The Constructivist Learning Architecture (CLA) is a model of infant cognitive development. This model is based on a constructivist information-processing approach to cognitive development, which postulates that Piagetic stages of development are a characteristic of infants' learning capabilities. The claim is that a single information processing mechanism can account for developmental change throughout development and across domain. CLA is implemented using a hierarchy of Self-Organizing Maps, in which higher-level maps learn patterns of activation in lower-level maps.