DAC Distributed Adaptive Control : Theory and Practice

Distributed Adaptive Control (DAC) is a theory of the design principles underlying the Mind, Brain, Body Nexus (MBBN) that has been developed over the last 20 years. DAC assumes that the brain maintains stability between an embodied agent, its internal state and its environment through action. It postulates that in order to act, or know how, the brain has to answer 5 fundamental questions: who, why, what, where, when. Thus the function of the brain is to continuously solve the socalled H5W problem with ‘H’ standing for the ‘How’ an agent acts in the world. The DAC theory is expressed as a neural-based architecture implemented in robots and organised in two complementary structures: layers and columns. The organisational layers are called: reactive, adaptive and contextual, and its columnar organisation defines the processing of states of the world, the self and the generation of action. Each layer is described with respect to its key hypotheses, implementation and specific benchmarks. After an overview of the key elements of DAC, the mapping of its key assumptions towards the invertebrate and mammalian brain is described. In particular, this review focuses on the systems involved in realising the core principles underlying the reactive layer: the allostatic control of fundamental behaviour systems in the vertebrate brain and the emergent non-linearity through neuronal mass action in the locust brain. The adaptive layer is analysed in terms of the classical conditioning paradigm and its neuronal substrate the amygdalacerebellum-neocortex complex together with episodic memory and the formation of sense-act couplets in the hippocampus. For the contextual layer, the ability of circuits in the prefrontal cortex to acquire and express contextual plans for action is described. The general overview of DAC’s explanation of MBBN is combined with examples of application scenarios in which DAC has been validated, including mobile and humanoid robots, neurorehabilitation and the large-scale interactive space Ada. After 20 years of research DAC can be considered a mature theory of MBBN. 1 | Preface