Among the many wonders of the brain is its ability to master learned movements—a dance step, piano sonata, or tying our shoes—acquired through trial-and-error practice. For decades, neuroscientists have known that these tasks require a cluster of brain areas known as the basal ganglia.

According to a new study led by Harvard researchers in Nature Neuroscience, this so-called “learning machine” speaks in two different codes—one for recently-acquired learned movements and another for innate “natural” behaviors. These surprising findings from lab rats may shed light on human movement disorders such as Parkinson’s disease.

“When we compared the codes across these two behavioral domains, we found that they were very different,” said Bence Ölveczky, professor of organismic and evolutionary biology (OEB).