The Input-Output Organization of the Cerebrocerebellum as Kalman Filter

This chapter brings enigmatic connectivity of the cerebellar dentate nucleus (DN) and the cerebellar forward model hypothesis together to demonstrate the cerebrocerebellum as loci of Kalman filters. We start with a brief history of the cerebellar internal model hypothesis. Next we present two lines of new evidence for the forward model hypothesis. First, we show physiological evidence that the cerebellar outputs from DN are predictive for the inputs to the cerebrocerebellum. Second, we introduce an enigmatic MF collateral to DN and demonstrate it is an essential key to the Kalman filter model. We further discuss how the Kalman filter model for the motor cerebrocerebellum could be generalized to non-motor parts as a unifying principle for the diverse functions of the cerebrocerebellum. We conclude that the Kalman filter model also explains how parallel modules in the cerebrocerebellar communication loops are coordinated in a cascadic manner, providing a partial explanation for unity of mind.