Stability and Instability in Autonomous Systems

Behaving systems, biological as well as artificial, need to respond quickly and accurately to changes in the environment. The response is dependent on stored memories, and novel situations should be learnt for the guidance of future behavior. A highly nonlinear system dynamics is required in order to cope with a complex and changing environment, and this dynamics should be regulated to match the demands of the current situation, and to predict future behavior. If any of these regulatory systems fail, the balance beween order and disorder can be shifted, resulting in an inappropriate and unpredictable behaviour. I discuss how such "mental disorders" might be related to the structure and dynamics of any autonomous cognitive system.