Neuropsychological Insights into the Meaning of Object Concept Development
Adele Diamond University of Pennsylvania
I propose that infants know a good deal more about objects than Piaget gave them credit for knowing. For Piaget, many of the developments between 5 and 12 months of age concerned the elaboration of the concept of the object and the concept of space. The thesis of this chapter is (a) that what emerges between 5 and 12 months is, instead, the ability to demonstrate an understanding of these concepts, the understanding already having been present, and (b) that these behavioral developments between 5 and 12 months are intimately tied to maturation of frontal cortex.
If infants understand the object concept and spatial relationships, why can't they demonstrate this in their behavior? There appear to be two reasons. First, behavioral predispositions get in the way. Infants must be able to inhibit these action tendencies if they are to demonstrate what they know. Second, the demonstrations that Piaget required of infants often involve relating two actions together in a sequence or relating information over a separation in space or time. These inhibitory and relational abilities are not in place early in the first year. Frontal cortex and its network of neural interconnections must reach a certain level of maturity before these abilities begin to appear.
Cognitive development can be conceived of, not only as the progressive acquisition of knowledge, but also as the enhanced inhibition of reactions that get in the way of demonstrating knowledge that is already present. Reflexes of the hand, which are invaluable aids during the first months of life, must be