10 Percent of Brain
Explanation: No one's sure who thought up the idea that humans use only 10 percent of their brains, but popular culture has adopted it as scientific fact. However, when MythBuster Tory Belleci took a series of mind-bending tests to track how much of his brain got a workout, the results indicated otherwise.
While hooked up to a magnetoencephalogram (MEG), a neuroimaging device that measures magnetic fields produced by the brain's electrical currents, Tory exercised four different neurological regions with memory drills, math calculations, word associations and image comparisons. Over the course of the MEG exam, around 35 percent of Tory's brain jumped into action, busting the brain myth.
Now, the MythBusters just need to figure out how to fire up that remaining 65 percent.