The goal of this study is to determine the effect of training in figural representations of numerical and geometrical transformations. Subjects were 6 and 7 years old, and the problem used is usually grasped at 10 or 11 years. The general hypothesis is that mental imagery, or figurative knowledge, structures "operatoire" reasoning and is not merely an auxiliary process, as Piaget and Inhelder suggested. Results show that children made important progress during and after the training phase if and when they formed correct visual images. By contrast, children whose imagery was poorly elaborated did not progress. As expected, visual imagery seems to play a necessary and structuring role for the development of "operatoire" reasoning.
mental imagery; operatoire reasoning; figurative training
