The processing of symbolic and non-symbolic numerical ratios

Meert, Gaëlle [UCL] Grégoire, Jacques [UCL] Noël, Marie-Pascale [UCL]

This study investigated the processing of numerical ratios. More particularly, we studied the impact of the symbolic notation on that processing in school-age children and adults. Nine- and eleven-year-olds, as well as adults, were asked to estimate the magnitude of fractions (symbolic stimuli) and the numerical ratio between dot collections (non-symbolic stimuli). For the non-symbolic stimuli, the ratio of surface areas did or did not co-vary with the numerical ratio (respectively, homogeneous-dot and heterogeneous-dot conditions). The results showed that, compared to the heterogeneous-dot condition, performance on fractions was similar in 9-year-olds, and better in 11-year-olds and in adults. Furthermore, performance was better in the homogeneous-dot than in the heterogeneous-dot condition, indicating that the participants relied, at least in part, on the ratio of surface areas in the former condition. These results suggest that, in children as young as 11-year old, the mental representation of the ratio magnitude is more accurate when it is activated from symbolic stimuli, and that the processing of non-symbolic numerical ratios is costly enough in terms of time and/or resources to be affected by non-numerical ratios. The theoretical and methodological implications of these results will be discussed.