Sometimes referred to by its Latin translation as the “little brain”, the cerebellum is located close to the brainstem and sits under the cortex in the hindbrain. New research at San Diego State University, however, calls the “little” terminology into question.
The cerebellum plays a versatile role, contributing to our five senses as well as pain, movements, thought, and emotion.
It’s essentially a flat sheet with the thickness of a crepe, crinkled into hundreds of folds to make it fit into a compact volume about one-eighth the volume of the cerebral cortex. For this reason, the surface area of the cerebellum was thought to be considerably smaller than that of the cerebral cortex.
By using an ultra-high-field 9.4 Tesla MRI machine to scan the brain and custom software to process the resulting images, an SDSU neuroimaging expert discovered the tightly packed folds actually contain a surface area equal to 80% of the cerebral cortex’s surface area. In comparison, the macaque’s cerebellum is about 30% the size of its cortex.
“The fact that it has such a large surface area speaks to the evolution of distinctively human behaviors and cognition,” said Martin Sereno, psychology professor, cognitive neuroscientist and director of the SDSU MRI Imaging Center. “It has expanded so much that the folding patterns are very complex.”