How to rapidly construct a spatial–numerical representation in preliterate children (at least temporarily)

Spatial processing of numbers has emerged as one of the basic properties of humans’ mathematical thinking. However, how and when number–space relations develop is a highly contested issue. One dominant view has been that a link between numbers and left/right spatial directions is constructed based on directional experience associated with reading and writing. However, some early forms of a number–space link have been observed in preschool children who cannot yet read and write. As literacy experience is evidently not necessary for number–space effects, we are searching for other potential sources of this association. Here we propose and test a hypothesis that the number–space link can be quickly constructed in preschool children's cognition on the basis of spatially oriented visuo‐motor activities. We trained 3‐ and 4‐year‐old children with a non‐numerical spatial movement task (left‐to‐right or right‐to‐left), where via touch screen children had to move a frog across a pond. After the training, children had to perform a numerosity comparison task. After left‐to‐right training, we observed a SNARC‐like effect (reactions to smaller numbers were faster on the left side, and reactions to larger numbers on the right side), and after right‐to‐left training a reverse effect. These results are the first to show a causal link between visuo‐motor activities and number–space associations in children before they learn to read and write. We argue that simple activities, such as manual games, dominant in a given society, might shape number–space associations in children in a way similar to lifelong reading training.