title: Multiplicative-cascade dynamics in pole balancing.
abstract: Pole balancing is a key task for probing the prospective control that organisms must engage in for purposeful action. The temporal structure of pole-balancing behaviors will reflect the on-line operation of control mechanisms needed to maintain an upright posture. In this study, signatures of multifractality are sought and found in time series of the vertical angle of a pole balanced on the fingertip. Comparisons to surrogate time series reveal multiplicative-cascade dynamics and interactivity across scales. In addition, simulations of a pole-balancing model generating on-off intermittency [J. L. Cabrera and J. G. Milton, Phys. Rev. Lett. 89, 158702 (2002)] were analyzed. Evidence of multifractality is also evident in simulations, though comparing simulated and participant series reveals a significantly greater contribution of cross-scale interactivity for the latter. These findings suggest that multiplicative-cascade dynamics are an extension of on-off intermittency and play a role in prospective coordination.
authors.affiliation: Center for the Ecological Study of Perception and Action, Department of Psychology, University of Connecticut, 406 Babbidge Road, Unit 1020, Storrs, Connecticut 06269-1020, USA.
authors.forename: Henry S
authors.initials: HS
authors.lastname: Harrison
authors.affiliation: Center for the Ecological Study of Perception and Action, Department of Psychology, University of Connecticut, 406 Babbidge Road, Unit 1020, Storrs, Connecticut 06269-1020, USA and Department of Psychology, Grinnell College, 1116 8th Avenue, Grinnell, Iowa 50112, USA.
authors.forename: Damian G
authors.initials: DG
authors.lastname: Kelty-Stephen
authors.affiliation: Department of Physical Therapy, Universidade Federal de Minas Gerais, Avenida Presidente Antônio Carlos, 6627, Belo Horizonte, MG, 31270-901, Brazil.
authors.forename: Daniela V
authors.initials: DV
authors.lastname: Vaz
authors.affiliation: Center for the Ecological Study of Perception and Action, Department of Psychology, University of Connecticut, 406 Babbidge Road, Unit 1020, Storrs, Connecticut 06269-1020, USA.
authors.forename: Claire F
authors.initials: CF
authors.lastname: Michaels
mesh_terms: D000465:Algorithms; D059031:Anticipation, Psychological; D003198:Computer Simulation; D005385:Fingers; D017709:Fractals; D006801:Humans; D008962:Models, Theoretical; D009048:Motor Skills