Parents have a new reason to plant their kids on a piano bench after school. A new study conducted by researchers at Harvard Medical School indicates that children who diligently practice music can strengthen connections between the two hemispheres of their brains. According to a report in Science:

In 1995, a study led by neurologist and neuroscientist Gottfried Schlaug found that professional musicians who started playing before the age of 7 have an unusually thick corpus callosum, the bundle of axons that serves as an information superhighway between the left and right sides of the brain.

At the time, skeptics argued that the musicians Schlaug studied may have possessed large corpora collosa to begin with. They claimed that it was because of the musicians’ strong neural connections that they pursued music in the first place.

Now, after further investigation, Dr. Schlaug and his team have gathered evidence that strongly supports the findings of the initial study:

The researchers collected detailed magnetic resonance images of the children’s brains at age 6 and again at 9. Of the original group, six children faithfully practiced at least 2.5 hours a week in the time between the scans. In these budding musicians, a region of the corpus callosum that connects movement-planning regions on the two sides of the brain grew about 25% relative to the overall size of the brain. Children who averaged only an hour or two of weekly practice and those who dropped their instruments entirely showed no such growth.

But what can happen to a child whose corpus callosum is partly or completely missing? A recent episode of CURIOUS called “Mind Brain Machine” follows the story of Tony Grobmeier, who is missing his corpus callosum–a condition called agenesis of the corpus callosum. You can watch a video about Tony and read about his physician, Dr. Lynn Paul, who is trying to find out how Tony’s brain functions.

Watch the full episode of Curious: Mind Brain Machine online.

To see a visual representation of brain anatomy, take a 3-D tour of the brain at Secret Life of The Brain.