Neuroscience research has shown us that early childhood is a time of tremendous brain development. The young brain literally changes shape and size in response to everything encountered in this early period of development. New environment, life experiences, caretakers and relationships can all affect the way complex brain circuits are wired.
Find out how to help your child’s brain develop optimally.
Table of Contents
- Brain Development in Children
- Nature Vs Nurture in child development
- When Does a Fetus Develop a Brain
Children Brain Development
How Many Brain Cells Does a Child Have
An infant’s brain at birth has roughly 86 billion neurons1, almost all the neurons the human brain will ever have2.
Although a newborn has about the same number of neurons as an adult, it has only 25% of the adult size.
That’s because infant’s neurons are connected by only roughly 50 trillion neural connections, called synapses, whereas an adult brain has about 500 trillion of them3.
This network of synaptic connections will ultimately determine the development of behavior and cognitive functions.
What Is Synaptic Pruning in Early Brain Development
The network of synapses grows rapidly during the first year and continues to do so during toddlerhood. Childhood brain development is fast.
By age 3, the synaptic connections have grown to 1000 trillion.
But not all of the synapses will remain as the child’s brain grows.
Life experience will activate certain neurons, create new connections between neurons and strengthen existing connections, called myelination.
Unused connections will eventually be eliminated. This is called synaptic pruning4.
Synaptic pruning is the neuronal process in which unused neurons and neural connections are eliminated to increase efficiency in neuronal transmissions.
Building massive connections, creating and strengthening them through life experiences and pruning unused ones is a remarkable characteristic of human brains.
This experience-based plasticity allows babies to adapt flexibly to any environment they’re born into without the constraint of too many hardwired neural connections5.
The Use It Or Lose It Brain Sculpting Property
The benefits of developing a baby’s brain this way are enormous, but so are the costs and the risks6.
First, children require a lot of care and relevant life experiences before they can be independent.
Second, what parents do or don’t do during the formative years can have a profound impact on the child’s mental health and physical health.
Here’s a synaptic pruning example. Let’s say a parent consistently shows a toddler love and care, then the “quality-experience connections” will develop or strengthen over time. But if the parent constantly punishes or is harsh to the child, then the “adverse-experiences connections” will be stronger instead. And because the quality experience is missing, those corresponding brain cells will wither and eventually be removed from the child’s brain circuits. As a result, the child grows up lacking the love-and-care understanding that is essential to create healthy, meaningful relationships in his future life7.
Why The Early Years Matter in Human Brain Development
Childhood is a time of tremendous sensitivity, a time when experience bestows lasting effects8.
Although this experience-based brain plasticity is present throughout one’s life, a child’s brain is a lot more plastic than a mature one.
Brain cell pruning occurs most rapidly during a child’s preschool years. During adulthood, the density of these connections will be half that of a toddler at age two.
This is why nurturing and positive parenting are so important. Things can go seriously wrong for kids deprived of basic social and emotional nurturing during the developmental process.
Critical Periods and Sensitive Periods in the Developing Brain
Within early childhood, there are windows of time when different regions of the brain become relatively more sensitive to life experiences.
These periods of time are called critical periods or sensitive periods.
During a critical period, synaptic connections in those brain regions are more plastic and malleable. Connections are formed or strengthened given the appropriate childhood experiences. After the critical period has passed, the synapses become stabilized and a lot less plastic.
For example, a young child can learn a new language and attain proficiency more easily before puberty. So the sensitive period for language development is from birth to before puberty.
Another example is emotional regulation. Emotional self-regulation forms the foundation of the brain architecture. It’s a person’s ability to monitor and regulate emotions. Emotional regulation is strongly linked to the development of social skills9, future learning and success in school10.
Emotion regulation is not a skill we’re born with. Yet it’s an essential skill in a child’s healthy development11.
The sensitive period of learning this crucial life skill is before a child turns two. Children who suffer from early trauma such as child neglect or abuse have difficulty learning self-regulation12. Critical or sensitive period is another reason why early life experiences matter so much.
Nature vs Nurture In Child Development
Besides influencing development of brain architecture, early life experience has another significant impact on a child’s development.
A large amount of scientific evidence indicates that life experience can affect gene expression — how information in a gene is used (epigenetics) — in some cases by slowing or shutting the genes off, and in others by increasing their output13.
This is why identical twins are not carbon copies of each other.
Although their genes (DNA code) are identical, their epigenetic markers are different from birth and continue to diverge as they interact with the environment in distinctive ways.
Even more important, these epigenetic changes can be permanent and passed down from generation to generation.
In the age-old nature-versus-nurture debate, epigenetics offers a surprising middle ground.
Genes are profoundly important, but so are environmental factors.
When Does a Fetus Develop a Healthy Brain
Neuron production in the fetus begins in week 3 post-conception during the embryonic period.
As neurons are produced, they migrate to different brain areas to form rudimentary structures of the developing brain, central nervous system, and peripheral nervous system.
This is a period of rapid neurological development and brain growth to create cortical and subcortical structures.
When Does Your Brain Stop Developing
So, at what age is a child’s brain fully developed?
On average, the brain is fully developed by age 25. Although an individual’s brain growth trajectory can vary slightly, most people’s healthy brain development is complete in their mid-20s.
The prefrontal cortex is the last brain region to develop.
However, it doesn’t mean the brain stops changing.
Forming and changing interconnections in our brain is an ongoing process that takes places throughout our lives. But as we age, they do so at a much slower rate.
The Importance Of Neurological And Brain Development In Early Years
Neuroplasticity and epigenesis are two major cornerstones in understanding a child’s neurological and brain development in the early years.
While we don’t need to be perfect parents (and who can be?), good enough parenting can do a child tremendous good.
In particular, among the different parenting styles, authoritative parenting is the best parenting style associated with the best outcome. Adverse childhood experiences, on the other hand, can lead to a devastating consequence.
Early childhood education is also important to a child’s cognitive growth. Finding good childhood care providers and choosing a quality preschool for your child can benefit their development in the long term.
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