Katarzyna Patro

The spatial–numerical congruity effect in preschoolers

Number-to-space mapping and its directionality are compelling topics in the study of numerical cognition. Usually, literacy and math education are thought to shape a left-to-right number line. We challenged this claim by analyzing performance of preliterate precounting preschoolers in a spatial-numerical task. In our experiment, children exhibited a spatial-numerical congruity (SNC) effect during a nonsymbolic numerosity comparison (quicker reaction times to smaller sets presented on the left side of the screen and to larger ones presented on the right side). These findings suggest that left-to-right number ordering may also have some sources that are independent of reading and math education. We argue that the current explanations of the spatial-numerical link need to be reconsidered.

How number-space relationships are assessed before formal schooling: A taxonomy proposal

The last years of research on numerical development have provided evidence that spatial-numerical associations (SNA) can be formed independent of formal school training. However, most of these studies used various experimental paradigms that referred to slightly different aspects of number and space processing. This poses a question of whether all SNAs described in the developmental literature can be interpreted as a unitary construct, or whether they are rather examples of different, but related phenomena. Our review aims to provide a starting point for a systematic classification of SNA measures used from infancy to late preschool years, and their underlying representations. We propose to distinguish among four basic SNA categories: (i) cross-dimensional magnitude processing, (ii) associations between spatial and numerical intervals, (iii) associations between cardinalities and spatial directions, (iv) associations between ordinalities and spatial directions. Such systematization allows for identifying similarities and differences between processes and representations that underlie the described measures, and also for assessing the adequacy of using different SNA tasks at different developmental stages.

How space-number associations may be created in preliterate children: six distinct mechanisms

The directionality of space-number association (SNA) is shaped by cultural experiences. It usually follows the culturally dominant reading direction. Smaller numbers are generally associated with the starting side for reading (left side in Western cultures), while larger numbers are associated with the right endpoint side. However, SNAs consistent with cultural reading directions are present before children can actually read and write. Therefore, these SNAs cannot only be shaped by the direction of children’s own reading/writing behavior. We propose six distinct processes – one biological and five cultural/educational – underlying directional SNAs before formal reading acquisition: (i) Brain lateralization, (ii) Monitoring adult reading behavior, (iii) Pretend reading and writing, and rudimentary reading and writing skills, (iv) Dominant attentional directional preferences in a society, not directly related to reading direction, (v) Direct spatial-numerical learning, (vi) Other spatial-directional processes independent of reading direction. In this mini-review, we will differentiate between these processes, elaborate when in development they might emerge, discuss how they may create the SNAs observed in preliterate children and propose how they can be studied in the future.

SNARC for numerosities is modulated by comparative instruction (and resembles some non-numerical effects).

The spatial–numerical association of response codes (SNARC) effect is observed for both numerical (Arabic digits) and non-numerical stimuli (size, duration, height). However, in a context of comparative judgment, Arabic numbers are mapped onto space differently from sizes and heights: SNARC for Arabic digits is formed consistently in a certain cultural reading direction, whereas SNARC for sizes and heights is additionally modulated by comparative instruction (it reverses when participants choose larger magnitudes). In the present study, we test whether the spatial characteristic of magnitude processing revealed in a context of comparison is determined by a presence or lack of numerical content of the processed information, or it depends on specific directional experience (e.g., left-to-right ordering) associated with the processed magnitude format. We examine the SNARC effect with the pairwise comparison design, by using non-symbolic numerical stimuli (objects’ collections), for which the left-to-right spatial structure is not as exceedingly overlearned as for Arabic numbers. We asked participants from two reading cultures (left-to-right vs. mixed reading culture) to compare numerosities of two sets, choosing either a larger or smaller one. SNARC emerged in both groups. Additionally, it was modulated by comparative instruction: It appeared in a left-to-right direction when participants selected a smaller set, but it tended to reverse when participants selected a larger set. We conclude that spatial processing of numerosities is dissociated from spatial processing of Arabic numbers, at least in a context of comparative judgment. This dissociation could reflect differences in spatial ordering experience specific to a certain numerical input.

Playing Reading, Using Hands: Which Activities are Linked to Number-Space Processing in Preschool Children?

Abstract Literate subjects from Western cultures form spatial-numerical associations (SNA) in left-to-right direction, which follows their reading habits. In preliterate children, sources of SNA directionality are more disputable. One possibility is that SNA follows childrens early knowledge about text orientation. It could also reflect ipsilateral/contralateral tendencies in manual task execution. Furthermore, SNAs characteristics could differ depending on the evaluation method used. In this study, we test SNA in preliterate preschoolers using object counting, finger counting, and numerosity arrangement tasks. We examined the relations of SNA to childrens directional reading knowledge and their manual response tendencies. Left-to-right SNA was pronounced for object counting, disappeared for the numerosity task, and was reversed for finger counting. In all tasks, left-to-right SNA dominated in children who responded contralaterally with their hand. Reading knowledge was partially related to numerosity-based SNA, but not to other SNAs. Based on these findings, we discuss developmental characteristics of different forms of number-space associations.

Visuospatial biases in preschool children: Evidence from line bisection in three-dimensional space

Spatial attention in adults is characterized by systematic asymmetries across all three spatial dimensions. These asymmetries are evident when participants bisect horizontal, vertical, or radial lines and misplace their midpoints to the left, the top, or far from the body, respectively. However, bisection errors are rarely examined during early childhood. In this study, we examined the development of spatial-attentional asymmetries in three-dimensional (3D) space by asking preschool children (aged 3-6 years) to bisect horizontal, vertical, and radial lines. Children erred to the left with horizontal lines and to the top with vertical lines, consistent with the pattern reported in adults. These biases got stronger with age and were absent in the youngest preschoolers. However, by controlling for a possible failure in hitting the line, we observed an additional unpredicted pattern: Childrens pointing systematically deviated away from the line to an empty space on its left side (for vertical and radial lines) or above it (for horizontal lines). Notably, this task-irrelevant deviation was pronounced in children as young as 3 or 4 years. We conclude that asymmetries in spatial-attentional functions should be measured not only in task-relevant dimensions but also in task-irrelevant dimensions because the latter may reveal biases in very young children not typically observed in task-relevant measures.