Core content?
In the past, we thought that human brain and body worked during the day and rested at night. But this book points out that the human brain runs continuously for 24 hours. When sleeping, the brain will automatically analyze, classify and store what we think, feel and do during the day, thus forming our cognitive structure. If we can make good use of this feature of the brain, we will improve our sleep and study efficiency.
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We are no strangers to sleep. Normal people should sleep at least once a day. I don't need to tell you how important sleep is: I didn't sleep well the night before, and I was listless all day the next day.
But it is such a thing that we do every day, but many people can't make practice perfect and get a good sleep every night. Can't sleep, easy to wake up, more and more tired, has become the trouble of many modern people.
Some people sleep well every day. So, they put forward a further demand: Is there any way for me to shorten my sleep time and improve my sleep efficiency?
In fact, most people know some sleep tips more or less, such as counting sheep when they can't sleep, and don't do strenuous exercise before going to bed.
But these skills are icing on the cake and can't help you. If you want to reverse your poor sleep quality and low efficiency, the key is to understand the scientific knowledge and operating principle behind sleep and find a way from the root.
The book recommended to you in this issue is the work of richard wiseman, a famous British experimental psychologist. On YouTube, Wiseman's psychological video has more than 65.438+0.5 billion hits. Our readers in China know him mainly through his other best-selling book, Weird Psychology. If you are interested in this book, you can listen to the interpreted version of the book you listen to every day.
In the book Night Brain, Wiseman discussed many problems related to sleep and dreams by relying on a large number of scientific experiments. For example, how to use sleep to improve memory, how to identify and avoid nightmares from a scientific point of view, and how to treat mental illness by manipulating dreams. But in my opinion, the most noteworthy thing about this book is that our brains will learn this idea automatically during sleep. In the past, we thought that human brain and body worked during the day and rested at night. But this book points out that the human brain runs continuously for 24 hours. When sleeping, the brain will automatically analyze, classify and store what we think, feel and do during the day, thus forming our cognitive structure. If we can make good use of this feature of the brain, we will improve our learning efficiency.
Because sleep research is a subject that is still developing at a high speed, in this interpretation, I will take you back to sleep on the basis of the original work and the latest views of the scientific community. My interpretation is divided into three parts. In the first part, let's first understand that a complete sleep cycle is divided into several stages, and what is the role of each stage. The second part tells us what we can do to meet the needs of sleeping well and sleeping efficiently. The third part is practical. I will introduce some tips to help you sleep.
first part
Ok, next, let's meet an old friend who accompanies us every day: sleep.
In fact, the special research on sleep did not start very early, because scientists could not find suitable observation instruments. Without instruments, scientists don't know how the brain works when people sleep. In the early study of sleep, the only material was the description of the dream a person had after waking up. The credibility of this material is so low that you can't be sure whether what the volunteers say is accurate or complete. You can't get first-hand information, let alone do research based on it.
From simple information arrangement to becoming a science, sleep research has gone through two very big turning points.
The first turning point appeared in 1924. This year, Hans Berger, a German medical scientist, first measured the weak current from the patient's head. However, he did not announce his findings for the first time. Because he needs to rule out other possibilities and make sure that these electrical signals are not from blood vessels, skin or heart.
In the next five years, he made many experiments and accumulated more than 1000 drawings. Finally, he confirmed that these electrical signals really came from the brain. Moreover, he further found that when people close their eyes, brain waves fluctuate periodically. When people open their eyes, there will be another periodic fluctuation.
Berger published his research results excitedly, but it didn't get the expected recognition. At that time, the scientific community was indifferent to his discovery, because no one believed that the brain could emit electric waves. However, later scientists tried to do Berger's experiment again, and it turned out that he was not lying. No matter what kind of equipment you use, you can record the two periodic ups and downs of opening your eyes and closing your eyes. Excited scientists have taken brain waves as their research objects, praising Berger as the "father of brain waves" and calling his discovery a milestone.
The second turning point of sleep research appeared in 195 1 year. This year, Aselinski, a graduate student at the University of Chicago, found that people intermittently have rapid eye movements while sleeping. At the same time of rapid eye movement, brain waves show that brain neurons are very active, just like when people are awake. If you wake someone up at this time, the other person will say that he is dreaming and tell the content of the dream in detail. Aselinski named this phenomenon "rapid eye movement period".
This discovery suddenly overturned all previous views on sleep. We used to think that when we slept, our bodies and brains were resting. But the discovery of rapid eye movement proves that the brain is active periodically even when sleeping.
According to the rapid eye movement, scientists divide sleep into five stages.
The first stage is called falling asleep, which is the beginning of sleep. You lie in bed and want to sleep. At this time, your brain wave frequency begins to slow down and your breathing begins to slow down.
In the second stage of sleep, during light sleep, your brain activity will gradually slow down, your heart rate will slow down, your body temperature will drop, your muscles will start to relax, and some people will start snoring.
The first two stages together, called light sleep, will last about 20 minutes. If you are tired recently or sleep in the wrong position, you may encounter a shallow sleep stage. You will feel that you are falling, and then your body suddenly shakes and you wake up.
This is because people relax their muscles when they sleep. After the brain receives the signal of muscle relaxation, it will misjudge that the body is in a state of falling. Because in the falling state, the body is also relaxed. At this time, the brain sends a signal to the body to make the muscles spasm to restore the upright state of the body.
After a shallow sleep for 20 minutes, the body slowly relaxes and prepares for a deep sleep. Next, you will enter the third and fourth stages of sleep.
The third and fourth stages of sleep, collectively called "deep sleep", last about 30 minutes. At this time, you are almost completely isolated from the outside world, and you won't be woken up unless someone calls your name or there is a lot of noise.
From lying down to getting ready for sleep, I experienced four stages of sleep in 50 minutes. Compared with the rapid eye movement period, scientists call the first four stages "non-rapid eye movement period". During the non-REM period, your body is calm and relaxed, and your brain will produce some fragmentary thoughts, but it will not produce complete dreams, so many artists use this stage to get inspiration. For example, the famous painter Dali likes to lie flat when sleeping, put a glass on the ground, then put one end of the spoon on the edge of the glass and hold the other end with his fingers. When he enters the first stage of sleep, his fingers will naturally relax and loosen the spoon. The sound of the spoon hitting the glass woke him up, and he scribbled down those strange images in his mind at once.
After the non-rapid eye movement period is over, your brain and body are active again. Your heart beats faster, your breathing becomes short, your eyes begin to move quickly from side to side, and you enter the rapid eye movement period that lasts for 20 to 30 minutes. This is the fifth stage of sleep.
When you enter the REM phase and finish your first dream, you complete a complete sleep cycle, which lasts about 90 minutes. After that, you will return to the non-rapid eye movement period, and the whole night's sleep will be repeated for 90 minutes. This is why some sleep methods suggest that you sleep for 90 minutes.
the second part
The human brain only accounts for 2% of the body weight, but it needs to consume 20% of the body's energy. If you don't sleep well, your brain can't think normally, resulting in premature physical and mental aging. After understanding the different functions of the five stages of sleep, let's look at the second part, how to sleep well and let sleep help you get twice the result with half the effort.
Need to remind you that sleeping is to keep your body and mind in the best condition. Therefore, to judge whether you sleep well or not, you should follow your own biological clock instead of taking the outside world as the standard.
Historians' research shows that before Edison invented electric light, most people's sleep was discontinuous. After a hard day's work, people went to bed as soon as it got dark. At about one o'clock in the middle of the night, people who regain their energy wake up from their dreams and begin a period of waking up that lasts for several hours. During this time, they relive their dreams or chat with their families. When I was tired of talking, I fell asleep again until I woke up the next morning. This sleep mode is called segmented mode.
However, the invention of electricity greatly extended the lighting time, which was originally an activity during the day and extended to the evening. Accordingly, people's sleep time is also delayed. The original mode of waking up in the middle of the night is becoming more and more unsuitable for the new lifestyle, so segmented sleep is squeezed out of daily life.
Living in modern society, we need to remind ourselves at all times. Our body's biological clock conflicts with social rules, such as clock time, industrialization, school timetable and work timetable. Some people are born in the morning and get up early. Some people are born night owls and sleep late. Some people even sleep in stages like people in the past. You can sleep as long as you want. After sleeping, you are in good spirits and active in thinking, so you don't have to worry about your sleeping habits.
If you don't work at home or work freelance and need to arrange sleep according to your work schedule, you can try to combine sleep. When you feel tired, try to take a nap during the day to rest your brain. Although the nap is not long, it can only make you enter the non-rapid eye movement period. However, non-rapid eye movements have a great influence on people's psychology and physiology, because they are closely related to the production of growth hormone, which can help repair damaged tissues.
So, when is the best time to take a nap in a day? The answer given by the author is that if you get up at 6 o'clock in the morning, then your perfect nap time is 1 30 in the afternoon. After getting up for half an hour every night, the nap time will be delayed by 15 minutes, and so on.
Sleep at night is also important. The author of this book believes that when we sleep, our brains will learn automatically. In fact, in the matter of self-study at night, sleep plays a role in storage. By automatic learning, he means that when you sleep, your brain will automatically analyze, classify and store what you think, feel and do during the day, thus forming your cognitive structure. Therefore, if you want to improve the learning level of the brain, you can try to extend the sleep time at night and increase the sleep cycle.
the third part
After introducing the scientific principle of sleep, the author of this book also gives some specific sleep tips. In the third part, I will introduce these skills in detail, hoping to help you control your sleep better.
If we want to sleep well at night, we should start making preparations during the day. Experiments show that moderate exercise during the day helps to improve the quality of sleep. Specifically, you need to do at least 150 minutes of moderate-intensity aerobic exercise or 90 minutes of strenuous exercise every week. Relatively vigorous exercise is suitable for 6 hours before going to bed. You can do yoga or simple stretching before going to bed.
The time to set the alarm clock is also very particular. A complete sleep cycle is about 90 minutes. You can take 90 as the unit to see how many sleep cycles you need and calculate a reasonable time to get up. For example, if you sleep at night 10, sleep for six cycles a night, set the alarm clock at 7 o'clock and get up at the end of the cycle, it won't be too difficult.
The last step before going to bed is to ensure that the surrounding environment is suitable for sleeping. Studies have found that when our eyes are exposed to light, the brain will reduce the production of melatonin that induces sleep. Therefore, you'd better turn off all the lights at home before going to bed. In addition, avoid the light from mobile phones and computer screens, because this color tends to the blue end of the spectrum, which will keep you awake and make it difficult to sleep. If you really can't help but want to play with your mobile phone, remember to dim the screen. If you think the light outside the window is bright, you can draw dark curtains or wear dark eye patches.
Sound is also important for sleep. If you live in crowded places, such as railway stations, airports, or windows facing the road, when you are ready to sleep, you can play some white noise similar to the sound of waves, which can drown out these traffic noises and help you sleep.
At this point, all the preparations have been completed, and you are lying in a comfortable bed, ready to sleep. From lying in bed to finally falling asleep, everyone spends different time. In order to help you judge whether the time you spend falling asleep is reasonable, the author puts forward the concept of "falling asleep efficiency" and gives a set of measurement methods. You can try it yourself. The whole measurement process lasted for 5 days. These five days, I don't take a nap during the day, but adjust my sleep time at night. Go to bed six hours before you plan to get up the next day. For example, get up at 7 o'clock the next morning and wait until midnight 1 o'clock to go to bed. After going to bed, let your family pay attention to recording when you fell asleep and how long you slept at night. After the test, you divide the average sleep time by the average time in bed, and finally get your "sleep efficiency". For example, if your average sleep time is 5 hours, but your time in bed is 6 hours, then your sleep efficiency is 0.83. If you calculate that your sleep efficiency is lower than 0.9, you will go to bed 15 minutes later in the next measurement cycle. If your sleep efficiency is greater than 0.9, go to bed 15 minutes earlier in the next measurement cycle. This is repeated until you sleep for about 7 to 8 hours every night, and your sleep efficiency remains above 0.9. If you want to fall asleep quickly, I'll tell you a very useful trick, which is to lie in bed and pretend to yawn.
abstract
At this point, the main contents of this book are introduced and finally summarized.
First, we learned about two turning points in sleep research. The first turning point occurred in 1924, when Hans Berger, a German medical scientist, measured a weak current from a patient's head for the first time, enabling people to observe brain activity in real time. Because of this, Berger was praised as "the father of brainwaves" by later generations. The second turning point appeared in 195 1, and Aselinski, a graduate student at the University of Chicago, discovered the "rapid eye movement period". This discovery subverts all previous views on sleep, and it proves that the brain is active periodically even when sleeping.
Secondly, we introduced five stages of sleep, namely, falling asleep, shallow sleep, deep sleep, deep sleep and rapid eye movement. These five stages constitute a complete sleep cycle, which lasts about 90 minutes. We slept like this all night and repeated the cycle for 90 minutes.
Next, let's review people's segmented sleep patterns before the invention of electric light. Obviously, the real way to sleep well is to follow your own biological clock, rather than paying too much attention to the various schedules of the outside world. If you want to regain your energy through sleep, you can take a combined sleep and take a nap during the day. If you want to improve your learning ability during sleep, try to extend your sleep time at night and add one or two sleep cycles.
Finally, I shared several sleep tips, including moderate exercise to help sleep, creating a good sleep environment before going to bed, and adjusting the sleep rhythm according to sleep efficiency.
Need to remind you that if your sleep problem is very serious, please go to the hospital as soon as possible to consult a professional doctor and receive regular treatment.