In their specialized schooling, blind children are now frequently presented with raised line figures and maps. However, there is still much to do in evaluating the cognitive effects of training using these displays. The purpose of this research is to determine if the level of expertise in the haptic exploration, and the perception of the raised line materials, may enhance blind people's spatial imagery. We have observed that in all the tasks in this study (mental rotation, mental spatial displacement and estimation of length tasks) the congenitally blind experts performed better than the early and late blind non-experts, and that the early blind experts performed even better than the late blind non-experts. These observations suggest that a high level of expertise in congenitally and early blind people may compensate for the impairment in spatial representation often resulting from lack of visual experience. (Contains 3 tables and 1 figure.)