As a former elementary school teacher and now mother of four young children, I have always been fascinated by the brain and how it works. One of the most interesting things I’ve learned and observed with my own children is the how capable they are of learning at a very very young age with just little nudges in the right direction when they are ready (i.e. teaching in the zone of proximal development).
We often think of children being ready to “learn” when they are old enough for formal schooling, but by the time children are old enough for kindergarten, the frameworks of their brains are pretty much set for life. The crucial window of brain development begins at about 6 months and peaks at 2-3 years of age. I think this is a window that is largely ignored, but if can recognize its importance and provide stimulating experiences during this golden opportunity of time, we can help our children to develop their best brains.
Before we start getting into some of the nitty gritty about how the brain works, I wanted to point out what happens at the other end of the spectrum when it doesn’t work. In this example, you’ll see what happens to childrens’ brains when they are ignored, neglected, abandoned, and mistreated.
In his NPR article, “Orphans’ Lonely Beginnings Reveal How Parents Shape A Child’s Brain“, Jon Hamilton explains how when the corrupt Romanian government was overthrown in 1989, the world was shocked to learn about the more than 100,000 children in government care that were left alone in their cribs, wallowing in their own filth, and with nothing but the white ceiling to stare at and the cries of the other babies to keep them company…for days and days and days. There was no one there to soothe their cries, no one there to hold them and give them affection, and no one there to talk to them and help them to interact with their environment. The result was stunted growth and a range of social and emotional problems.
The odd behaviors, language delays, and range of other symptoms suggested problems with brain development, and so researchers began studying the children using a technology known as electroencephalography (EEG), which measures electrical activity in the brain. What they found were disturbingly low levels of brain activity. As the children grew, there were able to conduct MRIs on them, and it showed that their brains were actually smaller and that they had a reduction in grey and white matter. (The grey matter is near the outer part of the brain and is mostly all of the neurons bunched together. The white matter is on the inner part of the brain and is mostly the myelinated axons that connect the neurons together.)
In another experiment conducted after the orphaned children had been adopted, it showed that their brains could not discriminate the face of a stranger from the face of their adoptive mother. Because their brains were not able to identify with a loving caregiver at a young age, that part of their brain wasn’t developed, and then when someone was ready to give them love, they didn’t know how to accept it. This is called reactive detachment disorder, and with lots of patience and love, it is possible to rewire the brain, unfortunately it’s just not very probable. Today, the system in Romania is still corrupt, and there are currently 70,000 children waiting for adoption. 🙁
How the Brain Works
Okay, so now that we’ve established that the environment is a crucial factor in brain development, let’s take a look at why that it. I love this video clip below because it shows how the brain is an interconnected web of not just the neurons, but the connections (synapses) that are between them.
When you look at an individual neuron, you’ll notice that it’s made up of three main parts.
- Cell Body: This is the main part of the neuron, It’s where the nucleus is and it directs all activities. This is what makes up most of the gray matter in the brain.
- Dendrites: These short fibers sticking out of the cell body receive messages from other neurons. If you were to zoom in close to look at the tip of a dendrite, you would see that it never actually touches another neuron, but connects via a synapse (more on this in a minute).
- Axon: This long single fiber carries messages away from the cell body to other cells. It might send a message to a nearby neuron or to a far away muscle fiber. Axons that are used over and over get coated with a myelin sheath which helps messages to transmit faster and is what makes up the white matter in the brain (more on this in a minute too).
Synapses are Where It’s At
Neurons on their own can’t really do much, but when they are connected, that is what creates brain activity. When neurons connect, they actually don’t ever touch each other, but instead communicate across a gap called a synapse. One single neuron can have anywhere from hundreds to thousands of synapses.
How Synapses Work:
- First, A neuron fires an electrochemical signal from its cell body that travels through the axon and out to the tip of the dendrites.
- From here, neurotransmitters cross the synaptic cleft and are met with receptors on the other side that welcome it to the next neuron.
- This happens from one neuron to the next in a sort of a domino effect.
Synapses As We Age
We are born with about 100 billion neurons, which is pretty much the same number of the neurons the brain will ever have. The number of synapses, however, is a number that does change over time. In the first decade of life, a child’s brain can form trillions of synapses. The number of synapses peaks at about 2-3 years of age. (source)
When children are born, they have about 2,500 synapses per neuron and by age 2 or 3, they can have about 15,000 synapses! (source) From the time a child is about 6 months old until they are about 2-3 years of age, there is a SYNAPTIC EXPLOSION!!! Because children are not very mobile or explicitly expressive about what they are learning and what they need in addition to the fact that parents are often overwhelmed with sleep issues, teething, and other parenting concerns (With four children 5 and under, I am WELL aware of this! :), I feel like the importance of this learning period is often overlooked and undervalued.
There are an ENORMOUS amount of connections that are being formed at 6 months and 2 years of age. Click here to see a really cool chart showing the synaptic explosion happening between 6 months and 2 years.
Experiences Make Neural Connections
Genes provide the basic framework in the brain, but experiences determine which neurons are used and which pathways are formed and strengthened. When children are very young, their brains are very “plastic” (malleable), meaning that they are easily able to learn something new through experience, but this changes over time and the brain becomes less “plastic” and it becomes more challenging to learn something new from experience.
Click here to see a really cool graph that shows how when we are 2, experiences are easily able to shape the brain, but the ease with which this happens declines with age. When we reach our 20s, we’re kind of at an even plateau, and then as we age from there it gets progressively harder for the brain to change from experiences.
The reason why it’s easier to learn something new at a young age is because the brain is like a blank slate. This tabula rasa allows for children to shape their brains about their environment and experiences, but as we age and our brains become more established, learning something new requires rerouting the information through existing pathways rather than simply creating new ones.
Myelination Speeds Up Connections
It wasn’t until fairly recently that we realized the true importance of myelination. Myelination can be seen as the white matter in the brain and is comprised mostly of the fatty substance called myelin that coats the axons. This myelin sheath is made out of schwann cells that over time and with continued use wrap around the axon like a spiral. (Check out a cool video here to see this in action.)
The myelin sheath serves two functions:
- It protects the axon so that it doesn’t lose the electrical impulse.
- It increases the speed at which the electrical impulse travels. In an unmyelinated axon, the electrical impulse travels in a wave, but in a myelinated axon, the electrical impulse sorts of hops through it.
The first time a child tries to walk, the pathway hasn’t been myelinated yet, so he only takes a few shaky steps and then falls down. But over a long period of time and lots and lots and lots of repetition, he will take two steps, and then three, and before you know it, he’ll be running everywhere! The pathway that controls walking becomes myelinated so that he doesn’t even need to think about it anymore, it just happens. It’s why they say, “You only need to learn how to ride a bike once.”
Whatever experiences a child has over and over and over again will determine which pathways will become myelinated. The myelinated pathways are the ones that will remain, the rest will become pruned away.
Much like a painter likes to work with more paint than is needed for the job and a builder likes to construct with more materials than is needed for the project, a child’s brain is provided with far more neurons and synapses than are functionally needed and/or preferred. Synaptic pruning is the process by which these extra neurons and synapses are eliminated. This is what increases the overall efficiency of the neural network.
The entire process begins to happen at a significant and rapid rate when a child is approximately 3 years old. By the time, a child is 10, most of the synaptic pruning has occurred. In fact, when a child is 10, 50% of the synapses that were present at 2 years of age have been eliminated.
We talked about the synaptic explosion earlier, but now let’s take a look at what happens when the synapses are pruned. (Click here to see a graph that I wish I could include, if only it were on Wikimedia Commons!) When you look at the brain of a 2 year old, it kind of looks like a jumbled mess compared to the brain of a 4 year old. In the 4 year old’s brain, there is more organization and cohesion. The neurons that exist and the pathways that have been used over and over again to connect them are making the brain more efficient. This continues to be more obvious in the 6 year old’s brain.
By the time a child is 10, the framework for the brain is pretty much set, and the brain continues to focus on specialization. The adult brain is similar to the 6 year old’s brain but with fewer, yet stronger, neurons and connections. (Click here to see another image I wish that I could include!)
In one of my education classes, my professor explained it by saying that the brain is like a giant house with hundreds of rooms. Whatever rooms the child goes into over and over and over again, those are the rooms that will remain, and the rooms that are unused will become closed off and die.
So what rooms does your child want to go into over and over again? What experiences and opportunities will you help to provide repetitiously? I believe that every child is different and that every child’s brain should be given the freedom and opportunity to develop as it is meant to. For me as a parent, that means that I provide multiple opportunities for all of my children to achieve this goal.
This “use it or lose it” concept is fascinating because it gives so much more meaning to the younger formative years as the brain is forming. People assume that because little babies aren’t physically able to engage with their environment, that they are not mentally capable of it. But that’s just not true. Before babies start talking, they are immersed in language and exposed to it over and over and over again. Their brains are busy forming pathways before they even speak!
In this way, each child’s brain becomes specifically wired to adapt best to the environment that he or she is in. If the child is to grow up in a stimulating environment with lots of learning possibilities, then they need a brain that is primed and ready to thrive in that type of environment.
I think that by just being aware of how the brain functions, it can help us to better understand what is going on in the minds of our children. By providing a loving, nurturing, and stimulating environment full of lots of learning opportunities, we can help our children to develop their best possible brain.
To see how to put this information about the brain into practice, check out some of my other articles:
- Oral Language Development: More Important Than You Think
- How to Engage Your Baby with Reading
- How to Raise Children Who WANT to Read
- How Children Really Learn to Read
- The Importance of Creative and Imaginative Play
- How to Create an Environment That Encourages Independence, Creativity, and Learning
Resources for Further Research
Throughout this article, I’ve linked to my resources where appropriate, but I also read the following articles and watched the following videos that helped me to get a broad understanding of this topic. If you’d like to learn more about this topic, I highly recommend checking out some of these videos and articles.
- How the Brain Works – A 9 minute video by MsThinkology that does a wonderful job of explaining how the brain works.
- Neurons and How They Work – A great 5 minute video by the Discovery Channel with great images that show how neurons work in the brain.
- Neurons, Synapses, Action Potentials, and Neurotransmission – This article by Robert Stufflebeam from the Consortium on Cognitive Science Instruction thoroughly explains how the brain works using language that is complex, but easy to follow with excellent graphics.
- Nurturing the Developing Brain in Early Childhood – This PowerPoint by Lisa Freund, Ph.D. from The National Institutes of Health in Maryland really sums up everything I’ve talked about in this article.
- Baby’s Brain Begins Now: Conception to Age 3 – This article by the Urban Child Institute goes into more scientific depth about why children are primed and ready to learn before the age of 3.
- Children and Brain Development: What We Know About How Children Learn – This article by prepared by Judith Graham, Extension human development specialist, and revised by Leslie A. Forstadt, Ph.D. Child and Family Development Specialist through the University of Maine offers a succinct explanation of how the brain works and provides lots of specific things that parents can do to help their children’s brain development.
- Brain Plasticity and Behaviour in the Developing Brain – This scientific article by Bryan Kolb, PhD and Robbin Gibb, PhD published in the US National Library of Medicine National Institutes of Health goes into thorough detail about the plasticity of the developing brain and discusses all factors that affect it.
- Why Practice Actually Makes Perfect: How to Rewire Your Brain for Better Performance – I really like this blog by Jason Shen because he does a wonderful job of explaining the importance of myelination.