Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)


As children mature through the childhood years, motor performance increases in a relatively linear way. This increase in performance is frequently attributed to physical growth factors such as increased height, weight and strength. However, cognitive factors in memory also develop and affect the planning and control of movement. The purpose of these three experiments was to evaluate the developmental increase in strategy use for planning movements and to determine if the motor performance of younger children could be enhanced by inducing strategy use that does not occur spontaneously. The effects of subject selected (preselected) or experimenter selected (constrained) movements was investigated relative to age level and strategy use. In all three experiments, subjects were selected from three age levels, 7 and 11 years and adults, based upon the predicted ages for the normal appearance of spontaneous strategy use. A total of 300 female subjects (100 at each age level) was used, 120 each in Experiments 1 and 2 and 60 in Experiment 3. Experiments 1 and 2 involved the same factors, age, strategy and pre-selected/constrained condition. The difference was 1 utilized a laboratory-controlled linear positioning task, 2 used a field task of jogging for distance. The results from 1 and 2 were very consistent. The more interesting data from these two experiments were the interaction between the spontaneous development of strategy use with increased age and the success with which strategy use could be induced by training for children. When trained to use a mature adult-like strategy, 7 and 11 year old children performed as accurately ( CE ) as adults in making positional and distance judgments. The younger children were more variable (band width of the memory trace was wider, VE) than the adults. The increased variability was caused by the inconsistency of strategy application. Elevated probe RT during planning under strategic conditions supported the fact that increased attention was required when compared to situations in which planning was not forced. Experiment 3, using the velocity task of throwing, did not support the findings when performance outcome was analyzed. The probe reaction time data did support the concept of increased effort for less meaningful movements. Rapid velocity tasks appear to be less open for strategic intervention to improve performance. Conclusions support the value of strategic intervention in reducing the age differences for recalling location and distance information from motor tasks which are slower, prolonged movements. The value of this memory development mnemonic generalizes from a controlled laboratory positioning task to the more ecologically valid task of reproducing the distance jogged. The strategic intervention did not generalize to a more rapid velocity movement, throwing.