Why We Sleep – Unlocking the Power of Sleep and Dreams
By Matthew Walker, Simon & Schuster, 2017
In Tom Clancy’s counter-terrorism thriller, “Rainbow Six,” our hero John Clark says, “Rest is a weapon.” That phrase stuck with me.
Until this month, I did not realize how impactful sleep is upon our physical, mental and spiritual health. Matthew Walker, professor of neuroscience, in his book “Why We Sleep” helps us to understand the marvelous mystery of what happens when we close our eyes and drift off into dreamland.
Our journey begins with a basic description of how sleep happens. Each of us has a particular relationship with our sleeping habits. Some of us are naturally inclined to head up to bed early in the evening and then arise before the sun comes up. Others are in their element later in the day and do their best work late at night. In that case, getting up early may not work for them.
Matt Walker points out there is a natural distribution of morning larks and night owls. Society has evolved to favor the early risers. We might even tend to think those who get up late are lazy. This is unfortunate for we do not choose our sleep preference any more than we choose to be left-handed or introverted. Nature has a way of being diverse and inclusive of variety.
Up until this century we were in the dark about what goes on in our brain while we are asleep. The invention of magnetic resonance imaging has given us a tool to see the inner workings of our brain while we are unconscious. MRI scans of volunteers reveal which parts of the brain are active as they sleep. Walker laments that early-morning school schedules conflict with optimum brain development in our youth. The most positive benefit of a good night’s sleep happens near the end of that eight-hour stretch. Getting up early to catch the school bus lops off the good stuff.
There are two basic types of sleep that happen when we call it a day and hit the pillow. They are differentiated by the movement of our eyes behind our eyelids. Rapid eye movement sleep is when our dreams appear. This is when our minds open up to a broad panorama of information. Creative solutions to problems that vex us during the day are often sorted while we slumber.
Non-rapid eye movement sleep is the time when much of the restorative work is done in each of our bodies. The author cautions us about the risks of not getting enough sleep. Without that daily dose of recovery sleep, we are not running on all cylinders. He notes in an aside that the Guinness Book of Records no longer offers a prize for staying awake the longest. Sleep deprivation is downright dangerous. Both Ronald Reagan and Margaret Thatcher bragged about getting by on four or five hours sleep each night. They both succumbed to Alzheimer’s disease at the end.
I learn a lot in this book about how memory works. As we read and listen and observe, ideas fill our short-term memory. There’s a limit to how many things we can remember and keep in mind at once. As we sleep, what we have learned is transferred from short term memory to a more permanent long term storage site in the brain.
Sleep is important. Sleep is free. Your brain has much work to do as you sleep. Give it the eight hours it needs to do the job right.
