Are you right-brained or left-brained? Actually we are all “whole brained”, yet we draw on unique attributes within each hemisphere depending on our personality and proclivities. In fact, there are dozens of online tests to help you see which way you lean. They distill down to this: if you’re logical, methodical and analytical, you’re left-brained. Creative, artistic and intuitive? You must be right-brain dominant. Some even say that being left-handed is a sign of right brain dominance since the right hemisphere controls the left side of the body. Like many brain myths, this one stems from the wish to make sense of our world and ourselves. And there’s a grain of truth to it.
It’s true that one side of the brain may be used more than the other for certain functions. And clearly, different functions and abilities are affected by damage that affects one side of the brain more. “Split brain” patients demonstrate this very well. As a last ditch effort to control intractable seizures, these patients undergo an operation which severs their corpus callosum, the nerve pathway that connects the two hemispheres and integrates motor, sensory and cognitive functions across the brain. These people, whose hemispheres are essentially disconnected from each other, helped to prove that the right and left hemispheres do indeed have different functions. In fact, with a severed corpus callosum, the two halves of the brain seem to work independently. This is very clearly and dramatically described and demonstrated in this conversation between split-brain researcher Michael Gazzaniga and the actor and Scientific American Frontiers host Alan Alda.
One example of a function that favors a certain hemisphere is language. In most people, language reception and production emanates from the left side of the brain. Another example is facial recognition. The Fusiform Gyrus, a brain region central to recognizing faces is located in the right hemisphere. But in both cases, it’s not that one hemisphere or the other is dominant , it’s just that one of them is relatively better at it. In fact, the left and the right hemispheres share information extensively and communicate with each other constantly.
A 2013 study laid to rest the pernicious myth of left- and right-brained personalities. Researchers at the University of Utah examined MRI brain scans of over 1,000 people and analyzed activity in 7,000 brain regions as well as neural connections within and between these regions. They found that, on average, both sides of the brain were essentially equal in their neural networks and connectivity.
So it’s inaccurate to say that one hemisphere dominates the other or that neural connections in the brain are richer on one side or the other. The two sides of the brain, in fact, are far more similar than they are different. So the next time this myth is raised, use both sides of your brain to refute it!