# 1A Unified Theory of Action Selection and Memory

The purpose of this chapter is to provide a bird’s-eye view of our project^{1}, the development of a framework for considering the behavior of human beings in the universe, nonlinear dynamic human behavior model with real-time constraints (NDHB-model/RT), and a cognitive architecture, “model human processor with real-time constraints” (MHP/RT), that is capable of simulating human being’s daily decision making and action selection under NDHB-model/RT. The underlying idea is discussed in section 1.1.

**1.1. Organic self-consistent field theory**

**1.1.1. ***Self-consistent field theory in physics*

In physics and probability theory, self-consistent field theory (SCFT), also known as mean field theory, studies the behavior of large and complex stochastic models by studying a simpler model. Such models consider a large number of small interacting individual components, which interact with each other. The effect of all other individuals on any given individual is approximated by a single averaged effect, thus reducing a many-body problem to a one-body problem. In field theory, the Hamiltonian may be expanded in terms of the magnitude of fluctuations around the mean of the field. In this context, SCFT can be viewed as the “zeroth-order” expansion of the Hamiltonian in fluctuations. In reality, this means an SCFT system has no fluctuations, but this coincides with the idea that one is replacing all interactions with a “self-consistent field”. Quite ...