Early Subitizing Development: The Role of Visuospatial Working Memory

The present study explored enumeration processes, serial counting and subitizing, in early childhood. Subitizing is a fast and accurate assessment of small quantities. Early quantitative processing is built off of a “parallel individuation” system, a domain-general, visuospatial system that allows infants to track small sets of objects. This system creates a precise mental model of every object in a small set, similar to subitizing. Subitizing ability helps children to acquire mature symbolic representation of numeral, and deficits in enumeration processes is associate to math disabilities. However, the role of development in enumeration processes and the role of visuospatial working memory is enumeration processes is largely unknown. Hence, in the present study, we tested visuospatial working memory’s role in subitizing development in preschoolers. We tested 3 to 5-year-old’s performance in enumeration and visuospatial working memory tasks. Performance in the subitizing range (one to four items) related to individual differences in visuospatial working memory and age, while performance for greater numericities in the serial counting range did not. Interestingly, controlling for visuospatial working memory span reduced the developmental effect of subitizing, suggesting that both visuospatial working memory and age can affect individual differences in subitizing in young children, which has implications for early childhood education.