Why do we sleep? It’s a question which has been plaguing scientists for hundreds (if not thousands) of years. But it turns out that there’s a pretty simple answer to that question: for our brain health. There are a lot of very smart researchers who have been looking into the subject within the last decade or so. And they’ve all come to one very interesting conclusion: that the basic mechanics of sleep are all dedicated towards keeping our brains healthy and high-functioning.
Your Brain Needs Sleep to Be Healthy
So what is sleep? It’s a very specific state of unconsciousness in which the human brain repairs and restores itself. Basically, the longer you are conscious and the more active you are while you are awake, the more important it is to get enough sleep to let your brain recover. Your brain does this by going through several different sleep cycles each night. Each cycle is divided up into specific stages of sleep. There are different levels of light sleep and deep sleep, but the two that are the most important for your brain are delta (slow-wave) sleep and REM sleep.
Delta sleep is the most important for your brain’s physical health. It’s also sometimes referred to as slow-wave sleep because brain waves are their slowest and quietest during this stage of your sleep cycle. What happens during delta sleep is that your brain cells shrink to a fraction of their normal size. This creates extra space between each cell for your cerebrospinal fluid to pass more easily between – sort of like what would happen if you took the busy California highway and suddenly doubled the number of lanes for drivers to drive in.
The flow of traffic in your brain, however, is cleaning out the waste products and other toxins that are mucking up your brain cells. Not getting enough deep, delta sleep is like the garbage men in your brain going on strike. Scientists are even starting to believe that a chronic lack of delta sleep over years or decades could be a major contributing factor for early brain aging and diseases like Alzheimer’s.
For your mental and cognitive health, you need plenty of REM sleep, too. REM is short for “rapid eye movement”. REM sleep is the stage of sleep in which you dream. Sometimes it is referred to as paradoxical sleep because your brain is sometimes as active or more active than it is during regular, waking consciousness. This is because your brain is busy processing, separating, and storing the important memories and information you learned from the day. It also dedicates some energy to deleting old, unused information and pruning away unneeded neurons like dead branches off a bonsai tree. Without REM sleep, your memory and your cognitive function will start to decline. You get the most REM sleep towards the end of your sleep cycle and in the early morning hours before you wake up. So it’s important that you time your sleep in a way that allows you the most REM sleep possible – especially as you get older.
The Most Common Signs That Your Brain Isn’t Getting Enough Sleep
Do you know for sure whether or not your brain is getting enough sleep for optimal health? You may think you do. You may wake up in the morning feeling fresh the daisy and have plenty of energy throughout the day. It’s not always easy to figure out whether or not your brain is getting enough sleep. But if you notice any of the symptoms below, you should try to make an effort to get more sleep. If you notice most of the symptoms – or if any of the symptoms are severe – you may even want to have a conversation with your doctor:
- Moodiness or irritability
- Depression or depressive symptoms
- Inability to focus or concentrate
- Having a hard time remembering things
- You feel more clumsy and uncoordinated
- Slower reaction time
So there you have it. The human brain lives to sleep, and sleeps to live. In order to be your happiest, healthiest self, you need the right amount of quality, restorative rest. If you’ve been having trouble sleeping lately, we have plenty of articles you can read with helpful tips and suggestions. But if you’re more interested in brain health, we have plenty of information on that, too.
