CHILDRENS AND ADULTS LEARNING OF A VISUOMANUAL COORDINATION - ROLE OF ONGOING VISUAL FEEDBACK AND OF SPATIAL ERRORS AS A FUNCTION OF AGE

The role of ongoing visual feedback and of spatial errors in learning a target-aimed task was investigated in 6-, 8-, and 11-yr.-old children, and young adults. In each of the four age groups, 16 subjects were randomly assigned to one of three conditions of learning (either with or without vision of the limb or with vision of final spatial error). All the subjects were tested without vision of the limb before and after the learning session. Before learning, directional bias was larger for 8-yr-old children and target undershooting was greater for adults. After learning with vision of final spatial error, amplitude and direction improved for all age groups. Nevertheless, directional accuracy during the learning session increased more slowly for children than for adults. After learning with vision of the limb, direction improved for 6- and 8-yr.-old children only, demonstrating a specific role of ongoing visual feedback during learning at these ages. Further, an analysis of movement paths suggests a poorer capability for integrating proprioception by children than by adults.