The human brain is split into two different hemispheres: the right hemisphere and the left hemisphere. While the brain is split down the middle into two equal hemispheres, many people believe that the left side of the brain is more logical and deals with analytical and intellectual situations, while the right side of the brain deals with creativity and emotions. While this notion is widely accepted by people throughout the world, it is not fully understood.

The history of symmetry in the brain has not been fully studied yet, however, scientists believe that an evolutionary advantage has allowed specific brain functions to be compact on one side of the brain, and other related functions to be compact on the other side of the brain. This reduced the likelihood of transmission errors in the brain. Evolutionary advantage means that throughout many years, the organisms with the most efficient brain function have survived, while others may have died. This has allowed these specific genes to be passed down and survive.

Handedness is a very clear example of brain lateralization (one side being more dominant than the other), with most people (90%) being right-handed and the remaining 10% being left-handed or ambidextrous. Within the brain, language is another example of brain asymmetry.  Scientists have discovered that the left side of the brain deals with the ability to speak as well as the ability to understand language. Understanding the different hemispheres of the brain and their functions is crucial, because it can allow doctors and scientists to help and regulate people with brain injuries. For instance, aggression, self-awareness, attitudes, beliefs, and intense emotions can be affected after a person has a brain injury. Understanding the brain hemispheres can be helpful in monitoring and controlling unusual behaviors caused by brain injuries.

While brain lateralization is true for some aspects, the hemispheres of the brain are not truly separate and rely on communication between them. Communication between these hemispheres is possible by commissural fibers where a constant traffic of neural messages is passing. The corpus callosum is the most prominent of these tracts that allows communication. While some basic functions can be drawn to a certain hemisphere, more complicated actions are explained in networks across the brain and require the communication of both hemispheres. For instance, production and response of music is known to come from right hemisphere function. However, processing pitch, tempo, and melody has aspects that are regulated by the left side of the brain. So, musicians use both sides of their brains to work together.

It is believed that the right side of the brain is only concerned with creativity. However, this simple explanation does not fully describe how creativity works and is processed in the brain. Different types of creativity actually require different parts of the brain. For instance, the ability to make up stories relies on the left side of the brain while moments of epiphany are attributed to the right hemisphere. The hemispheres work together to allow creativity.

While it is believed by many people that the right and left sides of the brain have completely different functions in our lives, the truth is that communication between brain networks is necessary to complete functions. This blog post is supposed to give a basic overview of the brain hemispheres (and clear up any confusion for people that didn’t have much knowledge about it), however, I can make a more in depth post if people are interested!