Infants form associations between memory representations of stimuli that are absent.

Traditional models of learning assume that an association can be formed only between cues that are physically present. Here, we report that when two objects that had never appeared together were simultaneously activated in memory, young human infants associated the representations of those objects. Neither object was physically present at the time the association was formed. The association remained latent for up to 2 weeks, when the infants used it to perform a deferred imitation task. These findings reveal that what infants merely see "brings to mind" what they saw before and combines it in new ways. In addition to challenging a fundamental tenet of classic learning models, these findings have major theoretical and practical implications for early cognitive development. Every day, in the same manner, young infants probably form numerous associations between activated memories of objects that are physically absent, creating a potential knowledge base of untold dimensions.