Dynamics of 1 : 2 coordination: Sources of symmetry breaking
Journal/Book: J Motor Behav. 1999; 31: 1319 Eighteenth St NW, Washington, DC 20036-1802, USA. Heldref Publications. 224-235.
Abstract: Three asymmetries in the dynamics of 1:2 interlimb coordination were examined: the asymmetry in uncoupled frequencies, the asymmetry in coupled frequencies, and the left-right functional asymmetry of the body. In a bimanual 1:2 task, participants (N = 8) oscillated hand-held pendulums whose uncoupled frequencies were adjusted so that the first kind of asymmetry could be manipulated. For any given pendulum pair, the pendulum assuming the faster motion in the 1:2 coordination was oscillated in the right and the left hands. By assigning combinations of uncoupled eigenfrequencies and coupled task-specified frequencies across hands, the authors studied the interaction of all 3 asymmetries. The results confirm the appropriateness of generalized relative phase as a collective variable for 1:2 coordination. Additionally, they suggest that the generalized form of the detuning parameter represents the first asymmetry and that the coupling function expresses the second asymmetry. In 1:2 coordination, the body's functional asymmetry plays a limited role.
Note: Article Sternad D, Penn State Univ, Dept Kinesiol, 266 Recreat Bldg, University Pk,PA 16802 USA
Keyword(s): bimanual coordination; bimanual symmetry; coupled oscillator dynamics; MOVING VISUAL ENVIRONMENT; ACTION-PERCEPTION CYCLE; HUMAN HAND MOVEMENTS; BIMANUAL COORDINATION; MULTIFREQUENCY COORDINATION; RHYTHMIC COORDINATION; PHASE-TRANSITIONS; POSTURAL CONTROL; ASYMMETRIES; HANDEDNESS