The Developing Mental Number Line: Does Its Directionality Relate to 5- to 7-Year-Old Children’s Mathematical Abilities?

Abstract

Spatial representations of number, such as a left-to-right oriented mental number line, are well documented in Western culture. Yet, the functional significance of such a representation remains unclear. To test the prominent hypothesis that a mental number line may support mathematical development, we examined the relation between spatial-numerical associations (SNAs) and math proficiency in 5- to 7-year-old children. We found evidence of SNAs with two tasks: a non-symbolic magnitude comparison task, and a symbolic “Where was the number?” (WTN) task. Further, we found a significant correlation between these two tasks, demonstrating convergent validity of the directional mental number line across numerical format. Although there were no significant correlations between children’s SNAs on the WTN task and math ability, children’s SNAs on the magnitude comparison task were negatively correlated with their performance on a measure of cross-modal arithmetic, suggesting that children with a stronger left-to-right oriented mental number line were less competent at cross-modal arithmetic, an effect that held when controlling for age and a set of general cognitive abilities. Despite some evidence for a negative relation between SNAs and math ability in adulthood, we argue that the effect here may reflect task demands specific to the magnitude comparison task, not necessarily an impediment of the mental number line to math performance. We conclude with a discussion of the different properties that characterize a mental number line and how these different properties may relate to mathematical ability.

Asymmetric number–space association leads to more efficient processing of congruent information in domestic chicks

“…Such an association in humans was previously attributed to formal instruction and culture (i.e., acquisition of reading and writing conventions). However, recent literature suggests that it is rather a shared and predisposed biological phenomenon, and this hypothesis is further supported by our study (Rugani and de Hevia, 2017;Aulet and Lourenco, 2018;McCrink et al, 2020;de Hevia, 2021;Rugani et al, 2022c). The valence hypothesis presented in the introduction could represent an example of hemispheric specializations at the basis of the SNA.…”

Spatial–numerical associations from a novel paradigm support the mental number line account

“…We also did not observe a significant vertical d-SNA in either Experiment 1 or 3, suggesting a privileged relation between numbers and horizontal space (see also Aulet & Lourenco, 2018, for a similar effect in children). In addition, this finding challenges a recent hypothesis that, in the absence of contextual priming (i.e., explicit magnitude or spatial-directional processing), vertical, but not horizontal, d-SNAs are observed (Shaki & Fischer, 2018;Sixtus et al, 2019).…”

Non-symbolic numerosities do not automatically activate spatial–numerical associations: Evidence from the SNARC effect

“…While there has been comparatively little research into SNARC effects for non-symbolic number in adults, there are a number of studies that report SNARC (or SNARC-like) effects in young children (e.g., Aulet & Lourenco, 2018; Bulf et al, 2016; De Hevia, Girelli, Addabbo, & Cassia, 2014; Ebersbach et al, 2014; Patro & Haman, 2012). In many of these studies, magnitude is relevant to the task (Aulet & Lourenco, 2018; Ebersbach et al, 2014; Patro & Haman, 2012), but some have used tasks that did not require magnitude processing. In a modified version of the cueing paradigm used by Bulf et al (2014) in adults, Bulf et al (2016) found that two-dot arrays oriented 8- to 9-month-olds’ visual attention to the left side of space and nine-dot arrays to the right.…”