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|Title:||The Effects of Variability of Practice on The Learning of a Motor Task|
|Author(s):||Givens, Michael Wayne|
|Department / Program:||Physical Education|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Abstract:||The focus of this research was directed toward an examination of the processes involved in the development of control of the force of muscular contractions, and the test of specific hypotheses concerning the kinds of experiences that facilitate the force-control learning process. The purpose of the research was to determine the effect that practicing a movement at a variety of load resistances, as compared to no variety, had on the performance of that movement at transfer to novel and non-novel load resistances.
Sixty male volunteer subjects performed unidirectional flexion, or extension, movements of the right forearm in a horizontal plane. The movement task was to move the forearm through 30(DEGREES) angular displacement to a time criterion of 300 milliseconds. Variety of practice was accomplished by selecting different levels of inertia to oppose the movement of the forearm. Dependent variables were time error scores and electromyographic activity of the muscles which were involved in the movement task. Subjects were given 99 trials to learn the movement task. Following the learning trials, selected trials were used to test the short-term retention of the muscle commands used to perform the task during the 99 learning trials. Analysis of variance and a priori planned comparisons were used to test statistical hypotheses concerning the effects of variability of practice. A Stepwise Multiple Regression analysis was used to search for unique relationships between the time error scores and electromyographic (EMG) activity of the muscles.
The results of this study indicated specific changes in the EMG activity that appeared to accompany improved performance of the movement task. The changes in the EMG signal were representative of modifications of the motor system's command signals to the musculature. It was found that at initial transfer to a non-level task (for the no-variability group) of the same movement class, no variability of training was better than variability of training provided the transfer task was outside the range of practice conditions for the variability group. If the transfer task was within the range of practice conditions for the variability groups, no differences in performance between the no-variability and variability groups were detected by the statistical test. It was found that at initial transfer to a novel task of the same movement class, variability of practice facilitates performance if the novel task resides within the range of practice conditions for the variability groups. At transfer to a novel task of a different movement class, performance was facilitated for those groups that had previously performed movements which required a similar strategy as the transfer task which involved a different movement class.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1980.
|Date Available in IDEALS:||2014-12-14|