The main idea here is to provide a review of scientific research on sleep function of animals and especial of humans and demonstrate that this research provides a solid scientific prove that this function of a body is critically important for survival and health. It’s importance is probably somewhere in between breathing, without which animal would die in a few minutes, and food, without which animal would die in a few weeks. This book also demonstrates that sleep is way too complex phenomenon to try interfering in it with some chemical compounds either to promote or deny it. In both cases achieved results are superficial and mainly just imitate sleeping or waking without full providing required functionality of either state.
– Part1 – This Thing Called Sleep
Chapter 1 To Sleep…
This starts with reference to the importance of sleep and the general notion about it that one has to have some 8 hours, while people regularly have less than that. After discussing this general understanding, author refer scientifically proved consequences: short sleep=short live, persistent lack of sleep= death. Also, not enough sleep decreases performance in just about all areas of human activities, sometime with deadly consequences like micro sleep while driving. Then author discusses reason for animals’ need for sleep that have a lot to do with multiple tasks necessary to maintain body: it calibrates emotional brain circuits, cleans up brain in neurochemical bath, removing waste proteins, refreshes immune system, processes malignancies and sickness, and controls multitude of systems maintaining homeostasis of body including its weight. At the end of chapter author narrates how he come to sleep research and describes the structure of this book.
Chapter 2 Caffeine, Jet Lag, and Melatonin: Losing and Gaining Control of Your Sleep Rhythm
This chapter is about circadian rhythms, which are close, but not exactly the same as 24 hours, as it was established by experiments in conditions imitating absence of natural daily cycle of light and dark. Next author moves to melatonin, accumulation of which causes sleepiness and consequent dissolution of this chemical during the sleep. Similar effect has accumulation of adenosine. Author uses jet leg to discuss rhythms interruptions and then moves to mechanics of caffeine’s blocking receptors for adenosine, creating illusion of sufficient sleep. Author provides a number of graphics for various sleep related cycles.
Chapter 3 Defining and Generating Sleep: Time Dilation and What We Learned from a Baby in 1952
This starts with description of what sleep looks like and then moves to a more details of what is happening in the brain, with the most important part being kind of separation of brain activities from body movements and loss of consciousness. Contemporary sensors allow tracing what is happening in the brain. The findings are that it kind of replays activity that occurred during condition of wake. It also provided access for much more sophisticated reading of brain activity than it was at the time of original discovery of REM and NREM sleep. Here is the graph for typical activities:
Author compares functionality of different stages of sleep to rough cut of analysis of brain activities during a wake stage for NREM and then fine tuning and precise analysis for REM stage. During this process brain defines what is important and what is not, what to save in long term memory and what to discard, which new connections should be reinforced and which should be allowed to decay.
Chapter 4 Ape Beds, Dinosaurs, and Napping with Half a Brain: Who Sleeps. How Do We Sleep, and How Much?
This is about sleep patterns of animals with main conclusion that it is a necessary part of their existence not that different from humans. However, details are different and significantly: REM and NREM not the same. Some aquatic animals that need constant movement have split brain with one half sleeping, while another active. Another interesting pattern is in birds when flock members interchange their place in formation with birds inside formation sleeping, while automatically moving. However, REM sleep is not subject to splitting. The second part of the chapter is about natural patterns of sleep for humans. Author discusses natural sleep patterns as it observed in contemporary hunter-gatherers, which typically has 2 sleep periods: night and afternoon. Another specific of human sleep is that 20-25% of it is REM, which is much more than in other animals. Another interesting point is that humans sleep horizontally, while apes on the trees. Author posits that it provided for more REM sleep, which is conductive to more cognitive efficiency, social complexity, and creativity.
Chapter 5 Changes in Sleep Across the Life Span
This is about difference in the sleep patterns with age, starting even before birth when in utero child sleeps 6 hours REM, 6- NREM and 12 mixes of two. Young children have multiphase sleep with number of phase diminishing with age. The quality of sleep also changes with deep NREM sleep diminishing with age, eventually losing 80-90% of it. Also with the age increases fragmentation of sleep leading to wake-up periods in the middle of the night. Another issue is circadian timing leading aged people to go to sleep earlier. This decrease in quality of sleep has materially negative consequences for the health overall and should be taken care off to achieve maximal improvement.
– Part2 – Why Should You Sleep?
Chapter 6 Your Mother and Shakespeare Knew. The Benefits of Sleep for the Brain
Here author looks at sleep benefits for the brain working. The sleep before learning, and/or after learning improves memory functions and results. Even more interesting, it has a very positive impact on athletic functions. Here is a graph for NBA:
Probably the most important benefit of sleep is increase in creativity – well know fact that unresolvable problem that was excessively worked on before sleep somehow easily solved after a good sleep.
Chapter 7 Too Extreme for the Guinness Book of World Records: Sleep Deprivation and the Brain
This is about the other side: damage to the brain caused by sleep deprivation. The sleep deprivation could be not even consciously perceived, but damage occurs anyway. Here is a graph for driving:
Author discusses here usefulness of a nap and grades it as a positive, but limited measure. After that he reviews negative impact of sleep deprivation on emotional control and even long term consequences: insufficient cleaning of by products in the brain on regular basis could be one of the main causes of Alzheimer disease.
Chapter 8 Cancer, Heart Attacks, and a Shorter Life: Sleep Deprivation and the Body
The final chapter of this part links the sleep deprivation to a bunch of other diseases and even to obesity. At the end author discusses DNA relevance to the development of the sleep patterns and complexity of this issue.
– Part3 – How and Why We Dream
Charter 9 Routinely Psychotic: REM-Sleep Dreaming
This is about dreams, which is practically REM part of sleeping with NREM only 0-20% dreams relevant. Author discusses technological development in picking up brain activity that led to much better understanding of dreams, all the way to ability identify the content of the dreams by MRI data. From here author deviates slightly into intellectual history of dreams understanding from Aristotle to Freud with much more attention to the latter. The conclusion is basically that his theory of dreams is not falsifiable and therefore is not scientific.
Chapter 11 Dreaming as Overnight Therapy
Here author moves to contemporary understanding of dreams functionality. This chapter discusses functionality of dream and REM that support emotional and mental health. Author discusses very material changes in chemical cocktail that occurs in the brain during REM sleep. First of all stress related chemicals get shut off. Then it proceeds to rerun events of the day “divorcing bitter emotional rind from the information-rich fruit”. Author describes experiments confirming validity of this idea and links it to PTSD research and therapy. Another important function of REM is to decode experiences accumulated during the day that due to continuing flow of information could not be adequately processed during waking. It was also experimentally confirmed.
Chapter 11 Dream Creativity and Dream Control
Here author discusses how sleep provides for intelligent information processing. Author starts with the well-known story of Mendeleev who during the sleep was able to arrange chemical elements into the period table, which pointed to the new, yet unknown elements. Then he moves to explanation of this process, which comes from contemporary mathematical development of fuzzy logic and associative networks. Very interesting experiments with waking up people during various periods, demonstrated that NREM processing is logical, hierarchically connected, and associative, while REM create random combinations of fact, ideas, and notions sometimes obtaining non-obvious innovative solutions to the problems the brain is occupied with. The final result is the new model of reality in which there are unpredictable new connections between distant informational elements. This follows by discussion about dreams content and lucidity.
– Part4 – From Sleeping Pills to Society Transformed
Chapter 12 Things That Go Bump in the Night: Sleep Disorders and Death Caused by No Sleep
This is discussion of sleep disorders such as: Somnambulism, Insomnia, Narcolepsy, and Fatal Familial Insomnia. Author stresses that sleeping difficulties are not necessary mean Insomnia and provides specific boxes to check for this diagnosis:
There is also an interesting comparison between sleep and food deprivation with somewhat surprising point that lack of sleep kills faster than the lack of food.
Chapter 13 iPads, Factory Whistles, and Nightcaps: What’s Stopping You from Sleeping
This is about all characteristics of modern live that interfere with effective sleeping: all kinds of lights, multitude of electronic devices, alcohol, which creates illusion of sleep by sedating. One part of chapter is about temperature with recommendation to chill. There is also a bit of discussion of Alarm clocks and their negative impact.
Chapter 14 Hurting and Helping Your Sleep: Pills vs. Therapy
Main point here is that no known pill induces natural sleep. The sleeping pills mainly produce sedation, so the brain scans show completely different patterns of activity than natural sleep. Author recommends non-chemical methods of sleep therapy such as CBT-I (Cognitive behavioral therapy for insomnia).
Chapter 15 Sleep and Society: What Medicine and Education Are Doing Wrong; What Google and NASA Are Doing Right
This chapter provides recommendation for improvement in sleep patterns that could be provided by changing workplace, entertainment, education, medical services, and overall organizational modifications that could be done if sleep availability is a consideration. Author also stresses inhumanity of the use of sleep deprivation for punishment or interrogation.
Chapter 16 A New Vision for Sleep in the Twenty-First Century Conclusion: To Sleep or Not to Sleep
In this last chapter author discusses changes at different level that could facilitate improvement. He even provides a picture for comprehensive intervention at multiple levels and then discusses each level separately:
MY TAKE ON IT:
It is a valuable book and there is not much to have an opinion about here: the sleep is important for overall health and crucial for mental health and abilities. That’s all – end of story. I have this knowledge deep in my guts ever since I underwent a violent sleep deprivation for period of 5 months some 45 years ago as a soldier in Soviet army. This book just provides a scientific prove that my gut knowledge is correct.