Purkinje cells of the cerebellum fine-tune coordinated motor movements.
A team of researchers at Johns Hopkins University has unearthed exciting new details about how cerebellar Purkinje cells (link is external) master complex movements through a trial-and-error learning process in which each error that occurs during practice helps the cerebellum improve fine-tuned motor coordination. This paper, “Encoding of Error and Learning to Correct That Error by the Purkinje Cells of the Cerebellum (link is external),” was published online April 16 in the journal Nature Neuroscience.
The most significant aspect of this study is that senior author Reza Shadmehr (link is external), professor of biomedical engineering and neuroscience at the Johns Hopkins University School of Medicine, and colleagues have pinpointed how Purkinje cells work. This research adds fresh insight and empirical evidence to support landmark papers from the 20th century that speculated about what the mysterious Purkinje cells were actually doing such as “The Cerebellum as a Neuronal Machine (link is external),” (John Eccles, et al. 1967), “A Theory of Cerebellar Cortex (link is external)” (David Marr, 1969), and “A Theory of Cerebellar Function (link is external)
A May 3, 2018 press release about the cutting-edge Purkinje cell research being conducted at Johns Hopkins Medicine, “Decoding the Brain’s Learning Machine (link is external),” describes the cerebellum as a “learning machine” within the mammalian brain. Their most recent study on monkeys shows that Purkinje cells make predictions and learn how to master complex tasks by constantly correcting little mistakes. With practice, errors decrease and precision increases. Over time, this results in what I call “superfluidity (link is external).”
As an athletic example of Purkinje-based cerebellar mastery, the statement says: “When learning to shoot a basketball, people usually miss many times before getting one shot through the hoop. As the arm moves, the cerebellum makes predictions about the consequences of the action. When the prediction does not match reality — that is, the ball misses the hoop — the cerebellum receives feedback from the eyes and the arm to learn from the error, fine-tuning factors such as aim, force and release to make a basket. This trial-to-trial learning from error produces gradual improvements in performance” The same process of trial-and-error cerebellar learning occurs in every sport and helps to explains why practice makes perfect. Notably, having an “eye for the ball” is also directly linked to the cerebellum and our vestibulo-ocular reflex (link is external) (VOR).