How Do Symbolic and Non-Symbolic Spatial-Numerical Associations Develop? Evidence from the Parity Judgment Task and the Magnitude Comparison Task

Although the SNARC effects in symbolic numerals and non-symbolic numerosity have been observed in different studies, little is known about their developmental trajectory and potential relationship. The present study aims to explore the development of the symbolic and non-symbolic SNARC effects across different age groups, and further examine the relationship between these two SNARC effects. Experiment 1 measured 36 6-to-7-year-old children, 59 7-to-8-year-old children, 69 8-to-9-year-old children, and 31 adults from China using parity judgment tasks. The results showed that the non-symbolic SNARC effect emerged in all age groups. While, the symbolic SNARC effect only emerged in 8-to-9-year-old children as well as adults. Experiment 2 measured 53 6-to-7-year-old children, 83 7-to-8-year-old children, 85 8-to-9-year-old children, as well as 31 adults from China with the magnitude comparison tasks. We found that both the symbolic and non-symbolic SNARC effects emerged in 7-to-8-year-old children, 8-to-9-year-old children as well as adults. Both experiments showed that for children and adults with significant symbolic SNARC effects and non-symbolic SNARC effects, the size of these two SNARC effects did not show significant differences. In addition, these two SNARC effects were both dissociated in two types of tasks. These findings are important for clarifying how symbolic and non-symbolic spatial-numerical associations develop.