One-to-One and Polyrhythmic Temporal Coordination in Bimanual Circle Tracing

Abstract

The authors manipulated movement amplitude in a bimanual circle-tracing task to alter the natural tracing frequency of the arms. Participants (N = 14) traced different-diameter circles simultaneously with the two arms in either in-phase (0°) or antiphase (180°) coordination, using the index fingers or plastic styli. Movement amplitude altered the natural tracing frequency of the arms, as demonstrated by the following 2 findings: (a) The larger the difference in circle diameter, the larger was the shift from the fixed-point values of 0° and 180°, and the shift increased as movement frequency increased. Those results are consistent with the manipulation of Δω in the bimanual pendulum paradigm, (b) Increasing movement frequency induced transitions from 1:1 to non-1:1 coordination, contrary to findings in previous investigations of polyrhythmic coordination. Tactile feedback played a minimal role in stabilizing bimanual coordination in the current tasks.

Keywords:

• manual asymmetries
• movement amplitude
• sine-circle map
• tactile information feedback
• transitions