Left Vs. Right: University Says Neither When It Comes To Brain Dominance
August 19, 2013

Left Vs. Right: University Says Neither When It Comes To Brain Dominance

Brett Smith for redOrbit.com - Your Universe Online

The idea of a “left-brain” versus a “right-brain” personality has been used in a variety of contexts over the years, from interpersonal relationships to career choices. However, a new study from the University of Utah found that the idea of a dominant side of the brain affecting personality could be nonsense.

Using brain imaging scans taken from over 1,000 volunteers, the Utah neuroscientists found that each side of the brain has specialized functions, but there is no such thing as a dominant side – according to their report, published in the journal PLoS ONE.

"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,” said Dr. Jeff Anderson, lead author of the study. “But people don't tend to have a stronger left- or right-sided brain network. It seems to be determined more, connection by connection."

In the two-year study, the neuroscientists examined brain scan images of volunteers in the International Neuroimaging Data-Sharing Initiative (INDI) who were between the ages of seven and 29. First, scans were taken using magnetic resonance imaging (MRI) analyses while the participants were lying in the scanner, providing "resting" brain measurements and allowing researchers to look at brain activity in one area of the brain and compare it with activity in another area.

The team then sectioned the brain into 7,000 regions and determined which areas showed evidence of specific mental processes on either the left or the right side of the brain. They also looked at connections within the brain and how combinations of the brain regions left-lateralized or right-lateralized.

The Utah scientists found that connections within the brain are specific to one side, ‘left-lateralized’ or ‘right lateralized’, but did not see evidence of one side being more prevalent than the other.

According to co-author Jared Nielsen, the new study could change the way people think about left-brained or right-brained with respect to personality.

"Everyone should understand the personality types associated with the terminology 'left-brained' and 'right-brained' and how they relate to him or her personally," he said. "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,” Nielsen added.

Both ‘left-brained’ and ‘right-brained’ have been widely used to describe personality traits. While right-brained people are said to be more artistic or creative, left-brained individuals are supposedly better at thinking analytically.

This division or lateralization of the brain has been found to be true for certain functions. Regions on the right side have been linked to spatial abilities, face recognition and processing music – skills that could be seen as artistic in nature. However, activity on the right side of the brain has also been seen when performing rough mathematical estimations and comparisons. Activity on the left side of the brain has been linked to processing language, performing logical reasoning and precise mathematical computations.