Perceptual control theory (PCT) is a psychological theory of animal and human behavior. PCT postulates that an organism's behavior is a means of controlling its perceptions. The model is based on the principles of negative feedback [1]. It is to some extent an application of the ideas used in the engineering discipline of control theory to the modeling of the human mind and behavior.
PCT postulates that layers of control systems, which have access to a metric to optimize and some set of policies or actions, can maintain balancing-acts for difficult, high-abstraction things without developing any explicit model for how those actions relate to the metric being tracked. The brain is postulated to be one of these multi-layered PCTs.
Physical movements are a favorite case-study, since they're relatively easy to break down into this these sorts of layered control theory sub-problems. An important subtlety is that the control systems are optimizing for the perception of a state, rather than for a concrete environmental state itself....