The Significance of Nonlinear Phenomena for the Investigation of Cognitive Systems

Abstract

There are good reasons for understanding the brain as a complex self-organizing system. Despite the fact that nonlinear phenomena are an indicator for self-organization they are only rarely reported in psychological research. Some possible explanations for that are discussed: The preference of homeostatic models, the lack of dynamic measurement and the tendency to reduce complex cognitive phenomena to elementary processes. The synergetic approach presents a model of brain-mind interaction. Synergetics postulate pattern recognition as an analogue to pattern formation. In that view cognitive processes are directly represented by the macrodynamics of the brain. In the article first nonlinearities in complex learning tasks (learning plateaus) are presented and interpreted as the emergence of a hierarchy of self-organizing order parameters. The second example of important nonlinearities in cognitive systems are multistable perceptions. Here we find that minimal semantic influences may affect the perceptual dynamics during the instable phase. A further field of nonlinearities in perception is represented by the hidden potential landscapes of homogeneous areas. Using the method of serial reproduction an attractor structure is revealed which is again sensitive to semantic influences. Finally it is demonstrated that even complex human actions may be analyzed as an attractor driven self-organizing process explaining sudden behavioral changes.