Dynamical models of movement coordination

Abstract

This article examines the status of dynamical models of movement coordination qua phenomenological models. After a brief outline of the aims, methods and strategic assump tions of the dynamical systems approach, a survey is provided of the theoretical and empirical progress it has made in identifying general principles of coordination. Although dynamical models are constructed for phenomena at a particular level of analysis for which they provide descriptive explanations, their dynamics can sometimes he linked to or associated with the dynamics of processes at other levels of analysis. The article concludcs with a tentative scheme to clarify the position of the dynamical approach relative to other ex! an I approaches in movement science, « W ipBodily movements occur in the context of the everyday functioning of people while realizing specific task goals. As a rule, such movements involve the participation of multiple joints and limbs. When in action, these body parts are coordinated, that is, they are brought into proper relation to one another as well as to the surrounding layout of surfaces (cf. Turvey, 1990). To the naked eye, this coordination may look relatively simple, as in picking up an object, or relatively complicated, as in juggling, performing an attacking forehand drive in table tennis or playing the drums. To the ( 'orrcspoiKling author. Tel.: +31 20 444 8532. Fax: +31 20 444 5867. E-mail: 1' .1 HeekWl'BW .VU.NL (l|li7-lM 5 7 /l)5/$(W.50 < v> 1W5 I Use vier Science U.V. A ll lights reserved S S D I 0 I ()7-t) 4 5 7 ( t>5 MI0028-3 movement scientist, however, all coordination is complex in that he or she is confronted with the challenge to explain coordinated movements as the orderly products of a hybrid biological organization involving a very large number of different subsystems (e.g., vascular, neural, muscular, skeletal). These subsystems are operating at different rates and are connected in intricate ways. Due to this compositional complexity, the problem of movement coordination is extremely difficult to resolve in a scientifically satisfactory way. Finding an adequate solution is hampered by the fact that the field of motor control is still very much partitioned according to the traditional disciplines of movement science (mechanics, neuropliysiology, psychology, and so on), whereas a multidisciplinary or interdisciplinary approach is required.Broadly speaking, two types of approaches may be distinguished in movement science: structural and phenomenological approaches (ef, Otten, 1991). Structural approaches seek causal explanations of movement in terms of dedicated structures within the human body. Phenomenological approaches, in contrast, seek noncausal explanations in terms of phe nomenological laws and principles without reference to dedicated mecha nisms and structures within the human body.Structural models of motor control are typically (neuro)physiological models which attempt to explain different aspects of motor behaviour on the basis of hypothetical (neuro)physiologieal m...

Deterministic and stochastic features of rhythmic human movement

“…A more rigorous way to compute parameter values is to regress all state variables (e.g., position and velocity) onto the analytical form of the W-function. Apart from the aforementioned combination of Rayleigh and van der Pol oscillators, this regression yielded Duffing-like cubic stiffness for swinging a hand-held pendulum at a given frequency and amplitude (Beek et al 1995). In a similar fashion but circumventing collinearity problems in the proposed regression technique, Bootsma et al (1998) and Mottet and Bootsma (1999) studied the dynamics of goal-directed rhythmic aiming movements in the context of a cyclical Fitts' task.…”

Symmetry and order parameter dynamics of the human odometer

“…The second axiom is inspired by various approaches to the self-organization of so-called muscular synergies or coordinative structures-components undergoing orderly time variations in parallel (e.g., Beek et al 1995;Haken 1996;Kelso 1995;Turvey 2007). Axiom 2 is a claim that sequentially coordinated M and R activities emerge from a selforganization process subjected to the given task constraints.…”

On a Nonlinear Master Equation and the Haken-Kelso-Bunz Model

“…In a far-reaching paper, Haken, Kelso, and Bunz proposed a model to describe multistable rhythmic finger movements [5,25,27,28,30]. In literature, this model is referred to as the HKB model.…”

“…It is nowadays well-documented that for low oscillation frequencies humans can perform bimanual oscillatory index finger movements in only two stable stationary patterns: an in-phase pattern (synchronized activity of homologous muscle groups with zero degree phase-difference ⇒ index fingers move anti-parallel) and an anti-phase pattern (synchronized activity of homologous muscle groups with 180 degrees phase-difference ⇒ index fingers move parallel). For high oscillation frequencies there is only one coordination pattern that can be performed in a stable fashion: the in-phase pattern [5,25,27,28,30]. We assign to the in-phase pattern the stationary phase difference φ st = 0 and to the anti-phase pattern the stationary phase difference φ st = π .…”