Cerebellum

The Cerebellum is a brain-based neural structure located on the dorsal surface of the pons responsible for muscular coordination of complex movements and also motor learning.

It is involved in complex motions such as catching a baseball: it receives information from proprioceptors that inform the brain the position of the catching limb, approximate the trajectory of the inbound baseball, and coordinate the appropriate muscular contractions and relaxations to intersect the approximated trajectory with the catching limb.