Cerebellum Models: an Interpretation of Some Features

Abstract

Many authors have studied the functional capacity of cerebellar cortex and its implications on the organismic behaviour. A basic observation is the extremely regular organization of cells in the cortex with their repartition within two layers and the possible functional unity around Purkinje cell. The first theoretical model following Eccles’s experimental works [1] was D. Marr’s one [2]. Indeed Marr used a possible synaptic modification between Purkinje cell and parallel fibres as fundamental hypothesis, but also numerous imaginative suppositions which permit him to conceive a functional and qualitative model. The regular geometry and possible analogies with electronic devices and computation organs induce simple ideas on the functionning of a cerebellar cortex unit. After Marr, J.S. Albus [3] created a quantitative model of cerebellar cortex based on similar properties — but only three — so it was a computer approach rather than a physiological explanation of cerebellar function. That is the reason why he called his model the CMAC or Cerebellum Model Arithmetic Computer. More recent models have been considered by S. Grossberg [4] and J.C.C. Boylls [5].