Dynamics of 1 : 2 coordination: Temporal scaling, latent 1 : 1, and bistability

The simplest interlimb multifrequency coordination of 1:2 can be performed at different speeds and in at least two different styles or modes. The effe cts of speed and mode (in-phase or antiphase) were evaluated in a bimanual 1:2 rhythmic task in which participants (N = 8) oscillated hand-held pendul ums with identical or different uncoupled frequencies. A motion equation in relative phase that captures the asymmetries of components and task predic ted the 1:2 coordination equilibria resulting from temporal scaling. Accord ing to the experimental results, both coordination; modes proved to be equa lly stable. More detailed analyses of individual trials showed signs that t he more fundamental 1:1 coordination intruded into the 1:2 coordination.