DEVELOPMENTAL DIFFERENCES IN THE PROCESSING OF AFFERENT INFORMATION FOR MOTOR CONTROL

Chicoine, Lassonde, and Proteau (1992) recently proposed that young ch ildren processed independently from each other the different sources o f sensory information available for controlling an aiming movement, bu t that maturation would result in the different sources of afferent in formation being processed intermodally. In this study we tested an alt ernative interpretation to that, of Chicoine et al. Specifically, beca use of the limited time in which the participants of their study had t o complete their movement, their results might indicate that the young er participants used an open-looped mode of control. To test this poss ibility, children of different ages, as well as adults, practiced a co mplex, multisegment, aiming task in full vision prior to being submitt ed to a no-vision transfer condition. Participants of all age-groups h ad to complete the task in either 500 ms or 1,000 ms. Results indicate d that the withdrawal of visual information in transfer caused larger aiming error for the adults than the younger children. These results r eplicated those of Chicoine et al. and suggest that the different sour ces of sensory information available for ''online'' movement control a re processed largely independently from each other in young children b ut not in adults.