Adults' Rem Sleep: More Or Less Than Children?

Sleep is a complex and mysterious body process that plays a crucial role in our overall health and well-being. While the specific sleep needs vary across different ages, it is evident that adults and children have distinct sleep patterns. This paragraph aims to delve into the question of whether adults have more REM sleep than children, exploring the differences in sleep architecture and the implications for memory, brain development, and overall health.

Newborns sleep for up to 18 hours a day

Newborns don't yet have a sense of day and night, and they won't sleep through the night until they are older. They also have different sleep cycles to adults, spending close to equal amounts of time in REM and non-rapid eye movement (NREM) sleep. Newborns spend roughly 50% of their sleep time in REM, while adults only spend 20% of their sleep time in this stage. As babies grow, they spend less time in REM sleep, and their sleep cycles start to look more like those of adults.

Babies spend 50% of their sleep in REM

Babies spend roughly 50% of their sleep time in REM sleep. This is a significantly higher proportion than adults, who only spend around 20% of their sleep in the REM stage.

REM sleep is the fourth of four sleep stages, characterised by relaxed muscles, quick eye movement, irregular breathing, elevated heart rate, and increased brain activity. It is also known as "active sleep" and is associated with dreaming and memory consolidation.

Newborns sleep for up to 18 hours a day, meaning they can spend up to 9 hours in REM sleep. This drops to 12-16 hours of sleep per 24 hours by the time they are 3-4 months old, with sleep becoming more adult-like.

The amount of REM sleep gradually declines as babies get older, but the change is slow. Some 9-month-old babies still spend 50% of their sleep in the REM stage. By the time they are 5 years old, children are sleeping for 10-11 hours a day, with no naps.

REM sleep is important for brain development, memory, and emotional processing. Babies need a lot of REM sleep because everything is new and fascinating to them, and their brains are quickly filling up with new memories.

Baby sleep is very different from adult sleep. Firstly, babies sleep a lot more than adults. They also sleep in short bursts throughout the day and night, rather than in one long block as adults do.

Baby sleep cycles are shorter than adult sleep cycles, lasting around 50-60 minutes compared to 90-120 minutes for adults. This means that babies return to light sleep every hour, which is why they are so easily disturbed.

Another difference is that babies tend to fall asleep in REM sleep almost immediately, whereas adults do not experience REM sleep until they have been asleep for around 90 minutes.

Understanding the differences between baby and adult sleep can help parents get their little ones sleeping better through the night.

Parents can help their babies develop mature circadian rhythms by exposing them to the right environmental cues. During the day, babies should be exposed to natural, bright light, and as evening approaches, the lights should be dimmed, and blue light avoided as it is particularly disruptive to sleep.

It is also important for parents to be patient and observant before responding to their baby at night. Babies in REM sleep may appear to be awake, but they are actually in a light stage of sleep and may settle back to sleep on their own.

Babies need more sleep than adults because they are growing and developing. Sleep plays a major role in a baby's cognitive development, and it is thought that the large amount of REM sleep that babies get is particularly important for brain development and memory.

Most babies start to approximate an "adult" sleep schedule between 3 months and 1 year of age, sleeping for longer periods at night and shorter periods during the day. However, this varies from baby to baby, and parents should not worry if their baby is not sleeping through the night before the age of 1.

Even after 1 year, it is common for babies to wake up at least once during the night.

Adults spend 15-20% of their sleep in REM

Sleep is essential for both physical and mental restoration. It allows our bodies and brains to rest, heal injuries, and repair issues that occurred while we were awake. During sleep, our brains reorganise and catalogue memories and learned information, making it easier to access and use them when we're awake.

On average, adults need seven to nine hours of sleep per night. However, this can vary from person to person, and some individuals may require more or less sleep. A typical adult sleep cycle consists of four stages: three non-rapid eye movement (NREM) stages followed by rapid eye movement (REM) sleep. Each cycle through these stages takes around 90 to 120 minutes, and adults usually go through four or five cycles per night.

REM sleep is the fourth and final stage of the sleep cycle. It is characterised by relaxed muscles, quick eye movement, irregular breathing, elevated heart rate, and increased brain activity. This stage of sleep is crucial for memory consolidation, emotional processing, brain development, and dreaming. While the name "rapid eye movement" comes from the quick side-to-side movement of the eyes during this stage, other parts of the body may also experience twitching or jerking.

While newborns spend about 50% of their sleep in REM, this proportion decreases as they grow older. By adulthood, people experience REM sleep for approximately 15-20% of their total sleep duration, which equates to roughly two hours each night. This reduction in REM sleep across the lifespan may be because adults lead more routine lives with fewer novel experiences to process during sleep.

Babies sleep in cycles of active and quiet sleep

During quiet sleep, newborns lie relatively still and their breathing becomes more even. They move around much less and are less likely to make noise, sleeping more soundly. Newborns spend about half of their sleeping time in each of these stages.

As babies grow older, their sleep cycles develop and change. By the time they are between 2 and 6 months old, they begin to experience the same sleep stages as adults, including the four distinct stages of sleep: NREM1, NREM2, NREM3, and REM. The first three stages are lighter stages of sleep, while the third stage is the deepest and most difficult to wake someone from. The fourth stage, REM, is when people dream.

By the time they are around 12 months old, babies are spending only 30% of their total sleep time in REM. This percentage gradually decreases, and by the time they are approximately 5 years old, their sleep architecture starts to mirror that of adults, with REM sleep making up about 20-25% of their total sleep time.

Adults have a single sleep cycle lasting 90 minutes

A single adult sleep cycle lasts 90 minutes, and adults typically go through four to six sleep cycles per night. Each cycle includes three stages of non-rapid eye movement (NREM) sleep and one rapid eye movement (REM) stage.

The first sleep cycle is often the shortest, ranging from 70 to 100 minutes, while later cycles tend to fall between 90 and 120 minutes. The first stage of sleep is when a person first falls asleep, which normally lasts just one to seven minutes. During this stage, the body has not fully relaxed, though body and brain activities start to slow with periods of brief movements. It is easy to wake someone up during this stage.

The second stage of sleep is when the body enters a more subdued state, including a drop in temperature, relaxed muscles, and slowed breathing and heart rate. Brain waves show a new pattern, and eye movement stops. Brain activity slows, but there are short bursts of activity that help resist being woken up by external stimuli. Stage two sleep can last for 10 to 25 minutes during the first sleep cycle, and each stage two phase can become longer during the night.

The third stage of sleep is deep sleep, and it is harder to wake someone up during this phase. Muscle tone, pulse, and breathing rate decrease as the body relaxes even further. The brain activity during this period has an identifiable pattern of delta waves. Experts believe this stage is critical to restorative sleep, allowing for bodily recovery and growth. It may also bolster the immune system and other key bodily processes. You spend the most time in deep sleep during the first half of the night.

The fourth stage is REM sleep, which is believed to be essential to cognitive functions like memory, learning, and creativity. REM sleep is known for the most vivid dreams, which is explained by the significant uptick in brain activity. Dreams can occur in any sleep stage, but they are less common and intense in the NREM periods. Under normal circumstances, you do not enter an REM sleep stage until you have been asleep for about 90 minutes. As the night goes on, REM stages get longer, especially in the second half of the night. While the first REM stage may last only a few minutes, later stages can last for around an hour. In total, REM stages make up around 25% of sleep in adults.

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