“If only I had a brain,” the scarecrow sang in the Wizard of Oz. The scarecrow is my favorite character in the movie. What he discovers is that he does have a brain and he is thinking.
We, like the scarecrow, need to discover our own brain. Brain cell development starts at 42 days after conception. The first brain cell called a neuron fires. Approximately 9,500 new neurons are created every second till there are 100 billion neurons. We are born with 100 billion neurons and have that many till late middle life.
Sixty days before your birth your neurons start trying to communicate with each other. That communication is a reaching out as a strand called an axon. When a connection is made, a synapse is formed. By the age of three, each of the 100 billion neurons have formed 15,000 synaptic connections. That’s 15,000 for each of your 100 billion neurons. It is estimated it would take 32 million years to count all the synaptic connections in the human brain at a counting rate of one synapse per second. Our neuronal connections are 10 followed by 1 million zeroes. To put that in perspective, the known particles of the universe are 10 followed by 79 zeroes.
An example of the brain development is shown by 16 months to 36 months when there is a big burst of language and cognitive competence. The child goes from knowing a total of 5-10 words to gaining 1-2 words every day. The stronger the neuron connection, the faster the processing. We learn because our neurons are connected. Each time we learn something new, our brains are changed. As the saying goes neurons that fire together are wired together. The patterns of woven connections is extensive, intricate and unique to each brain.
The brain’s primary task is to maintain the body in a optimal state relative to the environment for survival. The brain receives a constant stream of information as electrical impulses from neurons in our sensing organs. The hierarchy of processing is determined by whether the information warrants attention. If it is new or important information, the brain amplifies the signals, causing them to be represented in various regions. If the activity is sustained long enough, it results in a conscious experience. Taken further, the brain instructs the body to act by sending signals to the muscles to make them contract.
The Three-Brain System
All brain theories, of course, are oversimplifications. But they can serve as useful metaphors for helping us think about the complex organism of the brain in practical, concrete ways. Dave Meier in The Accelerated Learning Handbook says “Brain research is a fast-moving science, and new discoveries are overturning old ones every day. So don’t take any description functioning (including this one) as absolute.”
The Reptilian Brain The Reptilian brain is the most basic, or primitive, part of the brain, located at the base of our brain. It is the same core brain that modern reptiles possess. Birds and mammals also have this same core reptilian brain. This part is the information gatherer for our senses — sight, touch, pain, balance, and temperature. It keeps your heart beating, knows when it’s time to eat, and even contains the most primitive emotion: fear. Fear is the essential instinct, the fight or flight response that is built into all animals for survival.
The Neocortex The neocortex is the most recent part of the brain to develop, accounting for 80% of the human brain. It is responsible for higher-level thinking. Included in all the gray folds of our brain are language, symbolism, abstraction, analysis, and deduction. It is what makes us human.
The Limbric Brain The midbrain between the reptilian brain and neocortex is called the limbric brain. The system is a collection of processors and hormone controllers that govern memory and emotions. It’s the social and emotional brain. The limbic system enable us to care. It is what allows us to be in groups, bond with our mates, and nurture our young.
The limbic system enables us to form close relationships with family and friends. The emotionally charged experiences that we share with others gets deeply embedded into our responses over time. Then, we have a context to evaluate what appropriate behavior looks like, how we like to be treated, and how to form close relationships.
These remembered experiences help us to learn how to care for others. Our favorite song was written in the songwriter’s neocortex. We are moved by the song because of our limbic system. The amygdala and hippocampus are two key regions of our limbic system. The amygdala is dedicated to processing our emotions and those of other people. The hippocampus is essential in the formation of long-term memories. Together, the amygdala and the hippocampus help us form long-term emotional connections with people. The more emotionally charged an experience is, the more intense it feels in our amygdala, which helps the hippocampus to remember the experience long term. Our most emotional memories are the most vivid ones. That is why they are remembered more easily than facts.