The findings of researchers at Washington University School of Medicine in St. Louis propose that the cerebellum has an influence in every aspect of higher brain functions, not just movement.
In the better-known cerebral cortex, the wrinkly outer layer of the brain, connecting maps have been drawn, which connect distant areas into networks that govern vision, attention, language and movement. But nobody knew how the cerebellum is ordered in people, partially as a twist of MRI technology. This means that data acquired from the underside of the brain tend to be low quality.
As it turns out, only 20 percent of the cerebellum is devoted to movement, about the same amount as in the cerebral cortex. The remaining 80 percent is engaged by networks involved in higher-order cognition, namely the attention network which is a default network and has to do with daydreaming, recalling memories and just idly thinking. It also contains two networks that supervise supervisory functions such as decision-making and planning.
Individuals with damage to their cerebellum are recognized to become uncoordinated, with an unstable pace, garbled speech and struggle with fine motor tasks. The cerebellum also is fairly sensitive to alcohol, which is one of the reasons why people who have had too many drinks trip around. But the new data may help explain why someone who is intoxicated also displays poor judgment.