A DAY AT DEVELOPMENTAL DOWNS: SPORTSCAST FOR RACE #2 - NEO-PIAGETIAN THEORIES OF COGNITIVE DEVELOPMENT

This article discusses the neo-Piagetian theories of cognitive development proposed by Robbie Case, Andreas Demetriou and Anastasia Efklides, Kurt Fischer, Jeffrey Farrar, Graeme Halford, Juan Pascual-Leone, Michael Shayer, and Robert Siegler. Each theory is discussed in terms of its basic assumptions, and propositions regarding structure, process, novelty and automatization, context, and mechanisms of development. Then some general conclusions are drawn about the enterprise of neo-Piagetian theorizing as a whole.     

Quantitative assessment of infant reaching movements

We have identified a fundamental property of human motor behavior as a tight coupling of the curvature-speed relationship in the reaching movements of 5- to 9-month-old infants. This relationship termed a movement unit, occurs regardless of the distance of duration of the reach and in spite of the developmental change that occurs in grasping during this period. Movement unit durations are tightly clustered around 200 ms regardless of overall duration or distance or the position of the unit in the reach. The curvature-speed coupling has been identified by others in adult reaching and handwriting. Models of biological motor control must account for this invariant relationship.