The purpose of this study was to attempt to train the horizontality concept in a group of first graders who were non-operational on the horizontality concept but transitional on what Piaget has termed the precursor concepts of distance and length conservation. There were two groups of subjects (training and control), all of whom had failed a…

Examined perception of object unity in partial occlusion in 72 infants. Recorded how long subjects looked at a display of complete and incomplete rods. In test and control conditions, infants looked longer at broken rods than at complete rods, suggesting that infants' cognitive, visual, or attentional skills may be insufficient to support…

Educational implications and symptoms are described for learning disorders, the disruption in the processing of information within the central nervous system caused by brain damage, emotional disturbance, or inadequate presentation of learning experiences. Developmental sequences, developmental progression, and restoration of development are…