Authors: Tyler Cluff Jason Boulet Ramesh Balasubramaniam
Publish Date: 2011/06/26
Volume: 213, Issue: 1, Pages: 15-25
Abstract
Theories of motor learning argue that the acquisition of novel motor skills requires a taskspecific organization of sensory and motor subsystems We examined taskspecific coupling between motor subsystems as subjects learned a novel stickbalancing task We focused on learninginduced changes in finger movements and body sway and investigated the effect of practice on their coupling Eight subjects practiced balancing a cylindrical wooden stick for 30 min a day during a 20 day learning period Finger movements and center of pressure trajectories were recorded in every fifth practice session 4 in total using a ten camera VICON motion capture system interfaced with two force platforms Motor learning was quantified using average balancing trial lengths which increased with practice and confirmed that subjects learned the task Nonlinear time series and phase space reconstruction methods were subsequently used to investigate changes in the spatiotemporal properties of finger movements body sway and their progressive coupling Systematic increases in subsystem coupling were observed despite reduced autocorrelation and differences in the temporal properties of center of pressure and finger trajectories The average duration of these coupled trajectories increased systematically across the learning period In short the abrupt transition between coupled and decoupled subsystem dynamics suggested that stick balancing is regulated by a hierarchical control mechanism that switches from collective to independent control of the finger and center of pressure In addition to traditional measures of motor performance dynamical analyses revealed changes in motor subsystem organization that occurred when subjects learned a novel stickbalancing task
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