However, it is not obvious that CALM is a representation of the neocortical minicolumn based on its generic architecture and nonphysiological parameters. Although any model will fall short in depicting a real system, it is unfortunate that CALM is not developed in a more biologically plausible manner. Two simple suggestions follow. First, refinement of the arousal and learning mechanisms in the model could be consolidated into a neuromodulatory system. The convergence process is unique, but the associated mechanisms of learning, categorizing and separating correlated patterns are rather standard.
More interesting properties arise when several CALMs are linked together.
The book lays some foundations and further work is apparently in progress, but the local and modular features of CALM, as a component of larger networks, have not been fully realized. This is a general comment. In general, the models deal with functional networks, wherein the modules have behavioral but not necessarily structural significance. The behaviors examined by Murre include letter recognition, implicit and explicit memory, and catastrophic sequential interference. In common with other models of layered modules, such as the multi-layered perceptron and neocognitron, small networks of CALM modules produce results that are consistent with known psychological data.