UBC Theses and Dissertations
Closed-loop control versus preprogrammed control in a self-paced and ballistic response Roy, Eric Alexander
The main purpose of this study was to determine the generality of the closed-loop theory and the preprogramming theory as an explanation for the learning and maintenance of performance in a highly practiced self-paced and ballistic response. The methodology used to investigate this problem involved comparing performance, following the withdrawal of knowledge of results, under changed or interrupted feedback conditions to a control condition in which feedback was the same as that in acquisition. Subsidiary problems involved 1) examining the effects of changing or interrupting feedback during KR withdrawal following low practice in acquisition and, 2) examining the differential effects of low and high practice in acquisition on performance in each response type during KR withdrawal under each of the three feedback conditions. The experimental task involved learning to move a cursor on a track from one end of the track to the other in 1.0 seconds. Two types of responses were used: 1) self-paced, in which the subject was permitted to hold on to the cursor for the entire length of the track and, 2) ballistic, in which the subject had to release the cursor after he moved it only about one sixth of the track distance. Sixty students of the University of British Columbia served as subjects. The results indicated that the preprogramming theory explained the learning and maintenance of performance in a highly practiced ballistic response, while the closed-loop theory was most applicable to the highly practiced self-paced response. Secondly, after 15 trials of practice in acquisition both response types were dependent on feedback, but the amount of feedback necessary was much less in the ballistic response than in the self-paced response. Thirdly, in the ballistic response, a comparison of performance in KR withdrawal following a small amount of practice in acquisition with that following a large amount of practice indicated that there was a transition from a primitive preprogramming mechanism which was somewhat dependent on feedback to a well developed preprogrammed mechanism which was not dependent on feedback. Finally, a closed-loop mechanism was suggested for the self-paced response following both small and large amounts of practice in acquisition.
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