Robert Kerr

Manual asymmetries within the performance of a complex motor task

Abstract There appears to be some controversy in the literature as to whether the transfer of learning is greatest from the non-preferred to the preferred side or to the reverse. The purpose of this present study was to examine manual asymmetrics using a discrete pursuit tracking task which measures the speed and accuracy of movement. Based on the conceptual framework of Schmidts theory of generalized motor programs it was proposed that initial practice with the preferred hand would provide better quality feedback regarding response specifications and sensory consequences and thus transfer of learning should be greater from the preferred to the non-preferred hand. A total of 20 subjects participated in the study and they were randomly assigned to two treatment conditions: preferred to non-preferred and non-preferred to preferred. Each subject completed a total of 12 trials in which each trial consisted of 100 target presentations. Eight trials were performed with the first hand, and four trials with the second hand as designated by treatment group. The results indicated that there were no significant differences between the groups except for movements without overshoots. The findings appear to provide some support to the hypothesis that the preferred to non-preferred group developed a better model of the task as a result of the initial practice.

Practice variability and longer and short retention intervals.

This experiment compared the effect of different practice schedules on distance and direction errors in a blindfolded two-dimensional movement. The three experimental groups, (a) criterion target only, (b) varied targets (not criterion), (c) single target (not criterion) and one control group (rested), were tested immediately after the “practice” session without knowledge of results and were tested again after a 1-wk. retention interval. The distance data demonstrated little difference among the three experimental groups, but all three groups were significantly better than the control group. However, there was little difference in errors of direction among the groups. While the data for distance support a schema interpretation of movement control, the data for direction appear to reflect the concept of a visual-spatial map being used to guide movements.

Motor and Verbal Learning of Movements

When teaching any skill there is always the implication that the learner can translate verbal instructions and corrections into movements and express verbally problems with their own movements. The complexity (in terms of the number of variables) of most motor skills requires the learner to handle several bits of information. Children were tested for verbal recall or recall by demonstration (motor) of a sequence of movements previously presented by either method. Analysis suggested that subjects who were required to translate the information between modes evidenced better retention.

COMMUNICATION THROUGH PHYSICAL ACTIVITY FOR LEARNING DISABLED CHILDREN

To measure the extent to which an integrated program of motor and cognitive tasks might enhance the learning disabled childrens motor and basic cognitive skills, a treated group of 8 had three ½-hr. sessions per week for 6 mo. 8 control subjects continued regular physical education and reading programs with their classroom teacher. All subjects were tested before and after 6 mo. Over-all the treated group showed greater improvement on tests of both motor and cognitive skills than the control group. This study suggests a physical activity program can influence basic cognitive skills as well as motor skills.

Aspects of Psychomotor Performance in the Recovery from Right Hemisphere Lesions

The ability to learn and perform a psychomotor task (pursuit tracking task) of ten subjects who had sustained right hemisphere lesions (RHL) was compared to ten healthy individuals matched for age and gender. The task required subjects to react and move quickly, varying both the distance to be moved and the choice of movement direction. All subjects completed 1200 responses across two testing sessions. Results indicated that while the RHL group was able to ‘learn’ the task as well as the Control group, they were slower at correcting unanticipated movement errors. In addition, the RHL group did not respond to changes in the probable direction of the next movement in the same manner as the Control group and, in fact, appeared unaware of changes in the probability of movement direction.

Independent Living and Psychomotor Performance

While the majority of seniors live outside of institutions, many live in seniors apartment buildings rather than in single family dwellings. MacPherson (1983) suggested that not maintaining an independent living style may have some negative consequences for seniors. The question asked was whether differences in lifestyle arising from the nature of the residence were associated with measures of psychomotor performance. Some 36 seniors, average age approximately 68 yrs., all in good health, completed 800 responses on a discrete pursuit tracking task which emphasized response speed and accuracy. Significant differences in performance were noted for both RT and speed of movement. Overall, seniors living independently, either in urban or rural areas, responded faster than seniors living in seniors apartment buildings. The data do not imply a causal relationship, however, they do suggest that psychomotor variables are relevant factors to consider in regard to differing living styles.

Movement as a creative form: Comment on S. Higgins' ‘Movement as an emergent form: its structural limits’

Abstract ‘Movement as an emergent form’ (Higgins 1985) presents an eloquent argument for considering the dynamic interaction between a system and its surround. The purpose of this paper is to argue that where human movement is concerned the system, being imperfect, is less bounded by its environment and more guided by its ‘internal’ creative talent.