Neuroscientists from the University of Utah have debunked the myth that our personalities are dominated either by our left or right hemispheres of our brain, as according to Science Daily, no strong evidence exists to uphold the distinction between left-brained and right-brained individuals.
"Right-brained" people are often thought to be more creative, thoughtful, emotional and imaginative, while "left-brained" individuals are thought to be more logical, analytical, objective, better with language and mathematical. Whichever side is more "dominant" is thought to be reflected in a person's cognition and personality.
However, over the course of their two-year study, Utah researchers discovered that despite long-held assumptions in popular culture, people have no preferential left or right-brained relationship, as we use both hemispheres equally, and neither side is particularly "stronger" in healthy individuals.
"It's absolutely true that some brain functions occur in one or the other side of the brain," explained Jeff Anderson, M.D., Ph.D., lead author of the study. "Language tends to be on the left, attention more on the right. But people don't tend to have a stronger left- or right-sided brain network. It seems to be determined more connection by connection."
While certain mental processes are specialized in either the right or left hemisphere, researchers used brain imaging to debunk the popular left vs. right-brained theory.
The scientists analyzed resting brain scans of 1,011 people between the ages of seven and 29 over the course of the study, analyzing the functional lateralization of the brain, measured for thousands of brain regions (the neuroscientists broke them up into about 7,000 regions), in each individual, and found no evidence to suggest that one side is more dominant than the other. The brain scans they analyzed were from a database called INDI, the International Neuroimaging Data-Sharing Initiative.
Participants' brain scans were taken during a functional connectivity MRI analysis, in which individuals laid in a scanner for 5 to 10 minutes while their resting brain was analyzed.
Jared Nielsen, a graduate student in neuroscience who carried out the study as part of his coursework, explained that of if "you have a connection that is strongly left- lateralized, it relates to other strongly lateralized connection only if both sets of connections have a brain region in common."
So patterns in the networks of each hemisphere exist, but one hemisphere is not more "connected" or "wired" than the other.
"Everyone should understand the personality types associated with the terminology 'left-brained' and 'right-brained' and how they relate to him or her personally," Nielson said to Science Daily. "However, we just don't see patterns where the whole left-brain network is more connected or the whole right-brain network is more connected in some people. It may be that personality types have nothing to do with one hemisphere being more active, stronger, or more connected."
The University of Utah study is entitled "An Evaluation of the Left-Brain vs. Right-Brain Hypothesis with Resting State Functional Connectivity Magnetic Resonance Imaging," and was published this month in the journal PLOS ONE.
Click here to see a photo of some of the resting brain scans that were analyzed in the study, and click here to view the full study.
*This article has been edited to note a change.
