Brain and Behavior: Hierarchy of Feedback Systems and Control of Input

Abstract

The cornerstone of this chapter is W. Powers' definition of behavior: behavior is the control of the sensory input of the organism. By definition, behavior is conceived as a process by which the organization inside the organism controls the input of the organism; the brain is thereby conceived as an integrated whole of negative feedback systems controlling this input. In this chapter I have attempted to elaborate the usefulness of this concept for getting insight into basic functions of distinct neuronal substrates in programming behavior. For that purpose the relational and dynamic features of different levels of cerebral organization of behavior (hierarchies) are examined. I discuss how input signals derived from interoceptive, proprioceptive, and exteroceptive stimuli are transformed into abstract, invariant functions, the degree of abstraction of these stimuli increasing at each higher order level within the hierarchy. I also discuss how behavioral commands result from behavioral program signals, the degree of freedom in programming behavior decreasing at each lower order level in the hierarchy. The usefulness of Powers' concept is illustrated by investigating how information that is sent to the neostriatum is transformed on its way downstream in the hierarchy.