ИСТИНА

Humans are equipped with the ability to estimate numerosity in both symbolic and nonsymbolic formats. Relations between cognitive functions and the development of symbolic and nonsymbolic magnitude representations were not studied well. It was demonstrated that FI or WM associated with accuracy of magnitude representations in both symbolic and nonsymbolic formats, but it is unclear in what extent growth in acuity of nonsymbolic and symbolic representations can be explained by growth in domain-general cognitive functions. In this study, we aimed to compare developmental changes in nonsymbolic and symbolic magnitude representations across the elementary school years. For this aim, we used a four-wave longitudinal study of schoolchildren in grades 1-4 in Russia and Kyrgyzstan (N= 490, mean age was 7.65 years at grade 1). The results of mixed-effects growth models revealed that growth in the precision of symbolic representations was larger than growth in nonsymbolic representation. Moreover, growth in the nonsymbolic representation was fully explained by growth in fluid intelligence (FI), visuospatial working memory (VSWM) and processing speed (PS) while growth in symbolic representation was independent on growth in domain-general functions. The analysis demonstrated that growth in nonsymbolic magnitude representation was significant only for pupils with a high level of FI or PS, whereas growth in precision of symbolic representations did not significantly vary across pupils with different levels of FI, PS or VSWM.