The Role of Representational Flexibility in Toddlers' Manual Search

In the model room task, children watch as a miniature toy is hidden somewhere in a scale model of a room and are asked to find the larger version of the toy in the corresponding place in the actual room. Previous work has shown that children under age three often perform very poorly on this task. One prominent theory for their failure is that they lack the ability to understand the model as both a physical object and as a symbolic representation of the larger room. An alternative hypothesis is that they need to overcome weak, competing representations of where the object was on a previous trial, and where it is in the present trial, in order to succeed in their search. Children aged 33-39 months were tested on measures of inhibitory control, cognitive flexibility, recognition memory, and receptive vocabulary, as well as the model room task. Results showed that performance on the model room task was not predicted by measures of inhibitory control, cognitive flexibility or vocabulary, but was predicted by performance on the Delayed Recognition Span Test (DRST), a measure of recognition memory. These findings lend support to the theory of competing representations. Given the predictive nature of the recognition memory task and the task's sensitivity to lesions in the hippocampus, implications for the development of the hippocampus and its role in success on the model room task are discussed.