Dynamic emergence and adaptation of behavior through embodiment as coupled chaotic field

A novel model for dynamic emergence and adaptation of embodied behavior is proposed. A musculo-skeletal system is controlled by a number of chaotic elements, each of which driving a muscle based on local sensory feedback. Thus, the chaotic elements interact with each other through the physical body and the environment. This overall structure is modelled as a coupled chaotic system, which has been known in the complex systems science for its capability of creating and moving among extremely rich variety of ordered patterns. In our model, body-environment interaction dynamics, or embodiment, serves as the chaos coupling field, which is nonlinear and time-varying. Theoretically very little is known about such cases, but since the coupling field directly reflects the current body-environment dynamics, we believe that the emergent ordered patterns correspond to useful motor coordination patterns which immediately get reorganized in response to dynamically changing environmental situation. We implemented the above model and carried out a series of experiments using a dynamics simulator. The results confirmed the above conjecture. In a "muscle-joint" model and a "multi-legged insect" model, the systems autonomously explored and found meaningful motor behaviors within a few seconds. And when the environmental condition changes they immediately created novel motor patterns, which comply with the new situation. Unlike existing learning methods, our model does not require long training period or well designed reward function. The emergence and adaptation takes place immediately, and yet effective in the current embodied situation. Furthermore, we present a methodology to introduce "goal-directedness" to the system without destroying its emergent property.