The human brain is the most complex organ in the body, with the majority of brain development taking place during the first few years of life. Unlike other animals, humans are born at an early developmental stage, which means that the brain must develop rapidly during early childhood to enable the acquisition of vital skills for later life.
The building blocks of the brain are neurons, which are specialised cells that transmit and process information. Dendrites, the branches of the neurons, pick up signals, which are then transmitted through the cell body and along the axon to the synapse. It is the connections between neurons that matter, and there are tens of billions of neurons in the human brain, working together to represent even a simple piece of information.
The triune brain model proposed by neuroscientist Paul D. MacLean suggests that the brain cortex is composed of three parts, with each added during evolutionary stages. The reptilian brain, the first level, controls essential functions for life, including breathing, consciousness, heart rate, and muscle tone. The paleomammalian brain, the second level, includes the limbic system, which supports emotion, behaviour, motivation, long-term memory, and smell. The third and final level is the neocortex, which is responsible for cognitive functions such as language, perception, and spatial reasoning.
The Three Stages of Brain Development in 0-3s
Reptilian brain: The reptilian brain is responsible for basic functions such as breathing, digestion, and heart rate. It also regulates sleep and wake cycles. In infants, this part of the brain is the most developed, and therefore behaviors are mostly focused on survival needs. For example, infants will cry when they are hungry, uncomfortable, or need a diaper change. They will also startle at loud noises or sudden movements, which is a reflex response to potential danger.
Mammalian brain: The mammalian brain is responsible for emotions and social behavior. This part of the brain develops rapidly in the second half of the first year of life. Infants become more aware of their surroundings and start to develop emotional bonds with their caregivers. They start to smile and coo, which is an early form of communication. They also start to become more expressive and show more interest in playing with others.
Human brain: The human brain is responsible for higher-level thinking, reasoning, and problem-solving. This part of the brain continues to develop rapidly throughout the preschool years. Toddlers start to become more independent and assertive, but they still rely heavily on their caregivers for guidance and support. They start to develop a sense of self and their own preferences. They also start to use language more effectively, which allows for more complex communication with others.
Overall, it’s important to note that these three levels of brain development are not mutually exclusive, and they all work together to help infants and toddlers navigate their world.
What Can you Do to Help?
Early experiences and environmental factors play a critical role in shaping brain development. For example, when a baby smells a bad odour, olfactory neurons convert the information into an electrical message that is sent to the brain. The brain then directs the muscles and nerves to react accordingly. With repeated experiences, the neural connections become stronger and more efficient, allowing the baby to learn and adapt to new situations.
In conclusion, the rapid development of the brain during early childhood is crucial for the acquisition of vital skills needed throughout life. Understanding how the brain develops and functions can help parents and caregivers provide an enriching environment that supports healthy brain development.







