How sleep helps our brain evolve

Facts about sleep

1. A snail can sleep for three years: The longest recorded sleep of any animal is that of the snail, which can sleep for up to three years.
2. Humans spend around a third of their lives asleep: This means that by the time you're 75 years old, you will have spent around 25 years sleeping.
3. Elephants sleep standing up: Elephants are one of the few animals that can sleep while standing up. They can do this by locking their knees so that they don't fall over.
4. Dreams can be in black and white: Although most people dream in color, studies have shown that a small percentage of people dream exclusively in black and white.
5. Sleepwalking is more common in children: Up to 15% of children are known to sleepwalk, while only around 4% of adults do.
6. Some animals sleep with only one half of their brain: Certain animals, such as dolphins and birds, are able to sleep with only one half of their brain at a time, while the other half remains awake to monitor their surroundings.
7. Lack of sleep can lead to hallucinations: After just a few days of sleep deprivation, it's not uncommon for people to start experiencing hallucinations.
8. Your body temperature drops when you sleep: Your body temperature drops by around one degree Celsius when you sleep, which is why it's often recommended to sleep in a cooler room.
9. The record for the longest time without sleep is over 11 days: The current world record for the longest time without sleep is held by Randy Gardner, who stayed awake for 11 days and 25 minutes in 1964 as part of a sleep deprivation experiment.
10. Snoring can be as loud as a pneumatic drill: Some people snore at a volume of up to 90 decibels, which is as loud as a pneumatic drill or a chainsaw.

why sleep is important

Sleep plays a critical role in the overall functioning of the brain and body, and the recommended amount of sleep varies by age. For example, infants and toddlers require up to 14 hours of sleep per day, while school-aged children need 9-11 hours, and adults typically need 7-9 hours of sleep per night.

Research has shown that the ratio of time spent in different stages of sleep is also essential for brain health. On average, healthy adults spend approximately 50% of their sleep time in NREM sleep, 20% in REM sleep, and the remaining 30% in a transitional state between NREM and REM sleep.

During NREM sleep, the brain waves slow down, and the brain replays and consolidates memories from the previous day. This process is crucial for learning and memory because it helps to strengthen neural connections in the brain. In contrast, during REM sleep, the brain waves speed up, and the brain processes and integrates new information, which helps to create new neural connections and build on existing ones.

Research has also shown that the ratio of NREM to REM sleep changes throughout our lifespan. Infants spend the majority of their sleep time in REM sleep, while adults spend more time in NREM sleep. This shift in sleep patterns is thought to reflect the changes in cognitive and neural development that occur as we age.

Overall, the ratio of time spent in different stages of sleep is crucial for brain health and development. By getting enough sleep and prioritizing healthy sleep habits, we can support our brain's evolution and optimize our overall well-being.