Tracking the eyes to see what children remember

Relational memory is a canonical form of episodic memory known to rely on the hippocampus. Several lines of evidence suggest that relational memory has a developmental trajectory in which it is fragile, inflexible, and error-prone until around 6 years of age, which seems to mirror maturational changes in the morphology of the hippocampus. However, recent findings from Richmond and Nelson (2009) challenge this idea as they provide evidence suggestive of adult-like relational memory in 9-month-old infants. In this study the authors measured the eye movements of infants and showed that they preferentially gazed at correct, as opposed to incorrect, face-scene pairings at test. The goal of the present study was to evaluate the development of relational memory by assessing 4-year-olds using Richmond and Nelson's task and stimuli, but gathering two dependent measures of relational memory: overt response as well as eye movements. The results show that, overall, preferential looking at correct face-scene pairings was at chance; however, preferential looking was observed when the correct face-scene pair was later explicitly identified. Thus, while eye movements do index explicit memory in 4-year-olds, behavioural data are necessary to obtain a full picture of the development of relational memory in childhood.