The cerebellum of our brain that was once believed only limited to movement control has now been associated with playing a key role in higher functions like attention, thinking, planning and decision-making, researchers have found.The cerebellum is like the person at the end of an assembly line, the researchers said, adding "it's where all your thoughts and actions get refined and quality controlled."The findings led by researchers at Washington University in St. Louis showed that the sensory networks -- vision, hearing and touch -- are missing from cerebellum's functions. Only 20 per cent of it is devoted to movement, roughly the same amount as in the cerebral cortex -- the crumpled outer layer of the brain, the remaining 80 per cent is occupied by networks involved in higher-order cognition.These include the attention network; the default network, which has to do with daydreaming, recalling memories and just idly thinking; and two networks that oversee executive functions such as decision-making and planning."The biggest surprise to me was the discovery that 80 per cent of the cerebellum is devoted to the smart stuff," said Nico Dosenbach, Assistant Professor at the University's School of Medicine.
"Everyone thought the cerebellum was about movement. If your cerebellum is damaged, you can't move smoothly -- your hand jerks around when you try to reach for something. "Our research strongly suggests that just as the cerebellum serves as a quality check on movement, it also checks your thoughts as well -- smoothing them out, correcting them, perfecting things," Dosenbach said.For the study, published in the journal Neuron, the team had access to more than 10 hours of scans on each of 10 people and used the cortex's networks as a template to identify the networks in the cerebellum.The researchers measured the timing of brain activity and found that the cerebellum was consistently the last step in neurologic circuits.Signals were received through sensory systems and processed in intermediate networks in the cerebral cortex before being sent to the cerebellum where they underwent final quality checks before the output is sent back to the cerebral cortex for implementation.