This research will examine patterns of coordinations between the arms as people engage in simple (e.g., two arms moving at one tempo) and complex (e.g., juggling) rhythmic activities. Its objective is twofold, (1) to identify the dynamical principles by which rhythmic coordinations between the limbs can be both stable and adaptive and (2) to understand how these principles affect how the person controls, perceives new aspects of, and learns these coordinations. Some experiments will manipulate the phase relation between limbs, the frequencies at which they move together, and the frequencies at which they move alone. Others will involve skilled juggling under conditions which manipulate variables of the juggled objects and the juggling pattern. The data will be collected using three-dimensional motion analyzers and addressed using the theory and methods of nonlinear dynamics. The results should provide useful constraints on modeling coordination and contribute to the understanding of rhythmic movement disorders.
