Too many people still don’t give sleep the importance it deserves, even though it is an essential time for the mind and body to recharge. If we look at it purely in numerical terms, we spend at least one-third of our lives in bed sleeping. Given that we live an average of 75–80 years, the total time we spend sleeping (or trying to sleep) amounts to at least 25 years.
Not getting enough sleep? The result of a battle with sleep
Everyone loves to sleep, and getting a good night’s sleep helps everyone feel better about themselves and like themselves more. Yet many people struggle with sleep every evening and every night. It’s a real battle that can last a lifetime, spent searching for solutions to their insomnia.
Others have little time to spare or have built a life so packed with commitments that they end up putting sleep at the bottom of the list, as the lowest of priorities. This is because we live in a society that pushes people to be constantly active and hyper-productive. Yet it is precisely through rest—and even those moments of leisure we allow ourselves now and then—that we are able to recharge our energy, restore our hope, and renew our problem-solving skills and creativity. In the most extreme cases, sleep is seen as a waste of time, as hours stolen from productive life and from the monetization of one’s activities. But a society in which sleep is seen as a nuisance, a problem, is not a healthy society.
In reality, even though as living beings we should be very familiar with sleep, few people know much about the subject—what it means to get too little sleep and what the real consequences are. As a result, we tend not to fully realize how much a lack of rest can affect our overall well-being.
When we think of sleep, we automatically contrast it with the waking state. We tend to think that wakefulness represents the moment of peak vitality for the body: an active state in which “things are done.” An active state in contrast to sleep, a passive state. This view is nothing more than the result of ignorance. We are making a serious error in judgment that stems precisely from a lack of knowledge about what happens during rest.
What happens while we sleep?
It is commonly believed that during sleep, the body and mind come to a complete standstill and finally rest in order to recharge. This misconception stems from the fact that, on the surface, we appear to be still, immersed in a state of partial or total unconsciousness. Yet sleep is not a form of total passivity; rather, it is itself an activity.
As scientific progress has advanced, we have uncovered new insights that shed light on the mechanisms of sleep. However, even today, sleep still holds many mysteries for neuroscientists. Among the findings that can now be considered established is the study of the different stages of sleep, from falling asleep to light sleep, deep sleep, and the REM stage.
But let’s take a step back. Within sleep cycles, we can distinguish two alternating sleep stages: REM sleep and non-REM sleep.
The states of consciousness experienced during non-REM sleep constitute the main part of nighttime sleep. In terms of duration, however, REM sleep accounts for roughly twenty minutes of each repeating cycle, which lasts about 90 minutes. As the cycles repeat, REM sleep takes up more time and gradually lengthens. But how do neuroscience experts analyze the various stages of sleep?
To distinguish between these two stages of sleep, researchers measured a series of parameters related to brain function and the activation of different brain regions.
While a person is sleeping, certain characteristics tend to change, such as muscle tone, heart rate, the electroencephalogram, respiratory movements, and eye movements.
During the non-REM sleep phase, these parameters decrease, with the decrease becoming more pronounced as the sleep stages progress.
Stage 1
The first stage is the sleep onset stage, which allows the individual to transition from wakefulness to sleep. This means that some significant changes can already be observed compared to the waking state. This is particularly evident in brain waves, which shift from alpha waves to theta waves.
Stage 2
The second stage is marked by a further increase in overall slowing, particularly of muscle activity—one is more isolated from the outside world, making it more difficult to wake up. During this phase, K-complexes appear; these are high-frequency, very short-lived waves that serve the important function of preventing the processing of information. K-complexes are followed by sleep spindles, characteristic signals detectable on the electroencephalogram (EEG) of stage 2 non-REM sleep.
Stage 3
The third stage is characterized by an increase in delta waves, which come to account for half of all brain waves. With frequencies ranging from 0.1 to 3.9 hertz, delta waves signal the onset of deep sleep.
Stage 4
Delta waves become predominant in the fourth stage, when brain activity can be considered “reduced” and the body’s metabolic rate is at its lowest.
REM sleep
About 90 minutes have passed since falling asleep, and finally, the body transitions from the non-REM stage to the REM stage, which can be identified by certain key signs. This is the stage during which dreaming typically occurs, and as a result, muscle activity is completely shut down—precisely to prevent the body from physically acting out the events of whatever dream one might be having.
However, breathing and eye movement remain intact, which is why it is referred to as REM (Rapid Eye Movement).
Each cycle lasts about an hour and a half—sleep cycles repeat at regular intervals 4–5 times throughout the night.
What is local sleep?
As you can see, the sleep cycle is a perfect mechanism, but there are many ways in which unhealthy habits and behaviors can disrupt its natural rhythms.
According to recent studies, beyond the nighttime sleep cycle, it is possible to experience local sleep during the day. This is a mechanism adopted by the brain, which automatically begins to shut down bit by bit, deactivating only certain specific areas.
So what does this mean? In a person who is, at least on the surface, awake, certain parts of the brain and specific areas of the cerebral cortex function differently, as if the person were asleep. In other words, even when awake, certain parts of the brain are “asleep,” with all the potential risks this poses to our ability to perform the normal activities of our personal and professional lives.
The causes and exact mechanism of the selective standby state induced by local sleep are not yet fully understood—it appears to be a combination of various neurological phenomena.
Sleep is, in fact, a complex neurological phenomenon. We are usually accustomed to thinking of sleep as a force that acts “from the top down,” starting in the brain and eventually affecting the entire body. In other words, when the brain calms down and slows its activity, the “RPMs” (revolutions per minute) decrease, and the entire body begins to prepare for sleep. However, this model is not helpful for understanding what happens during specific phenomena such as unilateral sleep (or hemispheric sleep), sleepwalking, and, indeed, localized sleep.
The function of local sleep
As we have said from the outset, some aspects of human sleep remain unclear to this day. For example, the slow, continuous oscillations of cortical neurons may serve a specific purpose—inducing local synaptic changes that affect overall neural function.
This refers to the phenomenon known collectively as sleep homeostasis, that is, the automatic mechanism that regulates the sleep-wake cycle.
In this sense, local sleep is not limited to the waking phase, but is a mechanism of progressive sleep onset that begins in certain areas and spreads to others. Following this logic, it therefore appears that sleep does indeed have a local component—that is, it can be triggered by a series of preparatory and learning processes involving specific brain regions. Thus, sleep homeostasis can be induced locally.
The Dangers of Micro-Sleeps
Often, when discussing local sleep, people also refer to micro-sleeps. A micro-sleep is a sudden episode of sleep (a nod-off) that lasts about 5–10 seconds. Without the person being aware of it, the brain goes into a pause and begins to sleep involuntarily. Micro-sleeps often occur when the person is performing a series of routine actions (watching TV, driving a car) or is otherwise in a situation considered monotonous, one that does not significantly engage brain activity. Once the micro-sleep ends, the person wakes up just as suddenly, often with a start.
How are daytime sleepiness and micro-sleeps related? Both phenomena stem from an initial state of sleep deprivation and stress caused by not getting enough sleep—specifically, when you don’t sleep for at least 7–8 hours a night.
There are, therefore, certain symptoms that local drowsiness and microsleep have in common. These include frequent yawning, a general feeling of sleepiness, difficulty concentrating, heavy eyelids, and a blank stare. Most people exhibit other signs either before or after an episode of microsleep:
* Failure to answer a question
* Slowness in understanding
* Blank stare and lack of focus
* Heavy head that droops
* Sudden body jerks
* Inability to recall the last few minutes.
Micro-sleeping can be a dangerous condition for anyone, especially for those who perform physically demanding work or have a responsibility for others. Improving your sleep quality not only prevents you from falling asleep at the wrong time and place, but also contributes to better health.
The risks associated with local anesthesia
We have come to understand that local sleep is a common phenomenon—a fundamental property of small neural networks, small areas of the brain that enter sleep-like states. These states are characterized by electrophysiological properties and molecular regulatory phenomena that constitute the essential component of sleep homeostasis. These processes, initiated by local events dependent on cellular activity, have repercussions at higher levels on tissue organization, influencing and regulating functions throughout the body.
The lack of in-depth studies and clinical applications related to local anesthesia currently prevents us from going any further. However, we can at least try to understand the risks associated with local anesthesia.
Being awake means being able to do everything that a human being does during their daily activities. Whatever action we consider always involves a certain need to be aware of and responsible for what we are doing. From the simple act of “sitting on the couch to watch TV” to slightly more complex tasks like driving a car or slicing salami at the deli counter in the supermarket.
When we experience local sleep, various areas of the brain suddenly begin to shut down and enter a state of sleep. For this reason, it is impossible to be fully present. And while this is one thing if it happens when we’re on the couch, it’s quite another if it happens while we’re performing tasks that could result in injury to ourselves or others—because then we become a danger.
The causes of local sleep
Research on this topic is fairly recent and is still ongoing. It appears that the primary cause of local sleep is simple: lack of sleep. Lack of sleep has significant effects on the brain’s state of fatigue, and certain parts of it simply shut down suddenly while the person is awake.
It is well known that lack of sleep causes significant drops in attention span. Just think of how common it is to hear phrases like “I’m falling asleep on my feet,” “You’re half asleep!” or “Wake up!” These usually refer to a state in which one feels confused or senses that the other person is confused and not focused on what they are doing.
And in fact, it might be much truer than the person using this kind of metaphor realizes.
Lack of sleep has a profoundly negative impact on a person’s cognitive abilities and their ability to control their behavior.
Many scholars believe that it may also have some influence on the ability to manage aggression effectively. It is possible that many instances of losing control stem precisely from severe stress caused by a lack of sleep.
Medical studies have found that when a person engages in an activity for a long time, their frontal cortical areas become fatigued. After a few hours, it is as if the brain tunes into the sleep frequency.
A person who experiences a local sleep attack thus begins to make a whole series of behavioral mistakes that they would never have made while fully awake.
These are temporary occurrences; the problem is that they cannot be controlled, so one cannot be certain of performing at a high level in those situations.
It goes without saying that, in cases of sleep deprivation, the learning process and data processing also become more difficult. It is therefore possible that poor sleep is at the root of certain issues affecting those who struggle to spend long periods of time studying.
Lack of sleep: the link to other health conditions
How many hours of sleep do people need? Numerous studies show how sleep deprivation or other sleep problems can be linked to disorders, including those of a psychopathological nature. This goes beyond depression or conditions that affect mood. For example, many people with personality disorders suffer from insomnia, although it is difficult to determine to what extent insomnia worsens the disorder or the disorder exacerbates insomnia.
Certainly, the doctors involved in the study on local sleep were able to confirm that people who sleep only a few hours are constantly taxing their brains. As a result, while awake, these individuals are more prone to entering a state of local sleep, a state in which they may have great difficulty managing human relationships and the impulses arising from them in a normal way. This suggests a potential new area of research focusing on the correlation between sleep deprivation and antisocial behavior.
Given the biological importance of sleep, it is not enough simply to make sure you get enough sleep. Sleep should be treated as a form of therapy for daily well-being, and to do so, you need to understand how many hours of sleep you need each day.
In fact, at certain times, our waking habits change, as do the cues that prompt us to wake up in the morning and the environment in which we rest. All of these factors can influence the amount of sleep a person needs at different stages of life.
To avoid experiencing micro-sleeps and entering an unintended state of local sleep while awake, you need to know yourself.
Not everyone is the same, and sleep needs can vary depending on the individual and their age. A newborn, up to three months old, needs to sleep at least 14 hours a day, and in some cases up to 17 hours.
Gradually, the need for sleep tends to decrease, eventually reaching 9 to 11 hours of sleep for school-age children. For most of a person’s life, during their working years, the amount of sleep required ranges from 7 to 9 hours, with the need decreasing by one hour after age 65.
However, this reduction must be gradual and appropriate, with all necessary precautions taken. If you have trouble falling asleep or getting a restful, uninterrupted night’s sleep until the next morning, it is always a good idea to ask yourself a few questions:
* What is undermining the peace of mind associated with my sense of restful sleep?
* What is the condition of my bedroom environment, and can I improve it?
* What material is the mattress I’m sleeping on made of? And the bedding?
As we answer these questions, let’s remember that the issue isn’t solely about the dangers of sleep deprivation. In the long run, getting too little sleep is harmful and increases our risk of developing serious illnesses.