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Abstract:
Abstract: Speed and spatial accuracy of cyclically drawn
simple planar geometrical patterns were studied. A total 37
right-handed subjects of different ages drew vertical and
horizontal dashes, circle, and square without seeing a movement
trace. Mean cycle duration and spatial accuracy index of digitally
recorded movements were analyzed against age (5 y.o., 7 y.o., 11
y.o., adults), tempo (as fast as possible (AFAP) vs. preferable),
hand (right vs. left), and imposed mechanical constraints
(wrist-elbow vs. elbow-shoulder movements). Movement speed
increased with age in all conditions with abrupt speed-up occurring
between ages of 5 and 7 years whereas spatial accuracy increased
90Aalmost lenearly with age. The right hand showed a considerable
superiority in speed over the left hand in all ages under AFAP
condition but not at preferable tempo. The right hand was
consistently more accurate than the left hand, this effect being
most pronounced for wrist-elbow movements. Wrist-elbow movements
didn't differ in speed from elbow-shoulder movements for either age
group under AFAP condition. At preferable tempo, proximal movements
were faster than distal movements in all groups except for adults
where no such a difference was found. Wrist-elbow movements were
more accurate than elbow-shoulder movements in all age groups
except for 5-year old children who showed an opposite pattern. The
results obtained are discussed in terms of different levels of
sensorimotor integration.
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