The soothing and restorative effects of sleep are well accepted but what really happens when we sleep? More importantly, how can we use this knowledge to sleep better?
Sleep is not a uniform activity. Instead, it consists of several rounds of the sleep cycle. Broadly, this sleep cycle is made of two stages:
Non-Rapid Eye Movement (NREM) helps in memory consolidation and body recuperation
Rapid Eye Movement (REM) causes dreams, often characterized by the rapid movement of eyes under the eyelids
Usually, each sleep cycle lasts about 90 minutes. So on average, we should experience 4-6 sleep cycles every night. But the proportion of NREM to REM sleep varies from the first to the last cycle, with the first cycle having the least REM of around 10 minutes, and the last cycle having the maximum REM of up to 60 minutes. This is the reason why our most vivid dreams come right before waking up in the morning.
An Intro to the Stages
NREM can itself be divided into light sleep and deep sleep, but let’s keep things simple. It is in NREM where memory consolidation happens and helps us learn things from the day better. Therefore, it is recommended to sleep well before an exam, as it helps in retaining information. Also, in this phase, both the heart and the brain slow down.
REM on the other hand is also called “paradoxical sleep” as it involves more brain activity. As the inhibition functions and executive control of the pre-frontal cortex shut down during REM, our brain runs free to make more creative connections, and seemingly non-intuitive solutions pop up. This also leads to one of the most surreal experiences: dreams.
During REM, we start playing our emotional memories based on whatever occupies our minds, often leading to bizarre dreams, mostly emotional or linking recent experiences with memories buried deep down in the brain. For this reason, it is often advised to be careful about what we think about before going to sleep, and usually positive activities like gratitude journaling are encouraged.
A Word of Caution
Much of the realm of sleep and dreams still lies in the dark but one thing we are starting to realize is that apart from body repair and learning, sleep helps us make sense of life events as well, especially when we dream.
In fact, upon facing trauma when people say that “time heals everything,” it is most probably that “sleep heals everything” That said, it becomes even more important to protect the quality of our sleep.
While we have already discussed the pillars of good sleep, two things need the most caution:
1. Alcohol before sleeping:
Many people make it a habit to drink before sleeping, often thinking of it as a hack to fall asleep faster. But remember that alcohol is a sedative, and its mechanism of making you sleep is by shutting down brain activity
Contrary to the required activity during deep sleep and REM sleep, a shutdown brain cannot process or heal properly and hence your sleep will not be refreshing
Also, alcohol can sometimes cause fight or flight response mid-sleep, causing interruptions
2. Binge-watching at night:
Whenever you feel tempted to spend hours on binge-watching shows at night, remember that you are paying the price not just with time spent in front of the screen, but also with your well-being from sleep (more on this later)
Take care, and sleep tight! 🦥