A Model of Mind-Formation

Abstract

A model of formation of mind is proposed giving an example of small size neuron networks. Neural system changes its structure along with the growth of a creature. However, there are two ways of thinking that neuron networks are decided a priori by the heredity or a posteriori by the interaction with the outer world. First it is discussed that the rough structure of neuron networks may be given a priori but the fine structure, such as synaptic conductance, must be decided a posteriori. Secondly the final goal of neuron networks is discussed, and it is supposed that a neural system changes its structure aiming appropriate input stimuli; that is, it does not want too strong stimuli nor too weak stimuli. This supposition is confirmed by the study of the reflex arc for avoidance of dangers, along with the discussions of the homeostasis of creatures and the teaching principles. The result is represented by a performance index of the total neural system. Finally it is discussed how the synaptic conductances in the neural system are determined to appropriate values. It is shown that synapses would find appropriate conductances by jittering their conductances and checking the response of the performance index. The proposed model is deduced by the discussion of small size networks, however we hope that a similar model can be adapted to bigger networks, too.