The Effect Of Visual Perturbation On Motor Control And Learning Of Children And Adults In Two-Segment Arm Movements

Objective: The development of the prefrontal regions lags behind subcortical regions during the first 20 years of life.This notion has been raised to explain the behaviours of children such as risk taking,sensation seeking and heightened emotional reactivity.In this study,we examined the developmental differences in motor control and learning of a two-segment movement.We hope to provide more research evidence on the characteristics and laws of children’s neurological and behavioral development from the perspective of motor behaviour.Methods: One hundred and five participants(53 female)were divided into three age groups(7 to 8 years,9 to 10 years and 19 to 27 years).They performed a two-segment movement task in four conditions(full vision,fully disturbed vision,disturbed vision in the first movement segment and disturbed vision in the second movement segment).We analyzed the accuracy,overall movement time,movement time of each segment,the percentage of primary sub-movement and normalised jerk with multivariate mixed analysis of variance.Results: The results for movement accuracy and overall movement time show that children,especially younger children,are more susceptible to visual perturbations than adults.The adults’ movement time in one of the movement segments could be increased by disturbing the vision of the other movement segment.The children’s movement time for the second movement segment increased when their vision of the first movement segment was disturbed.Disturbing the vision of the first movement segment decreased the percentage of central control of the second movement in younger children,but not in the other two age groups.The children’s normalised jerk was more easily increased by visual perturbations.The children showed greater improvement after practice in the conditions of partial vision disturbance.As the participants’ age increased,practice tended to improve their feedforward motor control rather than their feedback motor control.Conclusions: These results suggest that children’s central movement control improves with age and practice.From the findings of this study,we can get some inspiration and guidance on practical teaching,training and rehabilitation work.For example,when teaching or training for children,we are better to use as much visual stimuli as possible,and control the difficulty of the tasks to help children achieve better learning effects.