Introduction
Sleep is a unique state during which several critical neurophysiological and chemical processes occur in the human body, affecting a person’s physical and emotional state. There is a consensus in the scientific community regarding the benefits of healthy sleep. The consensus on the effects of sleep on humans is that adequate sleep helps the human body to recover, supports the immune system, and helps accelerate metabolic processes. Moreover, people should pay special attention to the quality and quantity of rest necessary to realize the productivity, safety, and efficiency of a person’s daily life and minimize possible adverse effects on the health and condition of the body. A tremendous amount of research proves the negative impact of insufficient sleep on several human body functions. These studies affect all fields of medicine and psychology and are relevant for anyone of any age. As a result, sleep can be called one of the most critical conditions for maintaining brain performance, the violation of which can negatively affect human thinking abilities, health, and mental state.
Sleep Disturbance: Effects on the Brain
In the life of modern man, there are a considerable number of reasons why people suffer from insufficient amounts of sleep. The lifestyle of the twenty-first-century person often leads to sleep problems caused by much work, long hours on social networks, or other reasons. Forced or conscious sleep deprivation seriously affects a person’s mental and physical health. Even after one sleepless night, which has happened in the life of almost everyone, fatigue appears, concentration is reduced, and difficulties arise with complex activities. Movement coordination and visual focus are impaired if a person does not sleep for 2-3 nights (Grandner, 2017). Later, irritability, slowness of movements, slurred speech, hallucinations, and odd behavior appear. The person cannot maintain a conversation, becomes indifferent to the world around them, and there are difficulties performing the most straightforward everyday skills. Moreover, chronic lack of sleep often turns into insomnia, requiring the help of a specialist, as it can lead to the development of several mental illnesses (Harrington & Cairney, 2021). All of this confirms that quality sleep is essential to the human body.
Thus, if sleep is lacking quantitatively or qualitatively, a person begins to experience physical malaise, headaches, and irritability. Moreover, most people do not even suspect that the cause of their ill health is insufficient sleep. Such people must make up for the lack of sleep as soon as possible and restore their bodies. Otherwise, lack of sleep can cause irrational decisions in a person’s life, including crime (Engle-Friedman, 2018). Nevertheless, a logical explanation of this judgment requires an analysis of sleep disturbances’ impact on the brain’s elements: thinking, memory, and emotions.
Impact of Sleep on Thinking Ability
One should remark that sleep problems negatively influence some brain cells’ ability to function and interact, slowing down mental work in decision-making, information processing, focusing on vital details, and more. Lack of sleep disrupts the hormonal balance, changing the levels of serotonin, dopamine, and cortisol, which affects thinking, mood, and the amount of energy. According to Harrington and Cairney (2021), inconsistency of feelings and violation of the regulation of emotions, particular obsession, and persistence of “destructive” thoughts that exhaust the work of the brain are some of the consequences of lack of sleep, gradually weakening the downward inhibitory control over cerebrum regions. Insomnolence and restlessness violate prefrontal control over the medial structures of the temporal lobe, having “long-lasting results” – maintaining and exacerbating mental states within the framework of persistent unwanted reflections (Harrington et al., 2020). In this case, suppressing unpleasant ideas is one of a person’s most challenging tasks (Harrington and Cairney, 2021). As a rule, fear and obsessions are manifested throughout the day, intensifying closer to bedtime. Patients begin to worry and experience the most robust nervous excitement, leading to the fact that they can no longer fall asleep at their usual time of day.
Moreover, for most, concentration is a critical element for efficiency and purposefulness both at work and outside, and lack of sleep makes it more challenging to achieve. The experts claim that prolonged sleep deprivation decreases accuracy and reaction time to various cognitive tasks, breaking control over attention resources (Peng et al., 2020). For example, lack of sleep reduces the ability of cells to assimilate visual information and translate it into conscious thoughts; with insomnia, the reaction rate is as slow as when drinking alcohol. Unfortunately, such indisposition often becomes chronic, which leaves an imprint on abilities to concentrate, study and work well. Therefore, chronic lack of sleep is the cause of mood swings, and some patients even notice non–existent objects. Insomnia increases the concentration of stress hormones – adrenaline and cortisol- increasing blood pressure. The heart rate is disrupted, concentration is disrupted, and ordinary objects seem unusual. However, the consequences of such ailments are not limited to the effectiveness of cognitive abilities but also affect memory and emotions. Therefore, paying attention to these aspects in the following paragraphs is recommended.
The Effect of Sleep on Human Memory
Compromised sleep impairs the quality of learning and the capability to create new memories and reproduce them, regardless of when they were made – a month ago or a year ago. On the contrary, better sleep is associated with improved memory, knowledge acquisition, and learning. Even a short nap has a positive effect on productivity. Memory creation and reproduction occur in reality, but the middle stage, known as memory consolidation, starts in a dream. During sleep, data passes from short-term to long-term memory, a complex process with many stages (Peng et al., 2020). Besides, during sleep, the brain evaluates what happened during the day and decides what to leave in memory. Through this procedure, a human has an opportunity the next day to solve tasks of acquiring new memories through learning and exposure to stimuli.
As practice shows, sleep disorders do not allow a person to understand certain information better, reducing the likelihood of its assimilation and memorization. For instance, sleep problems can lead to the deterioration of short-term memory and a person’s ability to remember faces. To a sufficiently vivid degree, sleep deprivation is associated with a violation of the volume of a person’s working memory in terms of lower amplitude and prolonged latency (Peng et al., 2020). Due to the unsatisfactory quality of rest, the emotional valence of “recollections” suffers, giving rememberings negative affective shades (Tempesta et al., 2015). In this situation, insomnia may cause the most significant harm to episodic memory and the hippocampus, and their full normalization may require more than two nights of restorative sleep (Chai et al., 2020). Without getting enough night’s rest, a person can forget the most important and everyday things. Consequently, sleep-deprived people often do not understand the danger they expose their bodies to. Constant lack of sleep leads to decreased activity and efficiency and makes a human irritable and inattentive.
Influence of Sleep on the Emotional State of a Person
Fundamentally, poor sleep and insomnia significantly influence emotional response and socialization. According to Saghir et al. (2018), there is a deep connection between sleep and emotions due to the dual role of the amygdala. Normal physiological sleep is the most critical anti-stress factor determining performance or fatigue. On the contrary, sleep restriction contributes to the development of emotional stress, which is the leading cause of sleep disorders. At the same time, a vicious circle develops: sleep disorders caused by stress become an additional provoking factor that aggravates stress. In this case, incorrectness in emotion management and control may be a long-lasting negative effect of sleep deprivation (Harrington and Cairney, 2021). For example, lack of sleep increases impulsivity towards negative stimuli. Noteworthy, impulsivity correlates with aggressive behavior – a tendency associated with lack of sleep. Hence, anger is characterized mainly by poor quality and insufficient sleep.
Chronic stress and traumatic events are known for their adverse effects on sleep, leading to chronic sleep problems and insomnia. Chronic sleep loss, in turn, affects mood, making a person emotionally unstable, irritable, and prone to dysphoria. The interaction between sleep and emotional processes can also play a role in affective disorders, many of which are associated with sleep disorders. In the past, such sleep problems were considered a secondary affective disorder symptom. However, today, such a statement of the question may be exaggeratedly simple. In some cases, insomnia impacts the occurrence and development of depression. Moreover, there is evidence indicating the presence of a common source of both depression and insomnia.
In addition, the prefrontal cortex is mainly affected by lack of sleep; this part of the brain is responsible for planning and making complex decisions and allows one to conclude subtle nuances and confusing situations, weighing risks and winnings. Thus, without getting enough night rest, a person risks making rash decisions that do not consider long-term perspectives. Due to failures in the work of the prefrontal cortex, which is engaged in self-control, people are more likely to commit risky actions that can negatively impact relationships, health, or finances. Therefore, sound judgment, proper planning, and thoughtful decisions are the most critical cognitive skills that help individuals succeed at work and in their personal lives, build a stable and prosperous life, and lead according to ethical guidelines. Insufficient sleep weakens them, creating difficulties in happiness and success.
Conclusion
Thus, sleep is one of the most critical processes in a person’s life, directly affecting his thinking abilities, emotional state, and memory. In addition, healthy sleep affects the subjective mood of the person, who feels more awake, rested, and healthy. On the other hand, poor quality sleep leads to several problems in a person’s ability to reason, remember information, and communicate with others. Moreover, the prolonged occurrence of these phenomena can aggravate overall physical and mental health and even cause irreparable harm to the entire human body. One of the primary and universal recommendations given by doctors, nutritionists, athletes, scientists, and sportspeople is the observance of a correct sleep regime, the effect of which on a person is proved empirically and practically.
References
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