Children's development of reaching: temporal and spatial aspects of aimed whole-arm movements.
Age-related changes in movement time and spatial distribution of pointing errors were investigated using a whole-arm target-aimed task. 60 children (6 to 11 yr.) and 10 young adults were required to reach towards targets located on a vertical screen in four conditions: target lit for 4 sec. in light (1), in darkness (2), target lit for 200 msec. in light (3), in darkness (4). Accuracy was perfect in Conditions 1 and 2, with a significant increase of MT in Condition 2 between the ages 7 and 10. Accuracy decreased slightly in Condition 3 and strongly in Condition 4, despite a similar shortening of MT. In Condition 4 the subjects undershot the target position: horizontally from age 8 and vertically in all age groups, with an increase of vertical bias by girls at age 9. These results suggest age-related changes in computation of arm movement towards the target.
Fayt
C
C
Laboratory of Neurophysiology, University of Louvain, Brussels, Belgium.
Schepens
N
N
Minet
M
M
D000328:Adult; D001288:Attention; D002648:Child; D002657:Child Development; D005260:Female; D006801:Humans; D008297:Male; D009949:Orientation; D011597:Psychomotor Performance; D012016:Reference Values; D013998:Time Perception