This story is a supplement to the feature "So You Think You Can Dance?: PET Scans Reveal Your Brain's Inner Choreography" which was printed in the July 2008 issue of Scientific American.

To identify the brain areas that control dance, researchers first need a sense of how the brain allows us to carry out voluntary movements in general. A highly simplified version is presented here.

Motion planning (left) occurs in the frontal lobe, where the premotor cortex on the outer surface (not visible) and the supplementary motor area evaluate signals (arrows) from elsewhere in the brain, indicating such information as position in space and memories of past actions. These two areas then communicate with the primary motor cortex, which determines which muscles need to contract and by how much and sends instructions down through the spinal cord to the muscles.

Fine-tuning (right) occurs, in part, as the muscles return signals to the brain. The cerebellum uses the feedback from the muscles to help maintain balance and refine movements. In addition, the basal ganglia collect sensory information from cortical regions and convey it through the thalamus to motor areas of the cortex.