Informational and mechanical coupling dynamics in bat-ball coordination

Date of Completion

January 1994


Psychology, Experimental




The interdisciplinary field of synergetics provides an explanation of the behavior of complex systems through an analysis of the dynamics of their collective variables, or order parameters (Haken, 1983). Following synergetic principles, Schoner and Kelso (1988a; 1988b) offer an analysis of how a pair of coupled oscillatory systems might adjust their intrinsic dynamics to produce the order parameter dynamics required for an intended dynamical behavioral pattern. This dynamics may depend on extrinsic influences from environmentally specific information (e.g., targets to be reached). Here target information is treated as an additional forcing function on the coupled system whose influence causes the system's order parameter dynamics to move from its old equilibrium state to a new equilibrium state indicative of the intended behavior pattern. In the present experiments this dynamical theory of behavioral patterns is applied to the coordination patterns observed in the performance of the simplest bat-ball skill--repetitively striking a ball on a string with a pendular bat. The bat-ball coordination problem requires coordination between a biological system and a mechanical system; it is a problem of forced coordination between a forcing biological system and a forced mechanical system. Experiment 1 investigated the problem of intrinsic order parameter dynamics, that is, the dynamics in the absence of any behaviorally specific environmental constraints. Experiment 2 examined the problem of required dynamics in batting the ball in a stable cyclic fashion to a hard surface. Predictions from the equations were supported by data from both experiments. Experiment 3 examined the problem of batting the ball to a nonresistant (visually specified) target at a specified distance. The results obtained accorded with the basic assumption of environmental information as an additional forcing term directly influencing the order parameter dynamics. In sum, bat-ball skill investigated in this research may provide an experimental vehicle for further understanding the order parameter dynamics of behavioral patterns, and thereby advance the formal analysis of the perception-action achievements of humans and other animals. ^