THE MIND'S FUEL: SLEEP

Sleep is a state in which sensory activities and almost all voluntary muscle movements are suppressed, the level of consciousness is altered, and the individual can wake up in response to external stimuli. During sleep, sympathetic system activities slow down while the parasympathetic system is stimulated. Although sleep may appear to be a passive process, the brain is actually quite active. Throughout sleep, our body systems and cells are regenerated, and hormonal balance is established. Additionally, sleep is crucial for memory, learning, and emotional processes.

The Stages of Sleep
The stages of sleep are determined by parameters used to measure the brain's electrical activity, such as EEG. Sleep is divided into two main phases based on its characteristics: REM (Rapid Eye Movement) sleep and NREM sleep (Non-Rapid Eye Movement). REM sleep is also known as fast sleep, while NREM sleep is known as slow sleep. NREM sleep is further divided into four stages: stages 1 and 2 are considered light/superficial sleep, while stages 3 and 4 are known as deep sleep.

Stage 1: This is a short stage, lasting an average of 5-7 minutes, where we transition from wakefulness to sleep. Many people subjectively feel awake during this stage. Mental processes begin to change, and thoughts are not prolonged. Breathing is slow and regular, while heart rate decreases. It constitutes 5-10% of the total sleep duration.

Stage 2: This is a deeper phase of sleep compared to stage 1. Muscles are relaxed, and very little bodily movement is observed. It constitutes 40-50% of total sleep, making it a significant portion.

Stages 3 and 4 (Deep Sleep): In these stages, it is harder to wake the individual, and stronger stimuli are needed to do so. Physiological activity and metabolic processes slow down. One of the most well-known features of deep sleep is the increase in growth hormone secretion. The depth of sleep gradually decreases as we transition to the REM phase.

REM Sleep: Characterized by rapid eye movements, signals are sent to voluntary muscles, such as the arms, to relax them and prevent activation. This phenomenon is known as "muscle atonia." Most individuals awakened during this stage remember their dreams. It can be said that the NREM phase is related to physical renewal, while the REM phase is linked to mental renewal. In an adult, the REM phase, together with the NREM phase, repeats approximately every 90 minutes.

Sleep and Stress
The relationship between sleep and stress is reciprocal. It has been observed that individuals with high levels of perceived stress experience a decline in sleep quality and difficulty falling asleep. A decrease in sleep quality and insomnia can, in turn, trigger stress responses. Insomnia can negatively impact the body's stress response mechanism (HPA axis). As a result, this condition can lead to psychological and physiological problems in daily life, causing more stress.

Sleep Deprivation Experiments
Insomnia brings with it many physiological and psychological problems. Our immune system is negatively affected, making us more vulnerable to bacteria and viruses. Along with sleep deprivation, we begin to experience difficulties in cognitive processes such as memory, attention, and decision-making. We may struggle to communicate with others, our ability to empathize may weaken, and we may become more prone to psychological issues such as depression and anxiety. The importance of sleep and the question of what happens if we don't sleep have puzzled many researchers. As a result, sleep deprivation experiments have been conducted on animals such as rats and humans. Perhaps one of the most attention-grabbing experiments is that of Peter Tripp, who remained awake for 200 hours.

Peter Tripp
Peter Tripp was a man who worked as a DJ on a radio station in the U.S. in 1959. Tripp wanted to break the world record for the longest time spent awake and decided to stay awake while broadcasting on the radio. This decision drew the interest of the scientific community and doctors. During this period, Tripp's brain activity was recorded using an EEG device, and the 200-hour experiment began with Tripp under observation. Tripp didn't experience much trouble during the first 24 hours, but soon after, his gaze started to change, and he became more tense and cautious towards his surroundings. He could no longer regulate his body temperature. When he needed a shave, they brought his barber to the radio station, but Tripp didn't recognize him and chased him away. Shortly after, Tripp suddenly ran outside and started chasing cars. In the later hours, he began talking to himself and seeing hallucinations. When the EEG results were examined, the outcome was surprising: Tripp was dreaming—his brain was producing dream activities while he was awake!

Tripp eventually slept at the end of these eight days, but he had transformed into a more restless and tense man. He even lost both his job and his wife.

Sleep Hygiene
We probably all understand the importance of sleep by now. So how can we improve our sleep quality? The term sleep hygiene refers to behaviors that facilitate falling asleep and enhance sleep quality. So what are these behaviors, and how can we sleep better?

Exercise: Exercise, which has many benefits for both physical and mental health, will also help you fall asleep at the end of the day.

Nutrition: What we eat affects our bodies, and digestive issues can also impact our ability to fall asleep. Drinking a warm glass of milk before bed may help you fall asleep.

Caffeine: Caffeine blocks a receptor in the brain called "adenosine." Adenosine is associated with the feeling of sleepiness. Therefore, blocking this receptor makes it harder for us to fall asleep. This is how our beloved coffees keep us awake. For a more restful sleep, you can opt for herbal teas instead of caffeine.

Don't linger in bed: Shorten the time you spend in bed, and wake up at the same time every day. If you can't sleep, don't stay in bed for too long. Instead, you can read a book or engage in activities that relax you, like drinking chamomile tea.

SWEET DREAMS

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