How Sleep Helps In Brain Development

As a parent, do you worry about your kid's sleeping time or whether your baby's sleep hours are regular and adequate? Insufficient sleep can be the cause of many ailments, especially as your child grows older. Poor health, depression and obesity are some of the obvious risks, but there are other problems a child may suffer from because of inadequate sleep. A child's sleeping needs keep changing as he grows older. So, it's important for parents to know his child's sleep requirements by age.

One of the most important factors why children must get enough sleep is because it's important for their brain development. Today, there is enough scientific evidence to show that improper kid sleep patterns can cause delays in cognitive development. Sleep disorders in children may cause problems with concentration, memory, spatial awareness, reading and math skills. So, the importance of rest and sleep for children can't be stressed enough.

Decoding the baby brain

Early childhood is a crucial period for brain development because new connections are formed between brain cells. As your child grows and has newer experiences, the brain goes through structural changes and grows with her. So, the total number of hours of sleep for kids changes with age.

The importance of sleep in child development

Dr Jamuna Rajeswaran, Professor and Head of Clinical Neuropsychology and Cognitive Neuroscience Centre, and Dr Cathlyn Niranjana Bennett, Senior Research Scholar, Clinical Neuropsychology and Cognitive Neuroscience Centre from the Department of Clinical Psychology, NIMHANS, help us understand the important relationship between sleep and brain development.

The development of the brain begins soon after conception, continues after birth, and carries on through adulthood.

"Scientists at Harvard University suggest that over one million new neural connections (brain cells) develop every second in the early years of life," says Dr Jamuna.

There are several factors that influence brain development. While genes are perhaps the most influencing determinants, a child's early experiences and his environment also play important roles.

"Studies show that children with nurturing parents have more grey matter (better intelligence) than those who are neglected," explains Dr Cathlyn.

Dr Cathlyn adds that healthy food habits, proper nutrition and good sleep practices are key elements for the developing brain.

The brain-sleep connection

How many hours should a baby sleep? This is a common question most new parents worry about. A newborn normally sleeps for about 16 to 20 hours a day. While it may appear that your infant is snoozing, the fact is his brain is busy and active. It is during sleep that brain cells grow, connect and communicate, thus increasing the size of the grey matter. The connections between his left (logical) brain and right (emotional) brain are strengthened during his sleep.

"Sleep is no longer considered a passive activity or a state of rest for the brain. The brain is as active when we are asleep, although the activities involved are different from those when we are awake. Sound sleep is also associated with brain plasticity, which refers to the ability of the brain to produce new neurons and form fresh neural connections," says Dr Jamuna.

Types of sleep

So, what exactly constitutes good sleep? To understand this better, let's first consider different types of sleep.

Non-rapid eye movement (NREM) sleep: This type of sleep is also known as quiet sleep. The body goes through three phases while experiencing NREM sleep.

1. During the first phase, one experiences a state of drowsiness. Your eyes are closed but you can wake up at the slightest noise.
2. The drowsiness carries into the second phase of light sleep, where your heart rate and body temperature drops.
3. Finally, the body shifts into the third phase, which is that of deep sleep. During this phase, the body restores energy, repairs and regrows tissues, grows muscles, and secretes essential hormones for growth and development.

Rapid eye movement (REM) sleep: This type of sleep is also known as active sleep. REM sleep occurs in the first 90 minutes after a person falls asleep and then the body goes through all three stages of non-REM sleep.

REM sleep is characterised by rapid back and forth movement of eyes beneath the eyelids, and hence the name. The breathing becomes faster and irregular, and the heart rate and blood pressure increase to near-waking levels. The brain becomes increasingly active and your child begins to encounter vivid dreams. The arm and leg muscles deeply relax and become almost immobile, which prevents the child from acting out the dreams. As the child grows up, the time spent in REM sleep gradually decreases.

Memory consolidation most likely requires both NREM and REM sleep. Younger children experience cycles of light and active sleep alternately, with each stage lasting for about 30 to 50 minutes.

As children grow older, these cycles gradually lengthen. Sometimes, the child may wake up for brief periods at the end of each cycle. This is normal, as most infants go through shorter sleep cycles, experience more light sleep and wake up often.

The duration of sleep also grows longer, as children advance from infancy to preschool age. Simultaneously, the number of naps throughout the day decreases.

So, if you are wondering how to make your toddler sleep and ensure she gets enough rest, it is essential that you establish a proper sleep schedule and help her wind down before her sleep time. This will help in creating and strengthening various memories during these sleep cycles.

Sleep requirements by age: tips to ensure a good night's sleep for your child

Dr Cathlyn believes that although every child has varying sleep requirements, there are a few things to look out for, to understand if a child is getting adequate sleep:

1. Duration of sleep: Is your child getting enough sleep?
2. Quality of sleep: Is his sleep uninterrupted?
3. Does he feel rested after sleeping?
4. Does he nap during the day?

Sleep tips for kids

Dr Jamuna suggests a few tips for creating a good sleep routine for your child and how to make kids sleep.

1. Ensure regular sleep time: Children thrive when there is order and predictability. Have a specific bedtime and nap time schedule for your child. This would make it easier for him to fall asleep at approximately the same time every day.
2. Follow healthy bedtime practices: Bedtime rituals instil a sense of familiarity and comfort in children. Putting on pyjamas or reading a bedtime story helps the child prepare for sleep.
3. Cut down stimulation: When your child is nearing sleep time, reduce activity and stimulation. Dim the lights and reduce any unwanted noise, which will help the child move from an active state to a relaxed state.
4. Stay active during the day: Help your child understand the difference between day and night by associating daytime with more stimulation and activity. This helps the child's internal clock or circadian rhythm (refers to the 24-hour cycle in the psychological processes of human beings) synchronise with the change between day and night.
5. Focus on nap time: Some parents believe that naps during the day interfere with night-time sleeping. This is a misconception. An overly tired child may find it more difficult to settle down to sleep at night. Your child will not need as many naps as he grows. Yet his age-appropriate afternoon naps will help in ensuring a good night's slumber.

Sleep needs by age

0 to 4 months

• Daytime sleep: 7-9 hours (4 to 5 naps)
• Night-time sleep: 8-9 hours
• Total hours of sleep: 15-18 hours

Sleep in 2-4 hour intervals, waking up in between for feeds.

Common for them to move, twitch or smile as they have no control over their reflexes.

4 months to 1-year-old

• Daytime sleep: 4-5 hours (2 to 3 naps)
• Night-time sleep: 9-10 hours
• Total hours of sleep: 12-15 hours

Usually more settled in a sleep schedule.

After 6 months, likely to sleep through the night without waking up to feed.

1 to 2-year-old

• Daytime sleep: 2-3 hours (1 to 2 naps)
• Night-time sleep: 11 hours
• Total hours of sleep: 11-14 hours

Since children are active at this stage, make sure they wind down before bedtime

3-year-old to 5-year-old

• Daytime sleep: 0-1 hour (daytime naps usually stop by 5 years)
• Night-time sleep: 10-11 hours
• Total hours of sleep: 10-12 hours

Establish a good sleep routine and follow it consistently.

6-years-old to 12-years-old

• Night-time sleep: 9-11 hours
• Total hours of sleep: 9-11 hours

Continue to follow a well-established sleep routine.

Sleep deprivation can cause havoc to a child's health system, both physical and mental. As a parent, it is your duty to ensure that your little one gets a good night's sleep so that there is no obstacle to his proper brain development.

About the author:

Written by Amrita Gracias on 21 Dec 2018; updated on 26 August 2019

Amrita Gracias holds a degree in English Literature from Stella Maris College, Chennai and a Post Graduate Diploma in Journalism (specialising in Print Media) from the Asian College of Journalism, Chennai. She takes to writing and editing when she isn't answering to the duties of motherhood!

Looking for fun ways to keep your preschooler engaged at home during the pandemic? Check out Little Learners at Home, a home learning programme specifically designed for 3 to 5 year olds by our team of experts.

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