Study Debunks Pop-Psychology Idea That People Are Either Right- or Left-Brained

Article excerpt

Until early in the 20th century, many people -- including many scientists -- believed that bumps and indentions on the skull helped determine an individual's personality.

That idea -- phrenology -- has been thoroughly discredited, of course. And now it appears it's time to debunk a more recent popular assumption about the brain and personality: the idea that individuals tend to be either more creative or more analytical depending on which side of their brain they use the most.

For a new, large brain-imaging study, published last week in the journal PLOS ONE, has found no evidence that people are predominantly right-brained (creative) or left-brained (analytical).

In other words, differences in cognitive (thinking) style have nothing to do with one hemisphere of the brain being used more often than the other.

A detailed analysis

It was a very thorough study. A team of University of Utah researchers spent two years reviewing the brain scans of 1,011 individuals aged 7 through 29 years. The scans, collected as part of the International Neuroimaging Data-Sharing Initiative, were made while the participants lay in a magnetic resonance imaging (MRI) scanner for five to 10 minutes.

Brain-function lateralization was measured for each participant. (Lateralization refers to the specialization of certain mental processes to primarily one hemisphere of the brain.) The researchers then broke the brain down into 7,000 separate regions and analyzed which regions of each participant's brain showed the most lateralization.

They found brain-connection patterns that were strongly correlated with either the right or the left hemisphere of the brain. Connections associated with language and the perception of internal stimuli (those produced by the body) tended to occur in the left hemisphere, for example, while connections associated with the perception of external stimuli (those produced by the environment outside the body) were more likely to appear in the right hemisphere. …