One of the central tenets of direct perception is that action and perception have evolved in parallel and deserve consideration as a unitary system (e.g., Gibson, 1979). By applying the tools of nonlinear dynamics, the relation between perception and action can be characterized in terms of a suitable collective variable, such that perception-action may be understood as a pattern formation process. Taking this approach, perception-action patterns can thus be mapped onto attractors of the respective collective variable dynamics. In the task of synchronization between a limb and a regularly occurring event in the environment, macroscopic patterns formed by the perception-action system correspond to empirically observed stable and unstable phasing relations between elements (Schoner & Kelso, 1988). This relation is captured in the collective variable relative phase which encapsulates all stable coordinative states. The component dynamics, in the form of limit-cycles, elucidate features which are not adequately characterized at the level of the collective variable (Byblow, Carson, & Goodman, submitted).