The cues that infants use to distinguish discontinuous quantities: Evidence using a shift-rate recovery paradigm

A novel experimental method, shift-rate recovery, was developed and used in a series of three experiments. These examined the extent to which 6-month- old infants (N= 131) find perceptual cues such as density and length useful in the discrimination of linearly arranged sets containing large numbers o f objects. Results showed that infants discriminated between arrays that di ffer in number and density, with length held constant, when the arrays were presented either simultaneously or successively. On the other hand, infant s discriminated only between arrays that differ in number and length, with density held constant, when the arrays were presented simultaneously. Infan ts were, however, able to perform a successive length discrimination when t he arrays were continuous rather than consisting of discrete items. These f indings support the conclusion that infants are able to discriminate betwee n large number sets by relying on absolute cues such as density (but not le ngth) and on relative cues such as optical one-to-one correspondence.