Handedness and the asymmetric dynamics of bimanual rhythmic coordination.

Human handedness was investigated in a 1:1 interlimb rhythmic coordination in which consistent and inconsistent left-handed and right-handed individuals oscillated hand-held pendulums. Mean phase difference (φstable) and its standard deviation (SDφ) were evaluated as functions of mode of coordination (in-phase vs anti-phase) and the symmetry conditions imposed by controlling the natural frequencies of the left and right pendulums. The dependencies of φstable and SDφ on coordination mode and imposed symmetry were found to be systematically affected by handedness. The data were consistent with an elaboration of the established order parameter dynamics of interlimb rhythmic coordination. The elaboration includes additional 27π periodic terms that break the symmetry of those dynamics when the natural frequencies of the component rhythmic units are identical. (PsycINFO Database Record (c) 2010 APA, all rights reserved)