Scientists have discovered that when jazz musicians improvise, areas of their brains associated with inhibition quiet down, and those involved with self-expression heat up. The study required a little technical ingenuity, since the scientists needed to use fMRI to read what was going on in the musicians brains, and the powerful magnets in those scanners mean you cant use standard instruments with metal parts. Charles Limb, a jazz saxophonist who doubles as a scientist at Johns Hopkins University, and his group recruited six jazz pianists, and had them jam on the special keyboard while watching the fMRI machine read their brain activity.