It is actually possible! There are many cases around the world where people are living with only half a brain. This ability for people to live with only half a brain is due to a brain phenomenon known as plasticity. Plasticity is the capability of the brain to be modeled by experience. Experiences that we gain throughout our lifetime changes our brain, like modelling clay.
Brain development begins before birth and continues rapidly after. Connections in the brain are created through synapses which allow electrical signals to be transmitted from one area of the brain to another. These synapses are the changes that are responsible for the brain’s plasticity.
Brain development happens through synapses, which are responsible for creating connections. Image obtained via wikimedia commons author US Government.
There are two types of processes that model the brain: experience-expectant plasticity and experience-dependent plasticity.
Experience-expectant plasticity are experiences that every healthy individual expects to gain in their lifetime. For example, vision. With this type of plasticity comes a sensitive time period. If this experience is not met within this limited time period, the window closes and the skill can no longer be developed.
The other type of plasticity is called experience-dependent plasticity. These are neural connections that are created through experience, which can occur throughout the lifetime. These experiences include riding a bike and learning a musical instrument.
The brain’s plasticity can be seen in Michelle Mack, who was born with only the right side of her brain. To compensate for the missing side, the right side of her brain was rewired to take over the functions of the left.
Human brain’s division into the right and left hemispheres. Image obtained via wikimedia commons author Gvdmoort.
Due to the sensitive time period, a child’s brain has a better chance than an adult’s brain to reorganize itself and recover from a brain injury or surgery.
This sensitive period plasticity is demonstrated in a girl in North Carolina named Cameron Mott. At age 3, she was experiencing 10-15 seizures a day due to an inflammation of the right side of her brain. She underwent surgery to remove the inflamed side of her brain which paralyzed the left side of her body. Immediately after the surgery, she was put into intensive therapy to recover the left side. Due to the brain’s plasticity and her young age, the left side of her brain was able to take over the functions of the right side.
A segment called Today’s Health on the Today Show interviewed Cameron Mott and her family about Cameron’s extraordinary condition:
The Today Show’s segment, YouTube video from username ichoosepeople.
Scientists used to believe that the brain was hard-wired and could not undergo changes once the brain was developed. There was the belief that children with only one side of their brain would not be able to live but these real cases have shown the brain’s capability to change known as plasticity.
– Christine Wong
