Abstract des Autors

The in-phase and antiphase patterns of interlimb 1:1 frequency locking were contrasted with respect to models of coordination dynamics in biological movement systems that are based on diffusive coupling, synptic coupling, and synergetic principles. Predictions were made from each model concerning the stable relative phase phi between the rhythmic units, its standard deviation SD-phi and the self-chosen coupled frequency omega-c The experimental task involved human subjects oscillating two handheld pendulums either in-phase or antiphase. The eigenfrequencies of the two hand-pendulum systems were manipulated by varying the length and mass of each pendulum individually. Relative to an eigenfrequency difference of delta-omega equal to zero, delta > 0 displaced phi from phi = 0 and phi = pi, and amplified SD-phi. Omega-c decreased with delta-omega. Both the displacement of phi and SD-phi were greater in the antiphase mode. Additionally, the displacement of phi increased more sharply with delta-omega for antiphase than for in-phase coordination. In contrast, omega-c was identical for the two coordination modes. Of the models of interlimb coordination dynamics, the synergetic model was the most successful in addressing the pattern of dependencies of phi and SD-phi. The specific forms of the functions relating omega-c and phi to delta-omega pose challenges for all three models, however. Verf.-Referat