ANS acuity, mathematical ability and inhibitory control: A longitudinal perspective from First to Second grades

Recent research has turned increasing attention to the cognitive underpinnings of early mathematical competence. The Approximate Number System (ANS) is a non-verbal primitive cognitive system that allows to represent and estimate numerical quantity in an imprecise and intuitive way. It is present at birth, is amodal and it supports basic numerical computations like adding, subtracting and comparing quantities without using counting or numerical symbols. ANS acuity is the degree of precision of the internal quantity representation and there are considerable individual differences in ANS precision. Recent findings demonstrating a relationship between ANS acuity and mathematical ability have suggested that the ANS plays a foundational role on later-learned math skills. However, not all studies have found links between the ANS and mathematical ability in children and the evidence for a relationship in adults is mixed. It is still unclear if the relationship between the ANS and mathematical ability found in some studies could be mediated by other general cognitive abilities. Indeed, recent research findings suggest that this relationship may be the result of inhibition skills, rather than the precision of nonsymbolic representations. The primary purpose of this 2-year longitudinal study was to investigate the relationship between the ANS and mathematical ability, analysing the data separately for congruent and incongruent dot comparison task trials. We measured ANS acuity, verbal intelligence and different aspects of numerical and mathematical competence in 110 children twice, in first and second grade (Time 1 and Time 2), a year apart. ANS acuity was assessed with a computerized non-symbolic numerical comparison task. At Time 1, correlational analyses indicated that ANS acuity was associated with mathematical ability. This association was significant for both congruent and incongruent trials of the dot comparison task. In particular, it was found that the subgroup of children with higher ANS performance showed better mathematical ability than the subgroup of children with lower ANS performance. Also at Time 2, correlational analyses suggested an association between ANS acuity and mathematical ability and this positive correlation was significant for both congruent and incongruent trials again. These results are in contrast with the hypothesis that the relationship between the ANS and mathematical ability may be an artefact of the inhibitory control demands of incongruent trials in the dot comparison task. This study thereby suggests a tight link between the ANS and mathematical ability.