title: S-shaped motor learning and nonequilibrium phase transitions.
abstract: S-Shaped change in performance outcome has long been considered to be a pathway of motor learning, but there is little or no evidence for it. The experiment investigated the hypothesis that S-shaped motor learning as reflected in the task outcome is a product of a transition in the movement coordination dynamics as a function of practice acting as a control parameter. Young adult participants practiced the roller ball task that required learning the transition of a coordination mode to preserve and enhance the motion of a rotating ball to transition from task failure to success. There were 50 practice trials per day for as many practice days (3-20) as required for each participant to reach the task criterion of success that was followed 1 week later by a retention test. All participants improved their task performance with practice but there were subgroups of patterns of change including S-shaped learning. The enhanced variability during the transition supported the interpretation that the S-shaped learning outcome is reflective of a saddle-node bifurcation or first-order nonequilibrium transition. The learning of a new pattern of movement coordination is a different process from learning to scale an already producible coordination mode to new task demands.
authors: Department of Athletic Performance, National Taiwan Normal University.
authors: Yeou-Teh
authors: YT
authors: Liu
authors: Department of Kinesiology, The Pennsylvania State University.
authors: Karl M
authors: KM
authors: Newell
mesh_terms: D001288:Attention; D006801:Humans; D009048:Motor Skills; D011214:Practice, Psychological; D012153:Retention, Psychology