title: Deterministic and stochastic features of rhythmic human movement.
abstract: The dynamics of rhythmic movement has both deterministic and stochastic features. We advocate a recently established analysis method that allows for an unbiased identification of both types of system components. The deterministic components are revealed in terms of drift coefficients and vector fields, while the stochastic components are assessed in terms of diffusion coefficients and ellipse fields. The general principles of the procedure and its application are explained and illustrated using simulated data from known dynamical systems. Subsequently, we exemplify the method's merits in extracting deterministic and stochastic aspects of various instances of rhythmic movement, including tapping, wrist cycling and forearm oscillations. In particular, it is shown how the extracted numerical forms can be analysed to gain insight into the dependence of dynamical properties on experimental conditions.
authors.affiliation: Institute for Fundamental and Clinical Human Movement Sciences, Vrije Universiteit, Van der Boechorststraat 9, 1081BT, Amsterdam, The Netherlands. a.vanmourik@fbw.vu.nl
authors.forename: Anke M
authors.initials: AM
authors.lastname: van Mourik
authors.forename: Andreas
authors.initials: A
authors.lastname: Daffertshofer
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Beek
mesh_terms: D005542:Forearm / Q000502:physiology; D006801:Humans; D008954:Models, Biological; D009068:Movement / Q000502:physiology*; D017711:Nonlinear Dynamics; D010507:Periodicity; D013269:Stochastic Processes