in this paper we address the importance of imagination in development and focus on play as an especially privileged instance in this process. The formative role ascribed to this activity is often small, and it tends to be treated in a very ambiguous way in educational work. This problem is magnified when mental deficiency is involved, due to the added discredit of the child's possibilities. Based on the historical-cultural perspective we carried out a study on the play of twelve subjects, 4 to 6 year-old, who attended a special institution. Most of them had deficits in the areas of cognition and language; some also presented serious motor limitations. The objective was to investigate the relation between the mediation of others - adults and peers - and the child's imaginative actions, concerning his ability to transcend the immediate perceptual field and to compose make-believe sequences. The field work consisted of weekly sessions of free play, over a seven month period. The activities were video recorded, and the analyses were guided by a microgenetic approach. The findings show that, when left to their own resources, the subjects present a low inclination to join in collective play and to share in dialogues. However, depending on the forms of mediation within the group, they can engage in relatively complex imaginary situations, with characteristics that suggest contributions to intellectual development, in the comprehension of the cultural context, as well as to the emergence of creative elaborations about the world.
mental deficiency; imaginary process; social cultural mediation