Readers will be encouraged to find out that there are genetic and physiological justifications for claiming “I am a morning person,” or “I am a night owl.” And, no, you cannot change that.
One fascinating tidbit on the animal kingdom:
“[Cetaceans’, such as dolphins and whales,] sleep… can be unihemispheric, meaning they will sleep with half a brain at a time! One half of the brain must always stay awake to maintain life-necessary movement in the aquatic environment.”Walker, p. 64.
Part Two address the question “Why Should You Sleep?” The benefits of enough sleep (Walker seems to hint that a 7.5 – 9 hour window of sleep opportunity is most beneficial), the consequences of sleep deprivation, and the connections of sleep loss to some of the most dangerous health conditions, including diabetes, heart attacks, and cancer.
In Chapter 7, Walker references a study on sleep deprivation and its effects on concentration. Subjects were tested on their ability to push a button and the sound of a beep. To control, everyone did this exercise after a sufficient night’s sleep. Subjects were then separated into three groups of varying sleep-times per night. One group went 72 hours with no sleep.
“After the first night of no sleep at all, their lapses in concentration (missed responses) increased by over 400 percent!”Walker, p. 136.
These lapses are referred to as “microsleeps:” moments when you fail to respond to external stimuli even though you are (technically) supposed to be awake. More frightening than the one night of entirely missed sleep, is the results of repeated nights of low sleep.
“Ten days of six hours of sleep a night was all it took to become as impaired in performance as going without sleep for twenty-four hours straight.”Walker, p. 136.
How familiar is the six-hour night’s sleep to some of us?
Part Three is about dreams and dreaming, and Part Four moves to the very practical topics of what is keeping us from getting enough sleep (from modern technology to sleep disorders) and how we can remedy that. (One hint: Put your computers, tablets, and cell phones away a good while before you want to go to bed.)
“Artificial light in modern societies… tricks us into believing night is still day… [and] winds back your internal twenty-four-hour clock… usually two to three hours each evening, on average.”Walker, p. 267.
Dr. Matthew Walker’s book is a thorough and detailed look at the physiology and benefits of sleep and dreaming. It is meticulously supported by research and studies, some of which are fascinating to read in and of themselves. Through his research and practical explanations, Walker challenges us to allow one naturally-occurring activity of our lives (i.e., sleep) to have its beneficial effect. In our technologically modern society, this will take forethought. But Dr. Walker doesn’t leave us to our own devices. The book is full of practical suggestions for how to get a good night’s sleep, followed by the Appendix, “Twelve Tips for Healthy Sleep.”
Christian readers can overlook Dr. Walker’s evolutionary explanations, and see instead the goodness and greatness of the Creator.