The subthalamic nucleus is a small lens-shaped nucleus in the brain where it is, from a functional point of view, part of the basal ganglia system. In terms of anatomy, it is the major part of the subthalamus. As suggested by its name, the subthalamic nucleus is located ventral to the thalamus. The basal ganglia are a group of structures found deep within the cerebral hemispheres. The structures generally included in the basal ganglia are the caudate, putamen, and globus pallidus in the cerebrum, the substantia nigra in the midbrain, and the subthalamic nucleus in the diencephalon. The putamen is a large structure located within the brain. It is involved in a very complex feedback loop that prepares and aids in movement of the limbs. It is closely intertwined with the caudate nucleus, nucleus accumbens, and globus pallidus, which are together known as the corpus striatum. The caudate nucleus plays a vital role in how the brain learns, specifically the storing and processing of memories. It works as a feedback processor, which means it uses information from past experiences to influence future actions and decisions. This is important to the development and use of language.