This is a great question. They say that the brain has 2 sides, because it does have 2 sides! The brain is divided down the middle so we have 2 sides, a right side and a left side. These 2 sides are called hemispheres. The sides are connected through a big bunch of connections called the corpus collosum. The left side of the brain is mostly involved with the right side of the body and the right side of the brain is mostly involved with the left side of the body.
For example, the right side of your brain controls the left side of your body, feels touch from the left side of your body, and gets information from the left side of your vision. The 2 hemispheres of the brain seem to be responsible for slightly different things also. For example, the ability to understand language and to speak is controlled by the left hemisphere (in most people). However, the right side seems to be more involved in processing music. This can be seen when people damage parts of their brain, which can happen from a stroke (where blood vessels in your brain get blocked or ruptured.). Damage to the left side usually leaves the person with problems speaking or understanding language. But, because the right hemisphere may not be damaged, these patients can sometimes sing even if they can’t speak!
Even though we know a lot about what the different sides of the brain do, we actually don’t know a lot about why they are that way. Scientists haven’t really been able to understand why the brain should be organized this way, with 2 sides that are responsible for similar but different things. Like much of science, we have learned a lot about HOW the brain is organized, but we still don’t know much about WHY it is organized that way.
Ph.D. Stanford University
Brain basis of reading and dyslexia
Husband, Nox, kids, Dylan and Chloe
Playing with the dog, reading, walking, brain science, and watching reality TV!
West Middle School Science Club
West Middle School