Article

Modeling rhythmic interlimb coordination: The roles of movement amplitude and time delays

Institute for Fundamental and Clinical Human Movement Sciences, Faculty of Human Movement Sciences, Vrije Universiteit, Van der Boechorststraat 9, 1081 BT Amsterdam, The Netherlands; Center for the Ecological Study of Perception and Action, University of Connecticut, Storrs, CT 06269, USA
Human Movement Science 01/1999; DOI: 10.1016/S0167-9457(99)00011-1

ABSTRACT Rhythmic interlimb coordination is characterized by attraction to stable phase and frequency relations. Sudden transitions between the resulting coordination patterns, which are observed when movement frequency is gradually increased, have been modeled at two formally related levels: a potential function and a system of coupled oscillators. At the latter level of the model, two alternative derivations resulted in different predictions with respect to the way in which movement frequency and amplitude affect pattern stability. Our recent results contradicted the prevailing version of the model, which predicts that the influence of movement frequency is fully mediated by the associated changes in amplitude. Although the results could be reconciled with the alternative derivation of the model in which time delays (possibly related to neurophysiological delays) were incorporated, the absence of amplitude-mediated effects on pattern stability challenges both versions of the model. It is argued that by studying coordination dynamics at the level of the potential function as well as at the level of coupled oscillators, new insights into the way in which control parameters influence pattern dynamics may be obtained. This may open up ways to link the coordination dynamics to specific characteristics of the movements of the limbs and the way in which they interact.PsycINFO classification: 2300; 2330

0 Bookmarks
 · 
30 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Coordinated bimanual movements form the basis for many everyday motor skills. In human bimanual coordination there are several basic principles or default coordination modes, such as the preference for in-phase or anti-phase movements. The objective of our work is to make robots learn bimanual coordination in a way that they can produce variations of the learned movements without further training. In this paper we study an artificial system that learns bimanual coordination patterns with various phase differences, frequency ratios and amplitudes. The results allow us to speculate that when the relationship between the two arms is easy to represent, the system is able to preserve this relationship when the speed of the movement changes.
    Artificial Neural Networks - ICANN 2010 - 20th International Conference, Thessaloniki, Greece, September 15-18, 2010, Proceedings, Part III; 01/2010
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Attentional asymmetry in rhythmic interlimb coordination induces an asymmetry in relative phase dynamics, allegedly reflecting an asymmetry in coupling strength. However, relative phase asymmetries may also be engendered by an attention-induced difference between the amplitudes (and hence the preferred frequencies) of the limb movements. The authors conducted 3 experiments to dissociate those (not mutually exclusive) potential effects. Controlled manipulations of amplitude disparity and attentional focus, both alone and combined, revealed that variations in amplitude disparity had the expected effects, but produced evidence against the currently prevailing interpretation that attentional asymmetry affects the relative phase dynamics through an asymmetry in coupling strength. Implications of these findings are discussed vis-à-vis recent empirical findings and extant dynamical models.
    Journal of Experimental Psychology Human Perception & Performance 07/2009; 35(3):762-77. · 2.40 Impact Factor
  • European Journal of Cancer - EUR J CANCER. 01/2011; 47.

Full-text (2 Sources)

View
53 Downloads
Available from
May 21, 2014