People spend their whole lives being tired, believing that sleep is something the brain can function without. But cutting a night of sleep short, even just by an hour or two deprives the brain of proper functionality.
Sleep is truly the backbone of our health. When our sleep quality crumbles, so too does our mental state of being. Poor quality sleep affects brain function drastically.
Thousands of sleep studies and in-depth scientific research has been completed in the last 100 years, all pointing to one solid fact. The amount of sleep you obtain directly impacts your overall health. In sum, the shorter you sleep, the shorter your lifespan will be.
Our awareness might slip away into a state of unconsciousness when we sleep, but that doesn’t mean our brain activity lowers in response. In fact, sleep scientists argue that sleep is when the brain does the most important work in a 24-hour cycle. Here’s why.
Sleep consists of two states of being- NREM and REM (non-rapid eye movement and rapid eye movement), each one responsible for different brain functions. When we catch those zzz’s at night, our brain cycles between these two states every 90 minutes. Achieving a full sequence of each state is paramount to the overall functionality of the brain.
During both NREM and REM sleep, the brain focuses on retaining what it has learned during that day. In NREM sleep, brain cells are ‘downloading’ all of the new knowledge and experiences gathered in the last 12 hours from short term memory storage to long term storage.
When awake, a part of the brain known as the hippocampus, or short-term memory storage, is responsible for storing all new memories of the day. However, the hippocampus has limited storage capacity.
Just like a small USB stick, it only has so much memory to use up before its full. During sleep, specifically NREM sleep, our brain cells take the new information stored in the hippocampus and downloads it into the brain’s long-term storage, known as the neocortex. Effectively sleep is transferring all the new memories on the USB, into the brain’s hard drive.
Individuals that do not achieve enough sleep at night cannot deposit all of their new memories into the neocortex, or long-term memory storage. This means that new knowledge or skills learned will not cement in the brain, and all of that work you did during the day could be worthless. Sleep scientists suggest napping after a tough learning session as a means to increase memory retention of this new knowledge. An added bout of sleep affects brain function positively in this instance.
Achieving the recommended sleep duration of 7 to 8 hours will help boost your memory retention. Failure to obtain quality sleep can result in the opposite. Scientists are continuing to discover new connections between chronic sleep loss and the development of Alzheimer’s disease.
Once brain cells have moved all of the day’s new memories from short-term to long-term storage, the NREM cycle is complete. Now, the brain moves into the REM state of sleep. It is during REM sleep, that our brain forms new ideas based on what was just learned that day.
REM sleep is responsible for making new connections between the newly stored memories in the neocortex with all other memories stored there from birth until the present moment. The neocortex is what governs our higher functions, from spatial reasoning and sensory perception to conscious thought and language.
Therefore, sleep is what helps us catalogue every experience and piece of information we have ever known. Night time is when our brain cells file away these new memories into their proper place so when our minds are awake, we have an easier time of connecting thoughts and creating new ideas.
REM sleep is when the brain regulates emotions and our state of mental well being. Those who have ever experienced an emotionally traumatic event tend to hear the saying, ‘time heals all wounds‘. In reality, it could be time spent sleeping that heals these wounds (emotional or otherwise).
It is during REM sleep that dreaming takes place, and it is during dreaming that the brain helps us to emotionally adjust to the previous days’ experiences. Dreams are intimately linked to our emotional concerns. Sleeping and dreaming quite possibly could be the brain’s own form of therapy.
Noradrenaline is a stress-related chemical produced in the brain. The only time production of this anxiety-causing molecule is ever stopped, is during REM sleep. It is at this time when the mind takes emotionally jarring memories, analyzing them again while in a state of emotional calm.
This process distances our visceral emotional response with that of the event. We then wake up feeling like we processed and resolved some of the trauma we previously felt. However, emotional resolution can only be found in a dream that reenacts the emotional state similar to that of the traumatic event. This is one of the biggest ways sleep effects mental health.
On top of regulating our own emotional state, achieving REM sleep also helps us read other people’s emotions. Again, REM is when we connect all of our past and present experiences to make new connections, this includes how we read social cues of others. People who do not achieve enough REM sleep every night will find it harder to distinguish between facial expressions and corresponding emotions.
Sleep loss can therefore effect a person’s social and emotional comprehension of the world. One study illustrates that lack of sleep causes people to read facial cues as more menacing and frightening than they actually are, even if its a friendly face. Consider how insufficient sleep will effect the mental state of lawyers, law enforcers, doctors, and even parents. If these people do not achieve the right amount of sleep, it will severely impact the way they do their jobs.
There is a reason why the World Sleep Organization recommends at least 7 to 8 hours of sleep at night. That’s how long it takes for your brain to cycle through the much-needed NREM and REM states, enacting each one of these responsibilities in turn.