"A comparison of brain-imaging scans of non-jugglers and other volunteers before they learned to juggle and three months later, revealed an increase in gray matter in certain areas of the newly trained jugglers' brains."

"Gray matter refers to parts of the brain and spinal cord that are comprised of the tightly packed nuclei of nerve cells. In the brain it is mainly found in the outer layers of the cerebrum which is responsible for advanced mental functions. "

Hear that? Juggling gives you *advanced mental functions*.Link