title: Dynamical signatures of isometric force control as a function of age, expertise, and task constraints.
abstract: From the conceptual and methodological framework of the dynamical systems approach, force control results from complex interactions of various subsystems yielding observable behavioral fluctuations, which comprise both deterministic (predictable) and stochastic (noise-like) dynamical components. Here, we investigated these components contributing to the observed variability in force control in groups of participants differing in age and expertise level. To this aim, young (18-25 yr) as well as late middle-aged (55-65 yr) novices and experts (precision mechanics) performed a force maintenance and a force modulation task. Results showed that whereas the amplitude of force variability did not differ across groups in the maintenance tasks, in the modulation task it was higher for late middle-aged novices than for experts and higher for both these groups than for young participants. Within both tasks and for all groups, stochastic fluctuations were lowest where the deterministic influence was smallest. However, although all groups showed similar dynamics underlying force control in the maintenance task, a group effect was found for deterministic and stochastic fluctuations in the modulation task. The latter findings imply that both components were involved in the observed group differences in the variability of force fluctuations in the modulation task. These findings suggest that between groups the general characteristics of the dynamics do not differ in either task and that force control is more affected by age than by expertise. However, expertise seems to counteract some of the age effects.NEW & NOTEWORTHYStochastic and deterministic dynamical components contribute to force production. Dynamical signatures differ between force maintenance and cyclic force modulation tasks but hardly between age and expertise groups. Differences in both stochastic and deterministic components are associated with group differences in behavioral variability, and observed behavioral variability is more strongly task dependent than person dependent.
authors.affiliation: Institute of Sports Medicine, University of Paderborn, Paderborn, Germany.|Aix-Marseille Université, Centre National de la Recherche Scientifique (CNRS), Institut des Sciences du Mouvement, Marseille, France.|Jacobs Center on Lifelong Learning and Institutional Change, Jacobs University, Bremen, Germany.
authors.forename: Solveig
authors.initials: S
authors.lastname: Vieluf
authors.affiliation: Aix-Marseille Université, Centre National de la Recherche Scientifique (CNRS), Institut des Sciences du Mouvement, Marseille, France.
authors.forename: Rita
authors.initials: R
authors.lastname: Sleimen-Malkoun
authors.affiliation: Jacobs Center on Lifelong Learning and Institutional Change, Jacobs University, Bremen, Germany.|Institute of Human Movement Science and Health, Chemnitz University of Technology, Chemnitz, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Voelcker-Rehage
authors.affiliation: Aix Marseille Université, Inserm, INS, Institut de Neurosciences des Systèmes, Marseille, France.
authors.forename: Viktor
authors.initials: V
authors.lastname: Jirsa
authors.affiliation: Jacobs Center on Lifelong Learning and Institutional Change, Jacobs University, Bremen, Germany.|Centre for Sensorimotor Performance, School of Human Movement and Nutrition Sciences, The University of Queensland, St. Lucia, Brisbane, Queensland, Australia.
authors.forename: Eva-Maria
authors.identifier: 0000-0001-6745-964X
authors.initials: EM
authors.lastname: Reuter
authors.affiliation: Jacobs Center on Lifelong Learning and Institutional Change, Jacobs University, Bremen, Germany.|Department of Psychology & Methods, Jacobs University Bremen, Bremen, Germany; and.
authors.forename: Ben
authors.initials: B
authors.lastname: Godde
authors.affiliation: Aix-Marseille Université, Centre National de la Recherche Scientifique (CNRS), Institut des Sciences du Mouvement, Marseille, France.
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Temprado
authors.affiliation: Université Toulouse III-Paul Sabatier, CNRS, Centre de Recherche Cerveau et Cognition UMR 5549, Toulouse, France raoul.huys@cnrs.fr.
authors.forename: Raoul
authors.initials: R
authors.lastname: Huys
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D005260:Female; D006801:Humans; D007537:Isometric Contraction; D007858:Learning; D008297:Male; D008875:Middle Aged; D009048:Motor Skills; D018482:Muscle, Skeletal / Q000254:growth & development / Q000502:physiology
keywords: aging; drift-diffusion coefficients; dynamics; isometric force control; long-term practice