Understanding the Brain and Science of Sleep

Sleep plays a crucial role in maintaining good health and mental wellbeing. A lot of activity continues when you sleep, cells are revitalized, memory and learning are cemented, hormones are regulated, and dreaming helps you to emotionally deal with issues or make you laugh because they are so absurd. Understanding the science of sleep can help you understand just how important good quality shut-eye is to your physical health and mental wellbeing.      

the dreaming phase of sleep is full of activity, with your eyes moving rapidly, breathing is accelerated, heart rate and blood pressure increase

What Happens to the Brain During Sleep? 

Brain Sleep Stages

What happens in your head as you sleep? Brain activity changes through each stage of sleep

Stage 1-2: as you lay in bed waiting to fall asleep, your heart rate and breathing become more gentle and slow down. Your muscles and eye movements relax, and brain waves transition from wakefulness to light sleep.    

Stage 2-3: in this phase of light sleep, your muscles, heart rate, and breathing slow down even further. Your body temperature will drop and brain waves continue to slow down with the occasional spark of activity.  

Stage 4: in this phase of deep sleep your heart rate and breathing are at their lowest levels. This is a hugely restorative phase of sleep that replenishes physical energy. 

REM Sleep: the dreaming phase of sleep is full of activity, with your eyes moving rapidly, breathing is accelerated, heart rate and blood pressure increase, arms and legs immobile so you don’t try to act out your dreams. Memories are cataloged and stored during REM sleep and hugely beneficial to learning and cognitive processes. You will cycle through these types of sleep up to 6 times every night.


Sleep Mechanisms

Circadian Rhythm

Your circadian rhythms control your biological clock and tell you when to go to bed and when to get up. Along with controlling body temperature, hormone release, and metabolism. The environmental signals of sunlight and dusk, prompt your system to cycle through sleep and wakefulness.

Sleep-Wake Homeostasis

To regulate sleep, your homeostatic sleep drive alerts you to feelings of sleepiness and controls your sleep patterns like your circadian rhythm. Your sleep needs can change throughout your life, depending on work/study schedules, travel, medication, diet, or experiencing times of stress. Your sleep-wake homeostasis will help you to sleep longer if you’ve experienced sleep deprivation. Your eyes are the window to your soul but they also contain tiny cells that react to light and trigger your need to sleep. They also make it challenging to sleep in a bright room or during the day.   

Why REM Sleep Is Important  

Waste Removal

Your brain consumes a tremendous amount of energy and as your neurons help your body to function, there are inevitable waste products left behind. This discarded matter can hinder your neuron’s activity. For instance, have you ever struggled to focus on a task because of a lack of sleep? That’s because residual proteins are clogging up valuable space, causing disruption to your system’s processing abilities. Prolonged exposure to lack of quality sleep puts you at risk of cognitive deterioration. The fluid that surrounds your brain acts as a lymph cell, pulling damaging amyloid beta out of the brain and flushing it down ducts of the lymphatic system during deep sleep. 

Memory and Creative Problem Solving

Your creative problem-solving abilities are at their peak when you can easily recall knowledge. In order to access your knowledge database, it must be cataloged and stored. Deep sleep strengthens the structure of your database and cleans up your filing system, emptying the trash can, and neatly storing memories and knowledge in easily accessible drawers. Those who experience sleep deprivation, sleep apnea, or insomnia will experience cognitive impairment such as taking longer to complete a well-known task, sluggish reflexes, and poor memory recall. Long-term sleep disorders have been linked to dementia and Alzheimer's disease.  


Studies show that sleep also plays as essential role in creativity and problem solving. As explained in The Atlantic, "REM and non-REM—work together to help us find unrecognized links between what we already know, and discover out-of-the-box solutions to vexing problems." 

Decision-Making and Focus

Every day you make thousands of decisions as your brain is busy processing huge amounts of information and stimuli. These processes run smoothly when you’ve had a good night’s sleep. But, sleep deprivation affects parts of the brain that control learning and memory. Disturbing your natural ability to make quick, well-thought-out decisions. Focusing on a task is near impossible when sleepy, and driving while tired reduces your focus and reaction time and puts your safety and the safety of others at risk.    

Why Sleep Is Vital to Brain Function 

  • Clears out amyloid-beta (brain toxins)
  • Catalogs and stores memories 
  • Recalibrates hormones
  • Boosts creativity and problem-solving ability  

How Much Sleep do You Need?

To cycle through the restorative stages of sleep, aim for 7-9 hours of sleep per night. 

How to Get Restorative Sleep Every Night

  1. Create a sleep schedule that fits your timetable and lifestyle. 
  2. Be consistent with your sleep and wake times, even on your days off.
  3. Adjust your sleep schedule around daylight saving time and when you travel.
  4. Increase your exposure to light by walking in the fresh air every day.
  5. Limit day naps to a minimum of 20 minutes so as not to disturb your nighttime restorative sleep.
  6. Wind-down well every evening for 1 hour before bed, this can include a hot bath or shower, reading a book, light yoga or stretching, meditating, or listening to soft music. 
  7. If you have trouble falling asleep, get up and make hot milk with honey or read a few pages of your book until sleepy.    


The relationship between your brain and body can be improved significantly by maintaining a strict sleep schedule. While a quick cat nap during the day can be sufficient to boost energy, it is not a long-term sleep strategy. Only sleeping for 7-9 hours every night can improve brain function, physical health, and mental wellbeing. When you reach that time of day when your eyes are falling down and sleep is ushering you to bed. Resist the urge to binge-watch another episode of your favorite show and sleep, your brain and body will reward and thank you for it.

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