<Ol> <Li> Metencephalon </Li> <Li> Myelencephalon </Li> </Ol> <Ol> <Li> Pons and cerebellum </Li> <Li> Medulla </Li> </Ol> <Li> Pons and cerebellum </Li> <P> The basal ganglia form a fundamental component of the cerebrum . In contrast to the cortical layer that lines the surface of the forebrain, the basal ganglia are a collection of distinct masses of gray matter lying deep in the brain not far from the junction of the thalamus . They lie to the side of and surround the thalamus . Like most parts of the brain, the basal ganglia consist of left and right sides that are virtual mirror images of each other . </P>

The superior colliculus is located in the (diencephalon / midbrain / basal ganglia / medulla)