New research challenges the long-held notion that people are either right-brained or left-brained.
In the journal PLoS ONE, researchers from the University of Utah are saying that contrary to prior research suggesting that humans use one side of their brains more than the other – e.g., those who use the left side more are better at logic and math and analytical thinking, and those who use the right side more tend to be creative thinkers – and that this helps determine our personality types, this theory appears to be myth.
Two-year study of more than 100,000 people
The researchers used brain imaging to make their point, carrying out a two-year study of more than 100,000 people between 7 and 29 years old participating in the International Neuroimaging Data-Sharing Initiative (INDI).
First, the functional lateralization of their brains was measured, meaning the specific mental processes taking place in each hemisphere while patients laid motionless in an MRI scanner for up to 10 minutes.
No indications of one side being used more than the other
After dividing the brain into 7,000 regions and determining which ones weighed towards functional lateralization, investigators say they could ascertain no indications that one side of the brain was being used more than the other, or 'preferentially.'
Said lead author Dr. Jeff Anderson:
It is absolutely true that some brain functions occur in one or the other side of the brain. 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.
Added co-author and neuroscience graduate student Jared Nielsen:
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 … Everyone should understand the personality types associated with the terminology 'left-brained' and 'right-brained' and how they relate to him or her personally. However, we just do not 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 results are controversial and stirring up debate in the neuroscience community.