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.     

Children's use of landmarks: implications for modularity theory

Previous studies have shown that disoriented children use the geometric features of the environment to reorient, but the results have not consistently demonstrated whether children can combine such information with landmark information. Results indicating that they cannot suggest the existence of a geometric module for reorientation. However, results indicating that children can use geometric information in combination with landmark information challenge the modularity interpretation. An uncontrolled variable in the studies yielding conflicting results has been the size of the experimental space. In the present studies, which tested young children in spaces of two different sizes, the size of the space affected their ability to use available landmark information. In the small space, the children did not use the landmark to reorient, but in the large space they did. The ability of children to use landmarks in combination with geometric information raises important questions about the existence of an encapsulated geometric module.     

Change and continuity in early spatial development: claiming the “radical middle”

Debate over change and continuity in cognitive development has revolved around questions of qualitative transitions versus quantitative and incremental improvement. Piaget’s stage theory is the best-known example of a change/qualitative transition approach, while both nativism and empiricism have, for very different reasons, taken a continuity/quantitative increment stance. Recent proposals have, however, attempted to transcend this stark dichotomy, in a move that can be termed claiming the “radical middle.” This paper presents two examples of developmental analyses in spatial development. These two transitions are characterizable as either qualitative or quantitative, but are best thought of as both. A position of this kind allows for much more precise answers to practical questions about issues such as sensitive periods than would otherwise be possible.     

Potentiation in young infants: The origin of the prior knowledge effect?

In two experiments with 6-month-old infants, we found that prior learning of an operant task (remembered for 2 weeks) mediated new learning of a modeling event (remembered for only 1 day) and increased its recall. Infants first learned to associate lever pressing with moving a toy train housed in a large box. One or 2 weeks later, three target actions were modeled on a hand puppet while the train box (a retrieval cue) was in view. Merely retrieving the train memory strengthened it, and simultaneously pairing its retrieved memory with the modeled actions potentiated their learning and recall. When paired 1 week later, deferred imitation increased from 1 day to 4 weeks; when paired 2 weeks later, it increased from 1 day to 6 weeks. The striking parallels between potentiated learning in infants and the prior knowledge effect in adults suggests that the prior knowledge effect originates in early infancy.