Developmental traces of cognitive control on the processing of symbolic magnitude

The current study aimed to evaluate the developmental course of the interplay between the componential analysis of two-digit numbers, the conflict associated with magnitude processing, and the possible inhibitory mechanism used to resolve interference. To this end, children aged 7-11 years-old performed a magnitude comparison task involving two-digit numbers in sequences of two trials. The first trial involved compatible comparisons where the decade and the unit of one number were larger than those of the other number (i.e., 21-73), or incompatible comparisons where the decade of one number was larger but the unit was smaller than those of the other number (i.e., 61-53). The second trial involved related number pairs that contained the previously presented units (i.e., 41-43) or unrelated number pairs with units that had not appeared before (i.e., 48-49). Performance in the first trial was worse in incompatible trials than in compatible trials, and this compatibility effect increased with age. In the second trial, performance in related trials after incompatible trials was worse than in unrelated trials and this relation effect was found in all age groups. These results suggest that the development of numerical knowledge fosters the componential-parallel processing of multidigit numbers and that children need time to overcome inhibition after conflict resolution.