The development of children's mental tracking strategies on a rotation task

In two experiments, 5- to 13-year-old children were required to mentally track the rotation of a pointer around a circular backdrop, and to indicate the pointer's imagined position on the backdrop at the sound of a signal. In Experiment 1, children imagined the pointer rotate around its end point. In Experiment 2, children imagined the pointer rotate around its midpoint, and indicated the position of one of its two ends at the time of the signal. The end to be indicated was not specified by the experimenter until the time of the signal. Thus, children were required to use an imaging strategy that could keep track of the changing positions of both ends of the pointer. In both experiments, children older than 8 years of age generated linear distance X time functions indicating mental tracking, but younger children did not. In Experiment 2, the proportions of children at each grade level using holistic or part-to-part strategies to mentally track the pointer were comparable, as were mental tracking rates. The results were discussed in relation to both recent research on children's counting, and Piagetian and information-processing views of mental imagery development.