We do the most important work in our sleep!
It's weird to think that we spend almost a third of our lives asleep. To some it may even seem like a waste of time in vain. That those hours of sleep, we could live and enjoy life.
While we sleep we look extremely unproductive, completely unprotected, surrendered.
In a sermon in 1719, Cotton Mather called excessive sleep ‘sinful’ and complained that we often sleep when we actually have to work. Benjamin Franklin echoed the expression that we will get enough sleep in the grave.
For a long time, the apparent uselessness of sleep entertained and kept busy even the scientists who studied it. Even Harvard sleep researcher Robert Stickgold recalls his former collaborator J. Allan Hobson jokingly saying that the only known sleep function is to cure drowsiness. Marcos Frank, a neuroscientist, summarized and analyzed the researchers' findings over the years. He concluded that science knew little about sleep and some of what it did know was unclear.
But over the years, the mystery seems to be fading.
By clearly seeing what can go wrong while we are asleep, we can understand what sleep is for. Paralysis also occurs in sleep. Apnea (stopping breathing for 10 seconds to a few minutes) occurs during sleep. About ten percent of the population experiences impairments during waking hours as a result of chronic insomnia, a condition that has been linked to poor quality of life, depression, increased cardiovascular disease and hypertension, cognitive and motor impairments, and a host of other conditions. health.
For sleep scientists, all of these unpleasant disorders provide attractive research lines. The link between many of them and neurodegenerative diseases, or other forms of cognitive impairment, make you realize that sleep is necessary for cognitive maintenance and functioning. Sleep can serve to relieve vascular stress. The fact that insomnia is linked to depression indicates that sleep can help us cope with stressful emotional events, even shock.
Increasingly, researchers have found ways to test these theories more directly. In 2000, Stickgold published a study in Science that became one of the most compelling proofs of the role sleep and dreams play in consolidating memory. For seven hours, over three days, a group of people played the Tetris computer game. Some had never played the game before; others knew him; and a third group were amnesiac with major damage to their temporal medial lobes and hippocampus. Their particular form of amnesia meant that they were unable to create new episodic memories.
Every night, as they slept, Stickgold subjects constantly woke up and were asked to remember, as far as they knew, what they were dreaming. It turned out that they were dreaming about Tetris. What was surprising was that even those with amnesia had the same dreams. They had no idea what they were seeing and the next morning they did not even remember the game and nothing. The only ones who remembered the next day, when faced with the game, were dreams with Tetris.
Yet sleep is not crucial just for consolidating memory; it is also an extremely selective mechanism. We do not remember everything that happens to us on a given day. By sleeping and dreaming we analyze material to isolate and preserve important things.
In another experiment, a group of people was given a relatively complex mathematical task. Although the subjects did not know how to solve it, there was a simpler way to solve the problem - an abstract rule that would enable a quick solution. Few of the subjects spontaneously understood the solution the first time. Each participant was retested eight hours later; some were allowed to sleep and others had to stay awake. Those who slept, did better to solve the problem. This shows that while we sleep, our brain reproduces, processes, learns and extracts meaning. So the brain works and so do we, even in sleep.
Our physical health, too, seems to be closely linked to sleep. Studies have shown that heart problems increase in insomnia.
But the importance of sleep for our brain function can be even more essential. In addition to memory and problem-solving functions, sleep can help our brain stay sharp, young and healthy. Researcher Maiken Nedergaard published the results of many years of research on sleep function. After using new techniques to look at the brains of awake and dormant mice, she discovered that sleep was actually the brain maintenance system. When we are awake, our activities lead to a build-up of waste in the brain: we form toxins, such as beta-amyloid, an Alzheimer-related protein, and other proteins that are usually harmless but must be removed from the brain. When we fall asleep, specific channels in our brain dilate to allow cerebrospinal fluid to drain and clear that waste. These mechanisms are called the 'lymphatic system'. Conversely, when our brain does not have enough time to rest, toxins accumulate and neurodegenerative disease appears. Indeed, one of the earliest signs of imminent dementia is sleep disturbances.
All of this research shows that the most important things happen while we sleep. And yet we know that few of us get enough sleep.