Researchers at the Stanford University School of Medicine have shown that parts of the brain network that react to humor in an adult are already present in children ages six to 12. These neural circuits, while present in children, develop into more sophisticated networks as children mature, according to a statement on the School of Medicine’s website.

The research team studied the functional magnetic resonance imaging (fMRI) brain scans of six- to 12-year-old children who watched short video clips. The children in the study were of average intelligence or higher and did not have any psychiatric or developmental problems. The researchers used videos in three categories to evaluate the brain activity: funny, positive and neutral.

According to the School of Medicine’s statement, the funny videos were intended to be rewarding and positive to watch while the positive videos were only intended to be rewarding. The neutral videos were intended to be neither funny nor rewarding.

The researchers found that the funny videos activated two regions in the children’s brains that are also activated in adults’ brains when they view funny material. However, an area of the brain known as the temporal-occipital-parietal junction, which processes perceived incongruities, was activated in both the left and right hemispheres of the children’s brains. This area is only activated on the left side of the brain in adult subjects reacting to similar material. Humor also activated the brain’s mesolimbic regions, which process rewards.

The research team included Allan Reiss, director of the Center for Interdisciplinary Brain Sciences Research at Stanford, and Michelle Neely ’11, currently a Cornell medical student. The study was published in the Feb. 1 issue of the Journal of Neuroscience.

— Alice Phillips