Computer Code Changing values in the symbols and rules of a computer program can lead the results of computer simulation into chaos. Orderly and innate mechanisms are needed to control the evolution of these symbols and rules. Furthermore, changing one set of parameters tend to create conditions which forces changes in other symbolic elements in the code. This leads to an exponential explosion in the complexity of the simulation. The simplest control mechanism to impose on the system is natural selection of state sequences by trial and error.
Symbols representing the state of the system are explicit time-dependent sequences.
These state sequences represent stochastic processes. In the simulation of neural systems, the principles determining the formation of these state sequences are hidden beneath a lower substructure. The knowledge required to predict these sequences resides in the layer between the cellular states and the formation of discrete neural nodes.