Visual attention to meaningful stimuli by 1- to 3-year olds: implications for the measurement of memory

The visual recognition memory (VRM) paradigm has been widely used to measure memory during infancy and early childhood; it has also been used to study memory in human and nonhuman adults. Typically, participants are familiarized with stimuli that have no special significance to them. Under these conditions, greater attention to the novel stimulus during the test (i.e., novelty preference) is used as the primary index of memory. Here, we took a novel approach to the VRM paradigm and tested 1-, 2-, and 3-year olds using photos of meaningful stimuli that were drawn from the participants' own environment (e.g., photos of their mother, father, siblings, house). We also compared their performance to that of participants of the same age who were tested in an explicit pointing version of the VRM task. Two- and 3-year olds exhibited a strong familiarity preference for some, but not all, of the meaningful stimuli; 1-year olds did not. At no age did participants exhibit the kind of novelty preference that is commonly used to define memory in the VRM task. Furthermore, when compared to pointing, looking measures provided a rough approximation of recognition memory, but in some instances, the looking measure underestimated retention. The use of meaningful stimuli raise important questions about the way in which visual attention is interpreted in the VRM paradigm, and may provide new opportunities to measure memory during infancy and early childhood.