Previous studies conducted by the University Medical Centre Hamburg-Eppendorf in Germany, found that juggling increases the brain's grey matter, where nerve cell bodies are contained. Grey matter gets all the attention in learning studies. It has proven connections to memory, language, focus—all the important details involved in thinking. But this project looked instead at the brain's white matter, where densely packed nerve fibers conduct impulses from the cell bodies.
After six weeks the brains of the non-jugglers showed no change. The jugglers, however, grew white matter in areas of the brain related to vision and movement. Interestingly, it didn't matter how well they could perform.
Four weeks after the juggling training program ceased, University of Oxford researchers again scanned the jugglers' brains. They found that newly developed white matter remained and the grey matter increased. These results indicate that the brain's structure retains benefits from the process of active learning. The results also provide landmark proof that white matter is a significant player in neurodevelopment.
These findings are echoed by the research and case studies discussed in neurologist Frank R. Wilson's book, The Hand: How Its Use Shapes the Brain, Language, and Human Culture. Wilson contends that hands-on experiences boost learning, shape intelligence and determine the future for each individual. According to Dr. Wilson, it doesn't matter if we learn juggling, flower arranging or motorcycle repair. He says, “The desire to learn is reshaped continuously as brain and hand vitalize one another…” What matters is that we learn directly.