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Why We Sleep: The New Science of Sleep and Dreams Kindle Edition
'Astonishing ... an amazing book ... absolutely chocker full of things that we need to know' Chris Evans
'Matthew Walker is probably one of the most influential people on the planet' Evening Standard
THE #1 SUNDAY TIMES BESTSELLER
TLS, OBSERVER, SUNDAY TIMES, FT, GUARDIAN, DAILY MAIL AND EVENING STANDARD BOOKS OF THE YEAR 2017
Sleep is one of the most important aspects of our life, health and longevity and yet it is increasingly neglected in twenty-first-century society, with devastating consequences: every major disease in the developed world - Alzheimer's, cancer, obesity, diabetes - has very strong causal links to deficient sleep.
In this book, the first of its kind written by a scientific expert, Professor Matthew Walker explores twenty years of cutting-edge research to solve the mystery of why sleep matters. Looking at creatures from across the animal kingdom as well as major human studies, Why We Sleep delves into everything from what really happens during REM sleep to how caffeine and alcohol affect sleep and why our sleep patterns change across a lifetime, transforming our appreciation of the extraordinary phenomenon that safeguards our existence.
'Startling, vital ... a life-raft' Guardian
'A top sleep scientist argues that sleep is more important for our health than diet or exercise' The Times
'Passionate, urgent . . . it had a powerful effect on me' Observer
- LanguageEnglish
- PublisherPenguin
- Publication dateSeptember 28, 2017
- File size2899 KB
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Editorial Reviews
Review
—People
"This is a stimulating and important book which you should read in the knowledge that the author is, as he puts it, 'in love with everything that sleep is and does.' But please do not begin it just before bedtime."
—Financial Times
“A thoughtful tour through the still dimly understood state of being asleep … 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. 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’ … Why We Sleep mounts a persuasive, exuberant case for addressing our societal sleep deficit and for the virtues of sleep itself. It is recommended for night-table reading in the most pragmatic sense.”
—New York Times Book Review
"Fascinating ... Walker describes how our resting habits have changed throughout history; the connection between sleep, chronic disease, and life span; and why the pills and aids we use to sleep longer and deeper are actually making our nights worse. Most important, he gives us simple, actionable ways to get better rest—tonight."
—Men's Journal
“Walker is a scientist but writes for the layperson, illustrating tricky concepts with easily grasped analogies. Of particular interest to business owners, educators, parents, and government officials, and anyone who has ever suffered from a poor night’s sleep.”
—Library Journal, starred review
"Why We Sleep is simply a must-read. World-renowned neuroscientist and sleep expert Matthew Walker takes us on a fascinating and indispensable journey into the latest understandings of the science of sleep. And the book goes way beyond satisfying intellectual curiosity, as it explores the cognitive, health, safety and business consequences of compromising the quality and quantity of our sleep; insights that may change the way you live your life. In these super-charged, distracting times it is hard to think of a book that is more important to read than this one."
—Adam Gazzaley, co-author of The Distracted Mind, founder and executive director of Neuroscape, and Professor of Neurology, Physiology, and Psychiatry at University of California, San Francisco
“Most of us have no idea what we do with a third of our lives. In this lucid and engaging book, Matt Walker explains the new science that is rapidly solving this age-old mystery. Why We Sleep is a canny pleasure that will have you turning pages well past your bedtime.”
—Daniel Gilbert, professor of psychology at Harvard and author of Stumbling on Happiness
"In Why We Sleep, Dr. Matt Walker brilliantly illuminates the night, explaining how sleep can make us healthier, safer, smarter, and more productive. Clearly and definitively, he provides knowledge and strategies to overcome the life-threatening risks associated with our sleep-deprived society. Our universal need for sleep ensures that every reader will find value in Dr. Walker's insightful counsel."
—Mark R. Rosekind, Ph.D., former NHTSA Administrator, NTSB member, and NASA scientist
"A neuroscientist has found a revolutionary way of being cleverer, more attractive, slimmer, happier, healthier and of warding off cancer — a good night’s shut-eye ... It’s probably a little too soon to tell you that Why We Sleep saved my life, but I can tell you that it’s been an eye-opener."
—The Guardian
About the Author
Excerpt. © Reprinted by permission. All rights reserved.
CHAPTER 1 To Sleep…
Do you think you got enough sleep this past week? Can you recall the last time you woke up without an alarm clock feeling refreshed, not needing caffeine? If the answer to either of these questions is “no,” you are not alone. More than a third of adults in many developed nations fail to obtain the recommended seven to nine hours of nightly sleep.I
I doubt you are surprised by this fact, but you may be surprised by the consequences. Routinely sleeping less than six hours a night weakens your immune system, substantially increasing your risk of certain forms of cancer. Insufficient sleep appears to be a key lifestyle factor linked to your risk of developing Alzheimer’s disease. Inadequate sleep—even moderate reductions for just one week—disrupts blood sugar levels so profoundly that you would be classified as pre-diabetic. Short sleeping increases the likelihood of your coronary arteries becoming blocked and brittle, setting you on a path toward cardiovascular disease, stroke, and congestive heart failure. Fitting Charlotte Brontë’s prophetic wisdom that “a ruffled mind makes a restless pillow,” sleep disruption further contributes to all major psychiatric conditions, including depression, anxiety, and suicidality.
Perhaps you have also noticed a desire to eat more when you’re tired? This is no coincidence. Too little sleep swells concentrations of a hormone that makes you feel hungry while suppressing a companion hormone that otherwise signals food satisfaction. Despite being full, you still want to eat more. It’s a proven recipe for weight gain in sleep-deficient adults and children alike. Worse, should you attempt to diet but don’t get enough sleep while doing so, it is futile, since most of the weight you lose will come from lean body mass, not fat.
Add the above health consequences up, and a proven link becomes easier to accept: relative to the recommended seven to nine hours, the shorter your sleep, the shorter your life span. The old maxim “I’ll sleep when I’m dead” is therefore unfortunate. Adopt this mind-set, and it is possible that you will be dead sooner and the quality of that (shorter) life will be worse. The elastic band of sleep deprivation can stretch only so far before it snaps. Sadly, human beings are in fact the only species that will deliberately deprive themselves of sleep without legitimate gain. Numerous components of wellness, and countless seams of societal fabric, are being eroded by our costly state of sleep neglect: human and financial alike. So much so that the Centers for Disease Control declared insufficient sleep as a public health epidemic. It may not be a coincidence that countries where sleep time has declined most dramatically over the past century, such as the US, the UK, Japan, and South Korea, and several in western Europe, are also those suffering the greatest increase in rates of the aforementioned physical diseases and mental disorders.
Scientists such as myself have even started lobbying doctors to start “prescribing” sleep. As medical advice goes, it’s perhaps the most painless and enjoyable to follow. Do not, however, mistake this as a plea to doctors to start prescribing more sleeping pills—quite the opposite, in fact, considering the evidence surrounding the deleterious health consequences of these drugs.
But can we go so far as to say that a lack of sleep can kill you outright? Quite posssibly—on at least two counts. First, there is a very rare genetic disorder that starts with a progressive insomnia, emerging in midlife. Several months into the disease course, the patient stops sleeping altogether. By this stage, they have started to lose many basic brain and body functions. Few drugs that we currently have will help the patient sleep. After twelve to eighteen months of no sleep, the patient will die.
Second is the deadly circumstance of getting behind the wheel of a motor vehicle without having had sufficient sleep. Drowsy driving is the cause of hundreds of thousands of traffic accidents and fatalities each year. And here, it is not only the life of the sleep-deprived individuals that is at risk, but the lives of those around them. Tragically, one person dies in a traffic accident every hour in the United States due to a fatigue-related error.
Society’s apathy toward sleep has, in part, been caused by the historic failure of science to explain why we need it. Sleep remained one of the last great biological mysteries. All of the mighty problem-solving methods in science—genetics, molecular biology, and high-powered digital technology—have been unable to unlock the stubborn vault of sleep. Minds of the most stringent kind, including Nobel Prize–winner Francis Crick, who deduced the twisted-ladder structure of DNA, famed Roman educator and rhetorician Quintilian, and even Sigmund Freud had all tried their hand at deciphering sleep’s enigmatic code, all in vain.
To better frame this state of prior scientific ignorance, imagine the birth of your first child. At the hospital, the doctor enters the room and says, “Congratulations, it’s a healthy baby boy. We’ve completed all of the preliminary tests and everything looks good.” She smiles reassuringly and starts walking toward the door. However, before exiting the room she turns around and says, “There is just one thing. From this moment forth, and for the rest of your child’s entire life, he will repeatedly and routinely lapse into a state of apparent coma. It might even resemble death at times. And while his body lies still his mind will often be filled with stunning, bizarre hallucinations. This state will consume one-third of his life and I have absolutely no idea why he’ll do it, or what it is for. Good luck!”
Astonishing, but until very recently, this was reality: doctors and scientists could not give you a consistent or complete answer as to why we sleep. Consider that we have known the functions of the three other basic drives in life—to eat, to drink, and to reproduce—for many tens if not hundreds of years now. Yet the fourth main biological drive, common across the animal kingdom—the drive to sleep—has continued to elude science for millennia.
Addressing the question of why we sleep from an evolutionary perspective only compounds the mystery. No matter what vantage point you take, sleep would appear to be the most foolish of biological phenomena. When you are asleep, you cannot gather food. You cannot socialize. You cannot find a mate and reproduce. You cannot nurture or protect your offspring. Worse still, sleep leaves you vulnerable to predation. Sleep is surely one of the most puzzling of all human behaviors.
On any one of these grounds—never mind all of them in combination—there ought to have been a strong evolutionary pressure to prevent the emergence of sleep or anything remotely like it. As one sleep scientist has said, “If sleep does not serve an absolutely vital function, then it is the biggest mistake the evolutionary process has ever made.”II
Yet sleep has persisted. Heroically so. Indeed, every animal species carefully studied to date sleeps.III This suggests that sleep evolved with—or very soon after—life itself on our planet. Moreover, the subsequent perseverance of sleep throughout evolution means there must be tremendous benefits that far outweigh all of the obvious hazards and detriments.
Ultimately, asking “Why do we sleep?” was the wrong question. It implied there was a single function, one holy grail of a reason that we slept, and we went in search of it. Theories ranged from the logical (a time for conserving energy), to the peculiar (an opportunity for eyeball oxygenation), to the psychoanalytic (a non-conscious state in which we fulfill repressed wishes).
This book will reveal a very different truth: sleep is infinitely more complex, profoundly more interesting, and strikingly health-relevant. We sleep for a rich litany of functions, plural—an abundant constellation of nighttime benefits that service both our brains and our bodies. There does not seem to be one major organ within the body, or process within the brain, that isn’t optimally enhanced by sleep (and detrimentally impaired when we don’t get enough). That we receive such a bounty of health benefits each night should not be surprising. After all, we are awake for two-thirds of our lives, and we don’t just achieve one useful thing during that stretch of time. We accomplish myriad undertakings that promote our own well-being and survival. Why, then, would we expect sleep—and the twenty-five to thirty years, on average, it takes from our lives—to offer one function only?
Through an explosion of discoveries over the past twenty years, we have come to realize that evolution did not make a spectacular blunder in conceiving of sleep. Sleep dispenses a multitude of health-ensuring benefits, yours to pick up in repeat prescription every twenty-four hours, should you choose.
Within the brain, sleep enriches a diversity of functions, including our ability to learn, memorize, and make logical decisions and choices. Benevolently servicing our psychological health, sleep recalibrates our emotional brain circuits, allowing us to navigate next-day social and psychological challenges with cool-headed composure. We are even beginning to understand the most impervious and controversial of all conscious experiences: the dream. Dreaming provides a unique suite of benefits to all species fortunate enough to experience it, humans included. Among these gifts are a consoling neurochemical bath that mollifies painful memories and a virtual reality space in which the brain melds past and present knowledge, inspiring creativity.
Downstairs in the body, sleep restocks the armory of our immune system, preventing infection and warding off all manner of sickness. Sleep reforms the body’s metabolic state by fine-tuning the balance of insulin and circulating glucose. Sleep further regulates our appetite, helping control body weight through healthy food selection rather than rash impulsivity. Plentiful sleep maintains a flourishing microbiome within your gut from which we know so much of our nutritional health begins. Adequate sleep is intimately tied to the fitness of our cardiovascular system, lowering blood pressure while helping keep our hearts in fine condition.
A balanced diet and exercise are of vital importance, yes. But we now see sleep as a preeminent force in this health trinity. The physical and mental impairments caused by one night of bad sleep dwarf those caused by an equivalent absence of food or exercise. It is difficult to imagine any other state—natural or medically manipulated—that affords a more powerful redressing of physical and mental health at every level of analysis.
Based on a rich, new scientific understanding of sleep, we no longer have to ask what sleep is good for. Instead, we are now forced to wonder whether there are any biological functions that do not benefit by a good night’s sleep.
Emerging from this research renaissance is an unequivocal message: 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. Unfortunately, the real evidence that makes clear all of the dangers that befall individuals and societies when sleep becomes short have not been clearly telegraphed to the public. It is perhaps the most glaring omission in the contemporary health conversation. In response, this book is intended to help address this unmet need, and provide what I hope is a fascinating journey of discoveries. It aims to revise our cultural appreciation of sleep, and reverse our neglect of it.
Personally, I should note that I am rather in love with sleep (not just my own, though I do give myself a non-negotiable eight-hour sleep opportunity each night). I am in love with everything sleep is and does. I am in love with discovering all that remains unknown about it. I am in love with communicating the relevance of it to the public. I am in love with finding any and all methods for reuniting humanity with the sleep it so desperately needs. This love affair has now spanned a twenty-plus-year research career that began when I was a professor of psychiatry at Harvard Medical School and continues now that I am a professor of neuroscience and psychology at the University of California, Berkeley.
It was not, however, love at first sight. I am an accidental sleep researcher. It was never my intent to inhabit this esoteric outer territory of science. At age eighteen I went to study at the Queen’s Medical Center in England: a prodigious institute in Nottingham boasting a wonderful band of brain scientists on its faculty. Ultimately, medicine wasn’t for me, as it seemed more concerned with answers, whereas I was always more enthralled by questions. For me, answers were simply a way to get to the next question. I decided to study neuroscience, and after graduating, obtained my PhD in neurophysiology supported by a fellowship from England’s Medical Research Council, London.
It was during my PhD work, conducted mostly at Newcastle University, that I began making my first scientific contributions in the field of sleep research. I was examining patterns of electrical brainwave activity in older adults in the early stages of dementia. Counter to common belief, there isn’t just one type of dementia. Alzheimer’s disease is the most common, but is only one of many types. For a number of treatment reasons, it is critical to know which type of dementia an individual is suffering from as soon as possible.
I began assessing brainwave activity from my patients during wake and sleep. My hypothesis: there was a unique and specific electrical brain signature that could forecast which dementia subtype each individual was progressing toward. Measurements taken during the day were ambiguous, with no clear signature of difference to be found. Only in the nighttime ocean of sleeping brainwaves did the recordings speak out a clear labeling of my patients’ saddening disease fate. The discovery proved that sleep could potentially be used as a new early diagnostic litmus test to understand which type of dementia an individual would develop.
Sleep became my obsession. The answer it had provided me, like all good answers, only led to more fascinating questions, among them: Was the disruption of sleep in my patients actually contributing to the diseases they were suffering from, and even causing some of their terrible symptoms, such as memory loss, aggression, hallucinations, delusions? I read all I could. A scarcely believable truth began to emerge—nobody actually knew the clear reason why we needed sleep, and what it does. I could not answer my own question about dementia if this fundamental first question remained unanswered. I decided I would try to crack the code of sleep.
I halted my research in dementia and, for a post-doctoral position that took me across the Atlantic Ocean to Harvard, set about addressing one of the most enigmatic puzzles of humanity—one that had eluded some of the best scientists in history: Why do we sleep? With genuine naïveté, not hubris, I believed I would find the answer within two years. That was twenty years ago. Hard problems care little about what motivates their interrogators; they meter out their lessons of difficulty all the same.
Now, after two decades of my own research efforts, combined with thousands of studies from other laboratories around the world, we have many of the answers. These discoveries have taken me on wonderful, privileged, and unexpected journeys inside and outside of academia—from being a sleep consultant for the NBA, NFL, and British Premier League football teams; to Pixar Animation, government agencies, and well-known technology and financial companies. These sleep revelations, together with many similar discoveries from my fellow sleep scientists, will offer proof about the vital importance of sleep.
A final comment on the structure of this book. The chapters are written in a logical order, traversing a narrative arc in four main parts.
Part 1 demystifies this beguiling thing called sleep: what it is, what it isn’t, who sleeps, how much they sleep, how human beings should sleep (but are not), and how sleep changes across your life span or that of your child, for better and for worse.
Part 2 details the good, the bad, and the deathly of sleep and sleep loss. We will explore all of the astonishing benefits of sleep for brain and for body, affirming what a remarkable Swiss Army knife of health and wellness sleep truly is. Then we turn to how and why a lack of sufficient sleep leads to a quagmire of ill health, disease, and untimely death—a wakeup call to sleep if ever there was one.
Part 3 offers safe passage from sleep to the fantastical world of dreams scientifically explained. From peering into the brains of dreaming individuals, and precisely how dreams inspire Nobel Prize–winning ideas that transform the world, to whether or not dream control really is possible, and if such a thing is even wise—all will be revealed.
Part 4 seats us first at the bedside, explaining numerous sleep disorders, including insomnia. I will unpack the obvious and not-so-obvious reasons for why so many of us find it difficult to get a good night’s sleep, night after night. A discussion of sleeping pills then follows, based on scientific and clinical data. Details of new, safer, and more effective non-drug therapies for better sleep will then be described. Transitioning from bedside up to the level of sleep in society, we will subsequently learn of the sobering impact that insufficient sleep has in education, in medicine and health care, and in business. The evidence shatters beliefs about the usefulness of long waking hours with little sleep in effectively, safely, profitably, and ethically accomplishing the goals of each of these disciplines. Concluding the book with genuine optimistic hope, I lay out a road map of ideas that can reconnect humanity with the sleep it remains so bereft of—a new vision for sleep in the twenty-first century.
I should note that you need not read this book in this progressive, four-part narrative arc. Each chapter can, for the most part, be read individually, and out of order, without losing too much of its significance. I therefore invite you to consume the book in whole or in part, buffet-style or in order, all according to your personal taste.
It is worthwhile pointing out that this book is not designed to be a self-help guide. It is not written to target or treat sleep disorders, including insomnia. There are books that do this, and many of them will recommend speaking to a doctor if you suspect you have a sleep disorder. I am also very understanding of, and sympathetic to, those people who struggle with sleep and are most anxious about it. For these individuals, it is possible that their anxiety may increase when reading about the impact of insufficient sleep, including information contained in the book. I therefore want to alert the reader to this possibility, allowing for reader discretion on this matter.
In closing, I offer a disclaimer. Should you feel drowsy and fall asleep while reading the book, unlike most authors, I will not be disheartened. Indeed, based on the topic and content of this book, I am actively going to encourage that kind of behavior from you. Knowing what I know about the relationship between sleep and memory, it is the greatest form of flattery for me to know that you, the reader, cannot resist the urge to strengthen and thus remember what I am telling you by falling asleep. So 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.
I. The Centers for Disease Control (CDC) stipulates that adults need seven hours of sleep or more per twenty-four hours.
II. Dr. Allan Rechtschaffen.
III. Cirelli, C., and Tononi, G. (2008). “Is sleep essential?” PLoS Biology. 6, e216.
Product details
- ASIN : B06Y649387
- Publisher : Penguin; 1st edition (September 28, 2017)
- Publication date : September 28, 2017
- Language : English
- File size : 2899 KB
- Text-to-Speech : Enabled
- Screen Reader : Supported
- Enhanced typesetting : Enabled
- X-Ray : Enabled
- Word Wise : Enabled
- Sticky notes : On Kindle Scribe
- Print length : 344 pages
- Page numbers source ISBN : 1501144316
- Best Sellers Rank: #95,153 in Kindle Store (See Top 100 in Kindle Store)
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― from “Why We Sleep: Unlocking the Power of Sleep and Dreams”
Matthew Walker's "Why We Sleep" is one of the two most important books I have read in my life1. Having done a little stock trading along with having survived several tech industry "death marches," things which are quite antithetical to good sleep, I had little idea just how destructive to your health lack of sleep is. A few years back, however, I began to hear that lack of sleep was correlated with diseases such as Alzheimer's, but this did not strike me as convincing since correlation is not causation. Indeed, a little later, I heard about this book at work but was somewhat ambivalent. It's just going to tell me that doctors think sleep is essential but are vague as to why were my thoughts.
Luckily I noticed an episode of Sam Harris's podcast "Making Sense" in which he interviewed Walker. Since Sam Harris is a figure whose judgment I highly respect, and I know he is very discerning about whom he invites on as guests, I decided there was probably more of value to say about sleep than I initially thought.
Correlation and Causation
Walker's book makes a compelling case that sleep is the bedrock of good health. He convincingly demonstrates that lack of good sleep can lead to downward spirals in health with the development of health conditions that make it hard to sleep, leading to more serious health conditions due to lack of sleep, making it even harder to sleep… and so on into a vicious cycle. Walker is careful to lay out in detail when the causal mechanisms are well understood, as in the case of Alzheimer's and cancer, and when lack of sleep is currently a suspect, although the exact causal mechanism has yet to be established. By the end of the book, I realized, however, that sleep is so foundational that even a mere correlation to some bad health condition is enough to make lack of good sleep a prime suspect worth considering as a cause.
Organization and Style
According to Walker, "Why We Sleep" is organized so that later chapters can be read without a strict need to read earlier ones first. Thus, if you use sleeping pills and want to know why you should not, he says it is okay to and, indeed, encourages you to jump to that section right away. That being said, I found the writing style so engaging (with a few minor instances of excessive detail) and the content so important that I read it straight through. Having read it this way, my sense was that the book frontloads its most important content: It explains in detail, with specifics such as the chemicals involved, why you feel more tired at certain parts of the day than others. To give you the motivation to get good sleep, the deleterious effects of lack of sleep also come near the beginning of the book.
The Enormous and Far-Ranging Effects of Poor Sleep
The effects of lack of sleep go beyond just affecting your physical health, however, and Walker shows just how destructive lack of sleep will be on your ability to learn new things. One of the most remarkable findings is that you need to get good sleep after learning new information. You cannot even get a single night of suboptimal sleep the first night, or some information will be lost permanently.
Conversely, if you get that first night of good sleep after learning something new, sleep on subsequent nights will continue to solidify what you have learned: all while you sleep! This is just one case where Walker details how, unfortunately, missed sleep cannot be well compensated for by more sleep later: Permanent losses are involved.
Dreams
Some of the most fascinating information in the book is on the role of dreams. Here we learn of their therapeutic qualities, including some of the underlying biochemistry involved. Discoveries here have led to a better understanding of PTSD, including better treatment methods. Walker also describes how dreams foster creativity by establishing connections between distantly related pieces of information stored in the brain. Here Walker includes a particularly fascinating anecdote of how Edison enhanced his creativity by waking himself from naps and immediately recording his thoughts.
Empathy For Different Circadian Rhythms
Throughout the book, Walker emphasizes how what we have learned about sleep has implications for how we should view people who may not have what seem like "normal" sleep patterns more empathetically. In particular, he emphasizes that teenagers want to get up and go to bed later, not due to laziness but because they run on a different circadian rhythm. It is something that is biologically hardwired into them. A consequence is that forcing school start times incompatible with this has devastating effects on how well they learn compared to well they could. Similar facts are true of people who are naturally "night owls" and run on different circadian rhythms than the rest of us.
Minor Flaws
Walker's book has only a few minor flaws:
1. Although he provides an excellent explanation of why most sleeping pills should be avoided, he does not mention whether this includes melatonin.
2. His discussion of the nationwide dollar impacts of poor sleep could be better presented. The unfortunate truth is that given the numbers we have heard spent on wars and, especially, financial bailouts and stimulus, rattling off numbers that are “merely” in the hundreds of millions or even low billions hits us in a place we are now numb.
3. Although Walker's discussion of creativity in the dream state and the state when just waking from dreams is a fascinating part of the book, I would have liked to see some discussion of how objectively accurate intuitions are during these moments. Anecdotally, I used to joke that my best ideas came to me during this time or not at all. Sometimes, however, the thoughts just turned out to be overconfident upon more profound reflection. Is that true for just me, or is it true for people, generally speaking?
Conclusion
Overall, Walker's "Why We Sleep" is a must-read for anyone who sleeps: in other words, everyone. This book will not only absolve you of any guilt associated with prioritizing sleep, but it will also arm you with the knowledge to make the best choices for your physical and mental health. Walker guides you through the critical benefits of sleep, from its integral role in memory and creativity to its power to process and put to rest the day's experiences: especially the more troubling ones.
While the damaging effects of lack of sleep seem exponential, Walker argues that some of the most significant benefits come in the final two hours. Thus getting eight full hours of sleep is crucial. After reading this book, you will not want to miss a full night's sleep again.
To help you achieve a full night's sleep regularly, Walker provides 12 concrete steps in an appendix. Some of these suggestions are initially counterintuitive. For example, Walker maintains that a cooler room temperature of around 65F is best for optimal sleep. Already, I've been putting this and his other advice to the test, and the results seem promising.
The book is split into four, largely independent sections. The author begins by discussing how sleep occurs, including some of the neuroscience and the chemical cycles associated with our sleep schedule. The reader learns about the marginal differences between certain physiological cycles and the 24 hour day. In addition the causes of jetlag are explored as well as the required adjustment for changing time zones. The author discusses a bunch of experiments done where we were able to learn about our cicadian cycles and some of the differences in sleep requirements any cycle times by age. The author also highlights his novel view on how REM sleep was associated with human ability to light a fire which allowed them to sleep on the ground rather than be in an unstable position in a tree and this evolutionary advancement was essential for modern development. Perhaps, probably not, but the author truly is impassioned about the subject with strong views. The author then gets into why we need sleep and discusses with abundant experimental evidence, the benefits of sleep to cognitive abilities and the necessity of it for healthy living. Some remarkable pathologies are discussed, for example there was an individual who lost the ability to go to sleep and their body slowly lost its ability to function and the disease proved quickly fatal. The author highlights that the Guinness Book of World Records struck the longest period without sleep as a category due to its terrible health consequences and the author spends time on the consequences of lack of sleep to driving abilities highlighting the large number of fatalities that follow. The author also discusses the benefits of sleep to overall body health and gives substantial experimental evidence to the regenerative benefits of sleep to natural ailments. The author does highlight that sleep will not just cure cancer but simultaneously implicitly argues that it might. So the author, with evidence, strongly argues that sleep has the ability to help one regenerate far more than the general scientific community currently advocates. The author gets into dreaming and how sleep breaks up. He discusses how each form of sleep is required and they have different functional benefits. Furthermore the body needs for NREM and REM sleep differ in immediate priority but not in absolute priority and these results are discussed with experimental evidence for how the body catches up on sleep after being deprived. The author discusses multiple memory experiments that depend on prior sleep conditions and highlights the substantially better performance statistics of students who have had enough sleep prior to trying to learn facts. The author then discusses the consequences of sleeping pills, which are considered significant and detrimental. The author also clarifies the difference between sedation and sleep and makes it very clear that sedation is not sleep and does not serve as a remedy and can be counterproductive. Alcohol's detrimental effects are considered by their impact on sleep for example. The author goes through several common sleeping tablets and makes it clear he does not believe any are substitutes and argues they can become dependencies that create major long term problems. The author then discusses how much better the world could be if we all paid more attention to sleep and how overall productivity of the society could be enhanced. This sort of analysis is interesting but also in need of being the most skeptical of in terms of being a realistic analysis.
Why We Sleep is informative and entertaining. It is exaggerated at times and so aspects of the credibility of the book can be highlighted. The author argues multiple times how even one night of sub optimal sleep has distinct impacts on ability and how an all nighter can be catastrophic, only to bring up an example in which an individual goes without sleep for multiple days to then sleep and make a major scientific discovery. The point of the example was to display the benefits of sleep but it erodes the earlier argument that any lack of sleep puts the individual at a massive handicap. Thus the author argues too forcefully for the unrealistic, that we need 8 hours a day without exception, while highlighting that he himself often cant sleep properly once a week. Despite the at times marginally inconsistent tone, the book is a good reminder of the importance of sleep, a good reference for the scientific benefits of sleep and important tutorial on the health requirements for sleep.
I am looking forward to reading the entire book.
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I even subscribed to the Masterclass platform in part to watch his video Masterclass, which is essentially a condensed version of the book but to hear him talk with passion about his subject was very complementary to the book. He is very well articulated and speaks clearly.
Conclusion: Everyone should read this book. Sleep is so underrated in our society.