Measuring the Size of Working Memory in Very Young Children: The Imitation Sorting Task

Abstract

Development of working memory in the transitional period from infancy to preschool years was investigated from a neo-Piagetian perspective. A new task, the Imitation Sorting Task, was specifically designed for this purpose. The task involves a game of imitation. An increasing number of disparate objects are sorted into two containers and the child is asked to reproduce each demonstrated sorting. The number of objects in the largest set that the child can successfully sort in imitation determines the child's score on the task. The task was administered three times to children from 12 to 36 months of age. Scores increased in a linear fashion with age in all three administrations. Upon retesting within a few weeks after the original administration, children's score and rank remained very similar. Their score increased at the follow-up after 6 months, but their rank still remained similar to their original rank. The age-related increase in the scores appears to be about one unit every six months in this age range.