Through decades of research, neuroscientists have shown that the experiences children get today can affect their brains for life. The reason: during the early years of life (0 – 3), the brain not only grows physically faster, but it is also far more receptive to external influences than it will ever be in adulthood.
The basis of brain development
Brain formation begins from the first few weeks after conception, with the shape of the neural plate and, later on, the neural tube. The brain continues to grow all through pregnancy, at birth, Your Child’s brain is about a quarter of the size of an adult brain. It doubles in size by the end of the first year, and by the third year, the brain is about 80% of adult size.
The brain continues to grow till adulthood, but much of the growth has occurred by age 5. Your Child has all the neurons (brain cells) the little one will ever have in life at birth. So, neuronal connections (synapses) form the basis of brain development going forward.
What neuroscience has shown about brain development
We now know a lot of facts about brain development, thanks to the decades of neuroscience research. Here are the things we know so far:
The brain has up to twice as many synapses in the first three years as it will have in adulthood
Millions of neural connections are formed every second during the first three years of Your Child’s life. This rapid proliferation of synapses creates more synapses than Your Child’s brain needs. Between ages 2 and 3, the brain has up to twice as many synapses as it will have in adulthood.
The unused connections are pruned during late childhood and adolescence, as the early simple brain circuits give way for more complex circuits.
The construction of Your Child’s brain is affected by early experiences
Because Your Child’s brain creates too many synapses in the first three years, the brain is exceptionally responsive to external input. At this time, the brain can “capture” experience more efficiently than it can ever do later when the excess synapses are pruned off. Capturing the external stimulus (experience) helps the brain develop the centers (such as visual, hearing, and motor centers) that coordinate responses to such stimuli.
As those centers become more complex and efficient, some simple, early synapses are weeded off. The ability of the brain to rewire itself – also known as plasticity – helps humans adapt more readily and more quickly to changing environments. Hence, the process of pruning is an efficient way for the brain to achieve optimal development.
Your Child’s developing brain is shaped by the combination of genetic expressions and early experiences
So why would the brain make more synapses than it needs and later discard the extra ones? The answer is that brain development is a product of the interplay between genetic and environmental factors. While the genes provide a blueprint for the brain, Your Child’s environment and experiences determine how the genes are expressed. In other words, the genes allow the brain to fine-tune itself according to the input it receives from the environment.
The input from the environment, which neuroscientists now believe is a critical factor in brain development, comes from the “serve and return” relationship between the child and their parents and other people. Your Child naturally tries to interact with you or the people around through babbling, facial expressions, and gestures (which researchers often call the serve). You should gesture back to the little one and respond with the same kind of vocalizing (the so-called return).
Without such responses — or if the answers are unreliable or inappropriate — Your Child’s brain architecture will likely not form as expected. This can lead to disparities in learning and behavior.
The brain’s capacity for change decreases with age
Your Child’s brain is most flexible (plastic) early in life to accommodate a wide range of environmental inputs and interactions. But as the brain matures, the various centers get more specialized to assume more complex functions. As a result, it becomes less capable of reorganizing and adapting to new or unexpected challenges.
The phenomenon is known as early plasticity. It simply means that it’s easier and more effective to influence a baby’s developing brain architecture than to rewire parts of its circuitry in the adult years.
By the first year, the parts of the brain that interpret sounds are becoming accustomed to the language the baby has been exposed to. In addition, the brain is already starting to lose the ability to recognize different sounds found in other languages. While it’s still possible to learn other languages, it becomes increasingly difficult (requiring conscious efforts) over time, as the brain circuit that controls language becomes more specialized.
Cognitive, emotional, and social capacities seem all intertwined
The brain is a very complex organ with multiple functions, which operate in a highly coordinated fashion. An individual’s cognitive abilities appear to be linked to emotional intelligence and social competence. These three, together, form the bedrock of mental wellbeing.
Your Child’s emotional and physical health, social skills, and cognitive-linguistic capacities, which are majorly determined by how well the brain developed in the early years, are all important prerequisites for success in school and, later, in the workplace and community.
Toxic stress can damage the brain, but positive stress can aid its development
Toxic stress is a strong, unrelieved stimulation of the body’s stress management system, often caused by repeated abuse, neglect, severe maternal depression, or other factors that cause trauma for the mother (indirect stress) or the child (direct stress). It is now clear that chronic, unrelenting stress in early childhood can be toxic to the developing brain. Children may experience toxic stress if they are repeatedly left alone without an explanation.
While toxic stress is dangerous for the developing brain, positive stress is an important and necessary aspect of healthy development.
Positive stress is a moderate, short-lived physiological response to uncomfortable experiences within a secure setting – a child may experience such stress when it learns how to walk within the safety of your presents.
Support Your Child’s brain to develop optimally
A child’s brain will develop the best if they grow up in an environment that is rich in positive social interactions and is fed with nutritious food. A healthy environment is one that protects children from any sources of toxic stress which can affect the developing brain for life and lead to problems in learning, behavior, and mental and physical health later in life.
Dr. Prapasri Nuntnarumit (Developmental psychologist) (31 March 2021)