AdvertisementA WHAT Lives Inside My Brain?March 18, 2009Jenny GoldfacebookEmailThe neurons in your motor cortex are grouped by body part. Parts with a complex range of fine movement, like the hand, take up more space. Parts with a limited range of movement, like the hip, require less space. Together, the various parts form a full, representative map of your body, called a "homunculus." (Posit Science)