Brain plasticity: Healing and growth in the adult brain
Brain plasticity means that the brain is able to change in order to adapt to new experiences. It does this by changing the number and connections of the cells in the brain. Neurons can grow and die. They have processes that reach out and connect to other neurons in order to communicate. The connections are known as synapses. Neurons can change the number of synapses they have with other different neurons and the pathways made by these connections determine the way our brain works.
Until recently, it was thought that the ability of brain cells to grow and change stopped at adulthood. However, now it is known that brain plasticity occurs throughout one’s lifetime. It occurs during development when the immature brain of a baby or small child learns the necessary skills to become and adult. It also occurs in adult life when we learn something new or are exposed to a new experience. Importantly, it also occurs when a part of the brain is damaged.
The environment plays a large part in the development of brain plasticity. The more varied our environment is, the more malleable the neuronal connections become, in order to adapt to the changing environment. A baby’s brain is flooded with sensory information such as the smile on its mother’s face, the sound of her voice, the feel of her loving touch. In order to make sense of all this information, the neurons in the brain must connect with each other. The neurons from the eyes connect with those in the visual area in the brain, which in turn connect with those in the motor area, so that the baby can cry out when it sees its mother’s face.
In adulthood, brain plasticity plays a large role in learning and memory. Whenever we learn something new, like a new language or riding a bicycle, new synapses are formed. The more we practice, more synapses are formed and the connections become stronger. Practice and recall strengthens the connections, while disuse can cause synapses to be lost. When this happens, human skills become rusty or can become lost altogether.
It is well known that different parts of the brain serve different functions. There is a motor area, a visual area, a speech area and a sensory area. The entire brain can be mapped by its function, one part for memory and emotions, another part specific for movement of the tongue or fingers. However, people who have part of the brain damaged, either by stroke or removed by surgery, can regain the function of the part of the brain that was damaged. By studying the brains of these people, scientists have discovered that this is achieved by brain plasticity. The neurons in a different part of the brain can take on the function of those in the damaged part of the brain. However, this is only possible with learning and practice. Those with a damaged part of the brain need to relearn the skills that that part of the brain were responsible for. Relearning and practice enables the neurons in the functioning parts of the brain to make the connections that were previously found in the damaged part of the brain.