A New Theory of Cerebellar Function

Abstract

A new theory of cerebellar function is proposed. It is suggested that the cerebellum works according to a hitherto unknown principle of motor control. A simple learning process in the cerebellum, the 'coupling operation', seems powerful enough to explain the role of this brain part in training and performance ofcomplex motor skills. The coupling operation greatly enhances the capability to perform fast, accurate and highly coordinated motions. These motions can be executed by many different paths, while being well adapted to changing intentions and situations. However, the cerebellar 'coupling machine' does not control movements by itself ; rather, it is a supportive device. In the case of skilled motions, for instance, the control is always left to the forebrain. A network model of the cerebellum demonstrates how the coupling operation might be carried out in cellular detail in a biologically plausible way. According to the theory, the cerebellum only influences complex voluntary movements, and not simple ones. This theory explains a great deal of physiological, anatomical and clinical data, producing a coherent picture.