Investigating the effects of marijuana on human psychological functioning, this study differs from previous research in two ways: 1) it is concerned with relatively complex cognitive processes; 2) it has a theoretical rationale. The general hypothesis of the study states that marijuana will impair its user's ability to form and use abstract…

This study examines the relationship between development of a child's ability to coordinate perspective and his ability to conceptualize spatial relations on a map. One hundred and four school children from inner city, urban fringe, and suburban schools, grades K-6, were administered a Test of Coordination of Perspectives and a Test of Map…

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…