Synergetics of brain function.

The brain is a self-organizing system that operates near points of instability, where collective variables called order parameters govern the activity of individual neurons. This principle is demonstrated through experimental and theoretical studies of finger movement coordination and MEG measurements. The paper focuses on visual pattern recognition, showing that bistability, hysteresis, and oscillations in visual perception can be modeled using order parameters. At the microscopic level, a network of pulse-coupled neurons accounts for both pulse synchronization and pattern recognition. The concept of quasi-attractors is introduced to describe how the visual system shifts between states depending on incoming signals. The paper also interprets consciousness in terms of order parameters and discusses nonlinearity, the binding problem, and the psychological present.

Study at a glance

Abstract

Several brain functions such as movement coordination and visual perception are analysed in terms of synergetics, an interdisciplinary field of research dealing with spontaneous pattern formation. Accordingly, the brain is conceived as a self-organizing system operating close to instabilities where its activities are governed by collective variables, the order parameters, that enslave the individual parts, i.e., the neurons. In this approach, emphasis is laid on qualitative changes of behavioral and neuronal activities. These concepts are substantiated by detailed experimental and theoretical studies of the coordination of finger movements by direct observation of their changes and MEG measurements. In its main part, this paper deals with visual pattern recognition. Using general properties of order parameters, at the phenomenological level bistability, hysteresis and oscillations of visual perception can be modelled. Then, at the microscopic level, a network of pulse-coupled neurons is treated, where the dynamics of the dendritic currents as well as the axonic pulses (spikes) are taken into account. Both pulse-synchronization as well as pattern recognition are treated. In the high pulse frequency limit the attractor network of the synergetic computer is recovered. In the next step, the concept of quasi-attractors is mathematically formulated where due to saturation of attention attractors are closed. Depending on incoming signals, the visual system thus wanders from quasi-attractor to quasi-attractor. The paper includes an interpretation of consciousness in terms of order parameters as well as a discussion on linearity versus nonlinearity, the binding problem, and the psychological "present".