Development of Infant Action Systems and Exploratory Activity: A Tribute to Edward S. Reed

I use Edward S. Reed's work on action systems as a framework to discuss an ecological approach to the development of infant action. I use illustrations from infant action to argue that during development, infants make use of the intrinsic dynamics of their spontaneous motor activity, under a variety of task constraints, to create a small set of action systems. The paper focuses on dynamical systems that generate oscillations as the basis for observable rhythmic behaviors during infancy, such as rocking, shaking the arms, and babbling. Data are presented to illustrate the development of action systems for crawling, object manipulation, and speech. Particular underlying dynamical systems, under different task constraints, may transform body effectors into task-specific action systems: The leg becomes a "kicker," the arm holding a rattle becomes a "shaker," and the vocal tract a "talker."