Sleep is crucial for our well-being for numerous reasons and poor sleep has detrimental effects on our brain. Our survival demands work in this environment and to function efficiently, we need undisturbed sleep. Due to such competitive work environments and high expectations we set for ourselves, one thing we easily compromise on is sleep. Whether it is a student or a corporate employee, many of us have spent sleepless nights while studying or working and have felt groggy and uneasy the following day. We easily neglect the dangerous repercussions, it causes on our brains. In order to boost our productivity, we easily deprive ourselves of sleep. In this article, the Neuropsychological effects of sleep deprivation is explained with scientifically backed-up literature.
How does Sleep Deprivation affect the Human Brain?
Types of Sleep Deprivation:
Sleep deprivation (hereafter SD) can occur in many different forms in our lives. Scientific studies differentiate them into total sleep deprivation (absence of sleep) , chronic sleep restriction, and sleep disruption/fragmentation. Total SD basically means “no sleep” for a specific duration of time which can range from 1 night to even 72 hours in some studies. Chronic Sleep Restriction is when our sleep gradually reduces in duration with time and age when compared to the amount of sleep we need to function efficiently. Sleep fragmentation is when we get our sleep in bits and pieces and not continuously. This interruption in sleep occurs either in some disorders, such as apnea or insomnia, or when people live in loud and disturbed environments. All the 3 types have a negative effect with respect to cognition in humans.
The circadian rhythm:
Our sleep cycle (circadian rhythm) constantly alternates between two phases: REM (rapid eye movement) and Non-REM. The two phases break down into a few cycles, with each cycle lasting about 90 minutes. Each sleep cycle is very well-defined at a neurological level with specific cellular, anatomic and chemical changes taking place1. On average, a healthy human adult requires 7.5 to 8.5 hours of sleep every night5. Any disruption in this duration is harmful.
Cognitive and Emotional changes due to sleep deprivation :
When SD is studied at a macro level with a primary emphasis on neural functions, results not only report a drastic decline in cognitive abilities but also show negative moods. Total SD (any duration greater than 36 hours) significantly affects our performance across various cognitive tasks like executive decision-making, categorizing, spatial memory, fluid verbal expression, creativity, planning tasks, and detecting changes in our environment. Furthermore, it also causes fatigue, sleepiness, and pain along with bad moods and elevated stress levels.
The ability of humans to perceive changes in their immediate environment is disrupted over long periods of SD coupled with extremely slow reflexes towards external stimuli. In severe cases of SD, people also hallucinate and in some studies conducted on animals, SD has also led to death. Many scholars and researchers highlight the pitfalls of SD by focusing on the damage it causes to the prefrontal cortex, the region of the brain which connects the perceptual motor and limbic system and is also responsible for executive decision-making and attention.
Moreover, SD also heavily affects our memory as it potentially damages the hippocampus, the brain region responsible for consolidating information and converting it from short-term to long-term memory. Different neuro-imaging studies that made use of positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) have found that activity in the prefrontal cortex and thalamus is significantly minimized after long periods of SD. These structures have an important role to play in maintaining focus during executive performance. Recent findings have shown that SD also affects the ascending nuclei of the reticular system, which controls our physiological sleep-wake transitions.
Recovery from Short-Term Sleep Deprivation
Researchers have conducted extensive studies to examine the short-term effects of sleep deprivation (SD) on the human brain. They have observed that almost all behavioral deficits resulting from acute sleep deprivation return to normalcy after a maximum of 2 nights of complete sleep. Researchers have conducted numerous studies on mice to investigate the effects of chronic sleep deprivation, and they have found that chronic sleep deprivation can trigger the early onset of Alzheimer’s Disease and other forms of dementia. The human sample has also found that constant sleep deprivation causes the accumulation of beta-amyloid, tau-protein, and many other waste products in the brain, potentially leading to neuronal necrosis (death of neurons) and dementia
In this brief article, we have seen how sleep deprivation can harm the human brain. It not only damages the brain, but also affects our emotional, social, and work lives. Some ongoing research also claims that sleep deprivation causes our brain to age faster, and the repercussions of this is beyond our imagination. Sleep is like a spa for our brain. The human brain uses most of our oxygen and energy and when we don’t reward it with good sleep, the consequences are catastrophic. More than 50% of people in our nation are sleep deprived, so when individuals experience such problems, they should consider seeking treatment from a mental health professional. Therefore, sound sleep is a must which can help us in the long run and protect us from various threats.
