According to Fodor (1983), a module is a neural substrate that is specialized for solving a particular information processing problem. An isotropic process is the opposite of a module. It is a general purpose problem solver, and is non-modular because in principle it must have access to all possible information stored in a cognitive system, because at some point in time this information may be required. Isotropic processing, then, characterizes general reasoning. The general properties of modules fast, mandatory processing; fixed neural architecture; belief independence will not be true of isotropic processing. As a result, Fodor has claimed that a cognitive science of isotropic processing will be impossible.
- Fodor, J. A. (1983). The Modularity Of Mind. Cambridge, MA: MIT Press.
(Added October 2010)