Tracking with and without target in 6- to 15-year-old boys

It is well documented that, in adults, manual tracking of a visual periodic target is very accurate in a wide variety of experimental conditions. With children between 5 and 9 years of age, however, the response lags significantly behind the stimulus. The first study presented here attempts to described the acquisition of this skill by children between 9 and 15 years of age. Within this age span, adult proficiency in pursuing a rapid target was approached through an improvement in response synchronization. Yet adults were distinguishable from the oldest children by a fundamentally different mode of movement execution: The former maintained a smooth modulation of the proper motor pattern, whereas the latter relied mainly on corrections through visual feedback. The second experiment showed that these different perceptuomotor strategies may be related to the availability of a more accurate and stable motor pattern with age. Young children had difficulties reproducing the stimulus after it was withdrawn, with performance deteriorating as the trial progressed. The initial mismatch and the following drift tended to decrease with age, even though the oldest children's stationary performance was still not as consistent with the target motion as the adult response.