Brain-Based Labels Bunk?

An fMRI study shows speculations that people are “left-brained” versus “right-brained” are not backed by evidence.

Aug 19, 2013
Kate Yandell

J.A. NIELSEN ET AL., PLOS ONECreative types have been commonly thought to rely on the right side of their brains, while analytical folk have been considered more “left-brained” thinkers. But people don’t actually show such tendencies toward either left- or right-brained activity, according to a study published last week (August 14) in PLOS ONE.

“It’s 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,” explained study coauthor Jeff Anderson of the University of Utah in a press release. “But people don’t tend to have a stronger left- or right-sided brain network. It seems to be determined more connection by connection.”

Anderson and his colleagues analyzed functional magnetic resonance imaging (fMRI) data from the brains of more than 1,000 resting subjects. While the researchers found that various regions of the subjects’ brains were “lateralized,” with certain mental processes occurring on one side of the brain or the other, across whole brains, neither the left nor the right side seemed to dominate.

“It may be that personality types have nothing to do with one hemisphere being more active, stronger, or more connected,” said coauthor Jared Nielsen, a graduate student in neuroscience at Utah, in the press release.