Math Comes Naturally

August 1, 2006
Child with an abacus

Four-year-olds show activity in the same brain region during numerical tasks as adults, according to Duke researchers, who used comparative brain-scan studies to explore the earliest glimmerings of numerical processing in preschool children.

The researchers say their findings represent the beginning of a promising approach to exploring how the brain wires itself during development to acquire mathematical skills. They reported in the journal Public Library of Science Biology that a brain region called the intraparietal sulcus (IPS) is activated when both four-year-olds and adults perceive numerical quantities. The researchers used the analytical technique of functional magnetic resonance imaging (fMRI), in which harmless magnetic fields and radio waves provide images of blood flow in brain regions, which reflects their activity.

"Lots of previous behavioral studies have shown that preschool children can do basic math tasks before they ever get any formal math training in school," says Jessica Cantlon, lead author on the paper and a graduate student in the laboratory of co-author Elizabeth Brannon, assistant professor of psychological and brain sciences. "They can tell you that a bag of fifteen grapes has more things in it than a bag of five apples, even if they don't know how to verbally count very well. So, it seems like a basic set of math skills are laid down very early in development. And we were interested in whether these early math skills are related to the sophisticated math skills of adults in the brain."

"This study is the first study to use fMRI to study the neural basis of higher-order cognition in children this young," Cantlon continues. "This is important because very little is known about how the mind of a young child becomes so sophisticated, especially for mathematics, over a relatively short period of time."

The experiment involved showing both children and adults a rapid display of objects, for example, thirty-two circles over and over, says senior author Kevin Pelphrey, assistant professor of psychological and brain sciences. When the subjects became accustomed to seeing thirty-two circles, a display containing sixty-four circles would appear. The fMRI scans would reveal the brain region activated by this change in number.

In behavioral studies, the researchers found that the same children could not verbally count to sixty-four, even though they were capable of discriminating such large numbers when presented in a non-symbolic way.