March 2013 - February 2014
Budget resources of KMR
Spatial-numerical associations (SNA, e.g. faster reactions to smaller numbers on the left side, and to larger numbers on the right side) were originally tested mostly in adult participants or school aged children in the context of processing Arabic numbers. Traditionally, it was believed that such associations are created in the course of school education and their orientation develops when children learn to read from left to right.
However, recent studies challenged this claim and showed that some forms of spatial-numerical links develop already before formal schooling. Since such developmental studies are not numerous, many questions about the nature and origins of early associations are still open. In our project, we try to determine basic properties of an early SNA based on two kinds of numerical processing: estimation of approximate numerosities (numerosity pairs are compared faster when smaller sets are presented on the left, and larger on the right side) and verbal counting (counting objects from left to right).
In the first study, we examine whether these two measures of SNA are related to each other. One may argue that each of them is based on a different kind of number representation (e.g., ordinal representations of verbal numerals vs. approximate representation of non-verbal cardinal numerosities). Therefore, they might reflect different kinds of number-space links.
In the second study, we explore dependencies of left-to-right biases for verbal counting on body-related spatial frames of reference. In particular, in children who have not yet developed stable expectations about left-to-right number ordering, direction of counting can be modulated by some non-numerical situational factors. One factor could be a hand used while counting (it is easier to count with the right hand from right to left than from left to right). Our preliminary data show the first evidence for such a counting-by-hand modulation. Another factor which is of main interest to us is a stimuli presentation modus. We hypothesize that verbal counting can be biased differently when stimuli are presented in a peripersonal space and children are engaged in a traditional counting task (counting with a finger), as compared to a condition when stimuli are projected to a distant space, and children have to count them with a laser pointer or with a whole body movement.
