A Plasma Model of Brain Dynamics

Abstract

A plasma model of the brain is proposed to explain the long range correlations observed in the nervous system of the living brain and to understand such mental functions of the brain as the remembering (as well as forgetting) and the recalling of information received from the external world. In this model a waking but inattentive state of the brain is repre­ sented by a single-humped distribution function for the nerve cell activity (measured by the firing rate of bioelectrical impulses), and an attentive excited state brought about by an ex­ ternal stimulation by a distribution function with a small second hump on the tail. The quasi-linear approximation to the Liouville equation for the activity distribution function in the neural phase space predicts the flattening of the small hump and the formation of a plateau persisting for indefinitely long time, which is interpreted as the . memory process of the brain. The model is compared with the model of Ricciardi and Umezawa, in which the stable memory of the brain is related to the Bose condensation into the ground state of the qnan­ tum many-body system of Goldstone particles which are associated with the spontaneous breakdown of various symmetries in the brain.