This post will look at how neural networks are created, grow and are strengthened. In essence this is the biological process of learning.
In a previous post on Emotions and Learning, we identified that neural networks are used to carry information from the body into the brain and between different areas of the brain.
First a little about our brain: The human brain weighs approximately 3 pounds (1.4kgs) and is about the size of a grapefruit. It is made up of 78% water, 10% fat and 8% protein. It uses around 20% of our body’s energy and oxygen and receives 8 gallons (30 liters) of blood per hour. It is soft and spongy and can be easily cut with a butter knife. The brain is divided into different regions that perform different functions. As an example, a previous post on Emotions and Learning discussed the function of the limbic system in relation to processing emotions and the functions of the cerebral cortex in general.
There are two kinds of brain cells, the glia and the neuron. Glia make up 90% of the total and their function, apart from proving a gluing function is not well known. Neurons make up the remainder and there are approximately 100 billion neurons in the human brain. They are made up of the cell body (soma), dendrites and axons. Dendrites are parts of the neuron that receives information. They form tree-like structures as they are attached to other neurons. Axons are responsible for sending information to other neurons.
Information is carried inside neurons and is passed from one cell to another across the gap between neurons called the synaptic gap using chemicals created within the soma. These chemicals are called neurotransmitters.
The growth of neural networks
From as early as four weeks after conception, the human embryo begins creating neurons at the rate of half a million every minute. The neurons soon begin to reach out to each other, establishing points of contact called synapses. By the end of pregnancy, points of contact between neurons are being made at the rate of 2 million per second.
Before birth, neural networks are partly created in response to what the embryo is experiencing in the mother’s womb, including the physical sensations of touch, sound and taste. Then, from the moment of birth, babies start to absorb everything that comes through their senses.
The strengthening of neural networks
In babies, neural circuits that receive repeated stimulation through the senses develop stronger synaptic connections, while those that do not begin to lose strength. In the same way with adults, our neural networks are made stronger through repeated learning.
The video below demonstrates how this process happens: