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 need to consider that we spend at least one-third of our lives in bed sleeping. Given that we live an average of 75–80 years, the total amount of 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 likes 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 available or have built a life so full of commitments that they end up putting sleep at the very bottom of their 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 every now and then—that we are able to recharge our energy, restore our hope, and rekindle our problem-solving skills and creativity. In the most extreme cases, sleep is viewed as a waste of time, as hours taken away from productive life and from monetizing 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 this topic—what it means to get too little sleep and what the real consequences are. For this reason, we tend not to truly realize how much a lack of rest can affect our 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 as opposed 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 replenish their energy. This misconception stems from the fact that, visually speaking, 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 a form of 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 secrets for specialists in neuroscience. Among the findings that can now be considered established is, essentially, 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 phases of sleep that alternate: REM sleep and non-REM sleep.
The states of consciousness experienced during non-REM sleep make up the bulk 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 neuroscientists 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, and this decrease becomes more pronounced as the sleep stages progress.
Stage 1
The first stage is the slow-wave 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 characterized 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) during 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 waves. With a frequency range of 0.1–3.9 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 sleep cycle transitions from the non-REM stage to the REM stage, which can be recognized by certain key signs. This is the stage during which dreaming typically occurs, and as a result, muscle activity is completely blocked—precisely to prevent the body from physically acting out the events of any dream one might be having.
However, breathing and eye movement continue, which is why it is called REM (Rapid Eye Movement).
Each cycle lasts about 1 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 dynamics.
According to recent studies, beyond the nighttime sleep cycle, it is possible to experience "localized 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 risks this may pose to our ability to carry out 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 drop” (rounds per minute)—the entire body begins to prepare for sleep. However, this model is not helpful for understanding what happens during certain 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, which may serve a specific function—inducing local synaptic changes that affect overall neural function.
This is the phenomenon collectively known 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 state, but is a mechanism of progressive sleep onset that begins in certain areas and gradually involves 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-Naps
Often, when discussing local sleep, people also refer to microsleeps. A microsleep 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 a 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 is over, the person wakes up just as suddenly, often with a start.
How are daytime sleepiness and micro-sleep 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 drowsiness, difficulty concentrating, heavy eyelids, and a vacant 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-sleep can be a dangerous condition for everyone, especially for those who perform physically demanding work or whose jobs involve responsibility for others. Improving the quality of your sleep not only prevents you from falling asleep in the wrong place at the wrong time, but also contributes to better health.
Risks Associated with Local Anesthesia
We have come to understand that local sleep is a common dynamic—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, thereby 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 localized sleep, various areas of the brain suddenly begin to shut down and enter a state of sleep. For this reason, it’s not possible to be 100% 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
Studies on this topic are fairly recent and are still ongoing. It appears that the primary cause of localized sleep is simple: lack of sleep. Lack of sleep has significant consequences for the brain’s state of fatigue, and certain parts of the brain simply shut down suddenly while the person is awake.
It is well known that lack of sleep causes significant declines in attention. Just think about how common it is to hear phrases like “I’m falling asleep on my feet,” “You’re so sleepy!” or “Wake up!” in everyday conversation. These usually refer to a state in which one feels confused or perceives that the other person is confused and not focused on what they’re 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 own behavior.
Quite a few scholars believe that it may also have some influence on the ability to manage aggression appropriately. It is possible that many cases of loss of 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 truly 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 process of learning and processing information also becomes more difficult. It is therefore possible that poor sleep is at the root of certain issues that affect those who struggle to spend much time studying.
Lack of Sleep: The Correlation with Other Medical 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 illnesses 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 verify that people who sleep only a few hours continuously strain 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 possible new area of research focusing on the correlation between sleep deprivation and antisocial behavior.
Given the biological importance of sleep, it’s not just essential to make sure you don’t get too little sleep. You need to approach sleep as a form of therapy for your daily well-being, and to do that, you’ll 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 this 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—in some cases, up to 17 hours.
Gradually, the need for sleep tends to decrease, until it reaches 9 to 11 hours 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 take place gradually and appropriately, with all necessary precautions in place. If you have difficulty falling asleep or enjoying a restful, uninterrupted sleep until the next morning, it is always a good idea to ask yourself a few questions:
* What is undermining the sense of calm associated with my feeling of having had a good night’s sleep?
* What is the atmosphere like in my bedroom? 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 problem isn’t solely related to the dangers of local sleep. In the long run, lack of sleep is harmful and increases our risk of developing serious illnesses.