The study examined the effectiveness of enhancing perceptual differentiation in the training of four developmentally delayed preschool children who were so low-functioning that they did not demonstrate oddity responding (ability to choose one distinct stimulus from a group of identical stimuli). Instead of the Arabic numerals used in the original…

A two-phased training study attempted (1) to accelerate the rate at which a total of 8 severely and profoundly retarded children (mean age 57 months) developed the Piagetian concept of object permanence and (2) to demonstrate generalization of the higher performance on object permanence scale to other scales of sensorimotor intelligence and to the…