Developmental changes in numerosity and area perception in school-age children

Humans can quickly estimate the quantity of objects in their environment through the Approximate Number System (ANS). However, the developmental trajectories of numerical and spatial perception in school-aged children are not well understood. This study aimed to address this issue by examining the performance of 7-year-olds, 9-year-olds, and 11-year-olds in the dot-number and dot-area tasks. In each trial, participants were presented with pairs of dots array simultaneously and were asked to indicate which array had a greater quantity of dots in the dot-number task, and which array had a larger overall area of dots in the dot-area task. We manipulated number cues and area cues of the dots array in these two tasks, creating three different relationships between dot-number and dot-area: congruent, neutral, and incongruent. Our results showed school-aged children's ability to estimate numerosity improved significantly after the age of 7, with no apparent improvement observed between the ages of 9 and 11. This indicates a marked growth in acuity in the perception of numerical quantities. Conversely, the capacity to estimate area showed consistent stability across the various age groups examined. Additionally, our results demonstrated a pronounced difficulty among participants in ignoring numerical cues when assessing dot quantity or dot area, as opposed to non-numerical cues. This highlights a preferential sensitivity to numerical information in cognitive processing. These findings provide valuable insights into the cognitive development underlying quantity perception and may offer practical guidance for educational practices.