Exploring the Necessity and Virtue of Sleep
WHY WE SLEEP
Unlocking the Power of Sleep and Dreams
You’re really asking for it when you name your book “Snooze” or “Why We Sleep.” A reviewer is tempted to dismiss the former by saying that it lives up to its title and the latter by replying, “Because of doorstop tomes like yours, pal!” Fortunately, the respective authors of these books — Michael McGirr and Matthew Walker — turn out to be good company: congenial, often funny narrators, each of whom, in his own way, offers a thoughtful tour through the still dimly understood state of being asleep.
Walker, a professor of neuroscience and psychology at the University of California, Berkeley, even goes so far as to pre-emptively acknowledge his book’s potential soporific powers. An evangelist for the mental and physical benefits of sleep, he writes, “Please, feel free to ebb and flow into and out of consciousness during this entire book. I will take absolutely no offense. On the contrary, I would be delighted.”
“Why We Sleep,” is a book on a mission. Walker is in love with sleep and wants us to fall in love with sleep, too. And it is urgent for him. He makes the argument, persuasively, that we are in the midst of a “silent sleep loss epidemic” that poses “the greatest public health challenge we face in the 21st century.”
Walker is no dilettante. He presides over Berkeley’s Sleep and Neuroimaging Lab, where he and his team, along with their peers at other institutions, have made significant strides over the last 20 years in understanding the restorative powers of sleep, and, correspondingly, the dire consequences of not getting enough of it. The upshot: “Sleep is the single most effective thing we can do to reset our brain and body health each day — Mother Nature’s best effort yet at contra-death.” Someone should put that last phrase on a T-shirt.
As information-dense as “Why We Sleep” is, Walker is adroit at presenting his findings and their implications in language accessible to the lay reader. A healthy night’s sleep lasts about eight hours, and is divided between REM (rapid-eye movement) sleep, in which the brain is as active as it is when its owner is awake, and NREM (non-REM) sleep, a deeper sleep state that predominates in the first half of the night. Both of these states (and there are further sub-states within NREM sleep) serve a multitude of purposes. NREM sleep, for example, is crucial to memory retention, and to acquiring and refining our motor skills. REM sleep plays a role in our abilities to overcome negative feelings, read other people’s emotions and solve problems.
By David Kamp