Abstract

The existence of an association between numbers and space is widely supported by cumulative data from behavioral, neuropsychological and neuroanatomical studies in adult subjects (de Hevia, Vallar and Girelli, 2006; 2008), but little is known about its ontogenetic origin. Recent evidence suggests that spatial-numeric association develops long before children begin formal reading-writing instruction (Opfer, Thompson and Furlong, 2010). The present study explores, in preschoolers, the presence of early directional indexes in processing of magnitude information and the association between these indexes and a mature numerical representation by means of a numerical estimation task (Siegler and Opfer, 2003). Results indicate that only a limited number of children expects magnitude increase (i.e., symbolic and non-symbolic) to occur from left to right and that this preference does not correlate with age. However, regardless of the directionality preferred (i.e., from left to right vs. from right to left), children who presented a stable number-space mapping performed more accurately a numerical estimation task.