Resumen de Toddlers' cognition of adding and subtracting objects in action and in perception
Jonas Langer, Peter Gillette, Rosa I. Arriaga
A first experiment tested infants’ perceptual discrimination between correct and incorrect adding and subtracting objects with a standardized violation-of-expectation procedure. Eleven-, 16- and 21-month-olds did not look longer at incorrect (one object) than at correct (two objects) results of adding one object to another, nor at incorrect (two objects) than at correct (one object) results of subtracting one object from two. A second experiment tested 21-month-olds’ sensorimotor production of addition and subtraction results using a search-for-objects procedure. They already searched correctly for two objects when one object is added to another and for one object when one is subtracted from two objects. These findings support the constructivist hypothesis that infants’ active sensorimotor production may develop before their reactive perceptual discrimination of adding and subtracting objects.
