Judgment of rectangular areas in children blind from birth

Many studies in the framework of information integration theory have been dedicated to the judgment of rectangular areas in young sighted individuals. Many integration rules have been proposed (e.g., multiplicative, additive, maximum extent, relative centration, length only, width only) and tested, but uncertainties persist concerning the fine integration process. In order to shed light on this process, we turned to a population of young children blind from birth, 6 to 8 years of age, and examined in detail their gestural strategies when placed in an area evaluation situation. The following prudent conclusions appear justified: (a) that the strategy of acquisition and integration of information was a very markedly dimensional strategy; (b) that this strategy could be accompanied by attempted tactile scanning of the two dimensions; and (c) that the integration process obeyed an additive type rule, with greater weight attributed to the larger dimension (relative centration rule).