Four-month-old infants extract ordinal information in number-based and size-based visual sequences, provided that magnitude changes involve increasing relations. Here the ontogenetic origins of ordinal processing were investigated between 2018 and 2022 by testing newborns' discrimination of reversal in numerosity (Experiment 1, N = 22 White, 11…

In quantity discrimination tasks, adults, infants and animals have been sometimes observed to process number only after all continuous variables, such as area or density, have been controlled for. This has been taken as evidence that processing number may be more cognitively demanding than processing continuous variables. We tested this hypothesis…

This study investigates the ability of 6-month-old infants to attend to the continuous properties of a set of discrete entities. Infants were habituated to dot arrays that were constant in cumulative surface area yet varied in number for small (less than 4) or large (greater than 3) sets. Results revealed that infants detected a 4-fold (but not…

Behavioral studies show that infants are capable of discriminating the number of objects or events in their environment, while also suggesting that number discrimination in infancy may be ratio-dependent. However, due to limitations of the dependent measures used with infant behavioral studies, the evidence for ratio dependence falls short of the…