Photographic sleep

Photography: Joanna B. Pinho, National Geographic

In arid Mali, a Tuareg family sleeps in a tent.

You can experience "brain death" and "mental illness" at the same time! Dare you sleep? From shallow to deep, human beings have four periods of sleep every night, and there will be a crazy "REM" state. To outsiders, you seem to sleep soundly; In your subjective consciousness, the brain is actually acting recklessly again and again, releasing itself again and again, which is more enjoyable than a roller coaster, sometimes bringing you close to the state of "suspended animation" and sometimes making you more excited than when you are awake. ......

1-2 Sleep

We just fell asleep at this stage,

Sensory blur,

The brain stays active and starts the editing program,

Decide which memories should be kept and which should be discarded.

A total of about 86 billion neurons communicate with each other through electrical and chemical signals. When awake, neurons form a bustling large group, which is as dynamic as a thunderstorm at the cellular level; If they are excited steadily and rhythmically, neat ripple lines appear on the EEG, indicating that the work center of the brain has turned inward, away from the noise of sober life. At the same time, all kinds of sensory receivers are blocked, and we will soon fall asleep. This is 1 sleep, which is the shallowest end of sleep and lasts for about 5 minutes.

Photography: Magnus Winman

What makes us sleepy? The airtight cabin of the Sleep Research Institute of the University of Tsukuba in Japan enables researchers to accurately track the oxygen consumption of sleepers, then calculate their metabolic rate, and measure the influence of external factors (such as the brightness and color of ambient light) on the data. Finding the best conditions to trigger sleep may be the first step to cure insomnia.

Then, a string of sparks rose from the depths of the brain, shaking the center of language and consciousness-the folded gray matter in the cerebral cortex! This kind of electric shock of half a second at a time is called "sleep shuttle wave". As long as this wave of operation occurs, it means that the human body has entered the second stage of sleep.

According to the new theory, shuttle waves will give specific stimulation to the cerebral cortex, enabling it to preserve the recently acquired information. The more shuttle waves, the better people will perform the next day.

Photography: Magnus Winman

If you have just experienced something bad,

Don't fall asleep at once!

In the evening, we switch from recording mode to editing mode. The brain will actively identify which memories should be kept and which should be deleted, but this choice is not necessarily correct.

Sleep is very efficient in strengthening memory, which is not only reflected in the second stage, accounting for about half of the sleep time, but also reflected in the whole process of circulating sleep.

Photography: Tim Hetherington, Ma Genan

An American soldier sleeps in the Korengal Valley in Afghanistan. He had just finished his night mission in frontline base the night before.

For example, tired soldiers have just returned from a dangerous battlefield. Don't just lie down and fall asleep. Gina Bo, a neuroscientist at UCLA, believes that in order to prevent post-traumatic stress disorder (PTSD), these soldiers should stay up for six to eight hours before going to bed.

Photography: Magnus Winman

Mike Morris, an American veteran who served in Iraq for two rounds, wore an EEG measuring cap while sleeping and held his therapeutic dog Oliver. This study reveals the effects of animal companionship and sleep silence on mental trauma recovery.

If we fall asleep immediately after a great change, and some suffering experiences have not been digested psychologically, then they are more likely to enter long-term memory, and even affect our lifelong cognition.

Therefore, don't quarrel before going to bed, don't get angry, and don't take the initiative to cause unpleasant things. But if unhappiness is inevitable, please stay awake and buffer for a few hours before going to sleep!

Photography: piloska b

Stage 3-4 sleep

Go into a deep sleep,

In other words, this state,

It's not far from brain death!

No wonder the ancients in China called sleep a "small death".

Photography: Sebastian Walcott

Stage 4 sleep is not far from brain death!

The three-toed sloth dozes off every day 10 hour;

Fruit bats can sleep 15 hours;

A mouse-eared bat sleeps for 20 hours;

Giraffes sleep less than 5 hours;

Horses stand and sleep for a while at night, and lie down and sleep for a while;

The two hemispheres of dolphins take turns sleeping,

One side is always awake and never delays swimming;

Warship birds can fly and sleep while gliding!

Photography: Stephen Granzotto

In the Indian Ocean, more than 30 adult female sperm whales are taking a nap about 15 meters below the sea surface. They fall asleep in an upright position, ranging from a few minutes to dozens of minutes, while their cubs play on the sea.

It is an iron law of nature that a creature, from cetaceans to cells, can't run at full speed 24 hours a day.

Photography: Magnus Winman

Joe Dimander, 76, has been a truck driver for the past 20 years, sometimes driving all night. He said that such a job would make people "too tired to sleep". The World Health Organization once commented on night shift work, "It is likely to cause cancer to human beings".

For humans, the main recovery occurs in the third and fourth stages of deep sleep. Our cells secrete the most growth hormone during deep sleep, and we rely on this hormone to maintain bones and muscles all our lives. In addition, sleep is indispensable for maintaining body temperature, blood pressure and a healthy immune system.

Photography: Magnus Winman

Referring to scientific theory, Paris Philharmonic Concert Hall arranged the program "Sleep" with a minimalist lineup, aiming to lead the audience into a sweet rest state. The whole program lasted more than eight hours!

The neurons in the awake state are tightly packed together. After falling asleep, the volume of some brain cells will be reduced by 60% and the spacing will be widened. The intercellular space is a garbage dump of metabolic wastes-especially a substance called amyloid β-protein, which can interfere with the communication between neurons and is closely related to Alzheimer's disease. Only during sleep can cerebrospinal fluid wash away β -amyloid along the widened gap.

Photography: Magnus Winman

Various sleep-aiding "artifacts" are very popular among urban people in China.

While carrying out various brain repairs, our muscles are completely relaxed. In the fourth stage, we generally don't dream, and we may even feel no pain. Stage 4 Sleep is not far from coma and brain death. Although it is full of repair effect, it must not be greedy!

So we stay in stage 4 for about 30 minutes at most, and then the brain will kick itself up. At this time, we tend to go retrograde all the way, after three periods, two periods, and 1 period, until we regain consciousness.

Photography: Magnus Winman

An old man dozed off under the tree. Many middle-aged and elderly people are prone to drowsiness during the day because of the influence of sleep respiratory syndrome.

When you don't get enough sleep, the first part of your brain is the frontal cortex, which is the core functional area for us to make decisions and solve problems. People who don't get enough sleep are more likely to get angry, emotional and lose their minds. And taking a nap during the day can't make up for the lack of sleep at night; Anyone who is used to sleeping less than 6 hours a night has a higher risk of depression, stroke and mental illness; Lack of sleep is also directly related to obesity: if sleep is insufficient, the stomach and other organs will over-secrete growth hormone-releasing peptide, commonly known as "hunger hormone", which makes people eat more than they actually need.

Crazy "rapid eye movement" state

In fact, every night,

Will commit "mental illness"!

Because every night,

Urban rem.

Photography: Dawn Kish, National Geographic Creative

In the Grand Canyon, a lonely traveler fell asleep on the sandbar of the Colorado River.

REM sleep was discovered by Eugene Aselinski and Nathaniel Cleitman of the University of Chicago in 1953. Before that, REM was usually regarded as the deformation of 1 sleep, and it was not particularly important. However, the unique rapid eye movement (REM) period and the congestion of sexual organs that always accompany it have been reported many times.

In adults, the duration of rapid eye movement accounts for about one-fifth of all rest time.

Every time we experience REM rapid eye movement sleep, it is equivalent to committing mental illness! Mental illness is defined as a state characterized by hallucinations and delusions. Some sleep scientists say that dreaming is a state of mental illness-we see a scene that doesn't exist but believe it, and we are comfortable with time and space and people changing or disappearing for no reason.

Newborns can sleep 17 hours a day, but nearly half of the time is spent in a brain activity similar to REM. The pregnant fetus has been sleeping with REM for about a month since the 26th week. There is a theory that these dreamlike experiences in the early life are equivalent to the "software test" of the brain, which is to prepare for full online. This process is called teleintellectualization.

Photography: Colin montes, Minden Pictures.

This experienced Antarctic tourist sleeps in a recliner and enjoys the snow scene near amundsen sea.

During REM sleep, the human body no longer regulates the body temperature, and the internal temperature remains at the lowest point in the set range, and the whole body is frozen. The heart rate is faster than other sleep stages, and the depth is different. Muscles can't move except for a few parts-eyes, ears, heart and diaphragm.

Photography: Magnus Winman

In the National Children's Medical System Laboratory in Washington, USA, Francis Iowa, a boy of 10 years old, was covered with tubes and electrodes, waiting to turn off the lights and start an overnight sleep check. This examination is sleep apnea, that is, repeated symptoms of respiratory interruption after falling asleep.

We believe in incredible things in REM sleep because the management right of the brain is no longer in the logical center and impulse control area.

At this time, serotonin and norepinephrine were completely stopped. They are key neurotransmitters that enable brain cells to exchange information. Without them, people's learning and memory abilities will be seriously damaged and they will fall into a state of distorted consciousness.

Photography: Magnus Winman

In Sweden, hundreds of immigrant children, whose families are facing deportation, suffer from the so-called "obedience syndrome", and their inexplicable maladjustment includes autism, even if they do not respond to painful stimuli, they can only get nutrition through nasal feeding tubes, and some have to continue feeding for several years.

But this is different from a coma-like state like stage 4 sleep. In the rapid eye movement stage, our brain is fully active and consumes even less energy than when we are awake.

REM sleep is controlled by the limbic system deep in the brain, which can be said to be the primitive jungle in the field of thinking-our most savage and deepest instincts haunt here. Freud was right. Dreams do trigger our primitive emotions.

Photography: Magnus Winman

New memories are consolidated at night. What happens to the brain at night? The University of Tsukuba in Tokyo uses optogenetics's method to explore this problem-mice are genetically modified to have specific sensitivity to light, and then a single brain cell is activated and turned off by laser.

The limbic system contains our sexuality, aggression and fear, but it can also make us feel happy, joyful and loving. Although sometimes nightmares are more than good dreams, they are probably illusions. It's just that terrible dreams are more likely to touch the brain's instruction change system and wake us up.

Photography: Frank La Penner

When we fall asleep and start our first rapid eye movement sleep, the brain, the most exquisite and complicated instrument known in the universe, can finally do what we like happily. It completely activates yourself to play and dream! Some sleep theorists suspect that REM sleep is our smartest, most creative and freest time-

That is to say,

When you are asleep,

An hour or two in all,

Your brain finally liberated itself,

Start doing what you want.

At this point, the brain makes you a

A real little lunatic.

So, the brain is too naughty,

Dare you sleep?

At the end of the article, we must solemnly remind: we must dare to sleep! And have a good sleep on time! Although rapid eye movement makes people close to psychotic episode, and although the fourth stage of sleep is a virtual state of brain death, we must face this "small death" frankly-

After all, there is no "small death" and no big life.

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