Effects of Object Processing on Numerosity Perception Across Development

The present study examined numerosity processing across development. Garner’s interference paradigm was used in Experiments 1 and 2 to test the abstractness of numerosity representations. We asked adults (N = 71) and 4-to 5-year-old children (N = 39) to perform dimensional matching tasks (either numerosity-based or object-based) with a concrete object array and we calculated redundancy gains and interference costs. In Experiment 1, across the age groups, gains and costs were observed in numerosity perception, but not in object perception. Experiment 2 showed that this asymmetrical integral relation is likely not due to a lack of processing time. These results call into question the abstract innate number system and imply that numerosity perception is context sensitive for both adults and children.