title: Task goals and change in dynamical degrees of freedom with motor learning.
abstract: In this article, the authors examined the hypothesis that the direction of the change (increase or decrease) in the dynamical degrees of freedom (dimension) regulated as a function of motor learning is task-dependent. Adult participants learned 1 of 2 isometric force-production tasks (Experiment 1: constant force output; Experiment 2: sinusoidal force output) over 5 days of practice and a 6th day with augmented information withdrawal. The results showed that over practice, the task goal induced either an increase (Experiment 1) or a decrease (Experiment 2) in the dimension of force output as performance error was reduced. These findings support the proposition that the observed increase or decrease in dimension with learning is dependent on both the intrinsic dynamics of the system and the short-term change required to realize the task goal.
authors.affiliation: Department of Kinesiology, College of Health and Human Development, Pennsylvania State University, University Park 16802, USA. kmn1@psu.edu
authors.forename: Karl M
authors.initials: KM
authors.lastname: Newell
authors.forename: Michael P
authors.initials: MP
authors.lastname: Broderick
authors.forename: Katherine M
authors.initials: KM
authors.lastname: Deutsch
authors.forename: Andrew B
authors.initials: AB
authors.lastname: Slifkin
mesh_terms: D000222:Adaptation, Physiological; D000223:Adaptation, Psychological; D000328:Adult; D006040:Goals; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D007699:Kinesthesis / Q000502:physiology; D007858:Learning / Q000502:physiology*; D008875:Middle Aged; D009048:Motor Skills / Q000502:physiology*; D011214:Practice, Psychological; D011340:Problem Solving / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D011601:Psychophysics; D011603:Psychophysiology