Year of Award


Document Type


Degree Type

Master of Arts (MA)

Department or School/College

Department of Psychology

Committee Chair

Laurence H. Berger


Memory., Motor learning.


University of Montana


Historically in motor skills research, there has been an emphasis on acquisition and limited work on retention. Recent reviews by Adams (1987) and Schendel, Shields, and Katz (1978) summarize the empirical retention research as vague, qualitative ’'principles," which do not integrate retention results with acquisition phenomena. The present study describes pursuit rotor retention over a much longer period than any previous research. Thirteen subjects who had taken part in an earlier rotary pursuit acquisition study were retested an average of 15.5 years after original practice. Matched age control groups were given the same amount of acquisition practice and retested after a one-week retention interval, so that all subjects had the same amount of total practice but differed in length of retention interval. The results provided data for testing and revising two principles of retention: (i) forgetting increases as a positive function of the retention interval; (ii) relearning is more rapid than the original learning. It was found that subjects retested after a 15.5 year period of no practice perform much like naive subjects, with essentially a slow, linear increase in performance during initial continuous practice. After the first rest, performance jumps in one large increment up to the performance pattern and level of the control groups, but shows more rapid decrement in the later parts of the practice period. A reinterpretation of these and other retention phenomena as schedule-induced differences in performance was made, showing that forgetting is simply the decay in reminiscence over long periods of time and not the decay of learning. Apparent losses in performance upon initial retest measure merely the predictable changes in reminiscence as its reappearance is depressed by the continuous or highly massed retest conditions, and rapid "relearning" to previous acquisition levels is simply the predictable reappearance of reminiscence after the first postrest practice during retesting. Four principles of pursuit rotor performance are stated and used to describe retention phenomena in terms of acquisition phenomena. Finally, some preliminary suggestions are made for the extention of Kimble's theory of skill acquisition.



© Copyright 1988 Douglas Ammons