Chapter 10 Asymmetries in the dynamics of interlimb coordination

Two experiments were conducted to examine whether asymmetries in cortical organization with respect to timing functions are expressed in the dynamics of self paced, and externally paced, rhythmic coordination tasks. Four subjects performed movements of the ankle and the wrist, in two modes of coordination, anti-phase and in-phase. In Experiment 1, subjects conducted these movements at their preferred frequencies. In Experiment 2 their movements were paced by an auditory metronome at 1 Hz and 2 Hz. Coordination dynamics were examined at both the kinematic (Experiments 1 & 2) and the neuromuscular (Experiment 1) levels of observation. When self-paced, movements of the left side were more variable with respect to oscillation frequency than movements of the right side. Uniformity of the order parameter, relative phase, was also greater for movements of the right side. These differences were eliminated when movements were externally paced.