An integrated theory of Mind

There has been a proliferation of proposed mental modules in an attempt to account for different cognitive functions but so far there has been no successful account of their integration. ACT-R (Anderson & Lebiere, 1998) has evolved into a theory that consists of multiple modules but also explains how they are integrated to produce coherent cognition. We discuss the perceptual-motor modules, the goal module, and the declarative memory module as examples of specialized systems in ACT-R. These modules are associated with distinct cortical regions. These modules place chunks in buffers that project to the basal ganglia, which implement ACT-R’s procedural system, a production system that responds to patterns of information in the buffers. At any point in time a single production rule is selected to respond to the current pattern. This serial bottleneck in production-rule selection enables the coordination that results in an organized control of cognition. Subsymbolic processes serve to guide the selection of rules to fire as well as the internal operations of (some) modules and much of learning involves tuning of these subsymbolic processes. We describe empirical examples that demonstrate the predictions of ACT-R’s modules and also examples that show how these modules result in strong predictions when they are brought together in models of complex tasks. These predictions require little parameter estimation and can be made for choice data, latency data, and brain imaging data