Pj. Beek et al., LIMIT-CYCLE PROPERTIES OF RHYTHMIC FOREARM MOVEMENTS, Journal of experimental psychology. Human perception and performance, 22(5), 1996, pp. 1077-1093
The kinematics of 1- and 2-armed rhythmic forearm movements were exami
ned using the methodology and limit cycle modeling strategy of B. A. K
ay, J. A. S. Kelso, E. L. Saltzman, and G. Schoner (1987). As frequenc
y was paced from 1 to 6 Hz (in steps of 1 Hz), amplitude decreased in
all 7 participants, whereas peak velocity showed different trends for
different participants. The data of 2 of the 7 participants could be d
escribed with Kay et al.'s model. To account for the data of the remai
ning 5 participants, a new model was proposed with a dissipative struc
ture involving a frequency-dependent Rayleigh term and a standard Van
der Pol term. For 2 of these 5 participants, the coefficient of the Va
n der Pol term was not significantly different from zero. Contrary to
Kay et al.'s model, the new model suggests that the energy bookkeeping
of rhythmic forearm oscillations is affected by the frequency of move
ment.