You’ve got to feel a little bit sorry for the cerebellum. When most people think of the brain and its various functions, chances are it’s the cerebrum they think of. With its two hemispheres and layer of gray matter known as the cerebral cortex, this is the part of the organ responsible for "higher functioning" like language and cognition. And it usually gets all the credit for doing our thinking.
But a fascinating paper published last month in the journal Neuron suggests that the cerebellum may play a more important role in shaping those higher functions than previously thought. It might be that dysfunction within the cerebellum at crucial moments in development may contribute to autism spectrum disorders (ASDs) and other neurodevelopmental disorders later in life.
Like the cerebrum, the cerebellum has two hemispheres, separated by a structure called the vermis. Though it makes up only about 10 percent of the brain’s mass, 50 percent of the brain’s neurons are found there. Its main role is commonly thought to be coordinating our movements. When I’m doing a neurological exam on a patient, I’ll check for damage to the cerebellum by testing patient's balance and their ability to perform rapid alternating motions.
However, according to Dr. Samuel Wang and his co-authors, the cerebellum may play a much larger role in shaping our brains’ functions beyond our motor abilities. In a detailed review of existing research, Dr. Wang, an associate professor of molecular biology and neuroscience at Princeton University, puts forth the theory that the cerebellum is responsible for helping developing minds process complex sensory information necessary to form normal social relationships. In cases where something goes awry in this process, other structures in the brain are affected, and ASDs may result.