The development of number line estimation in children at risk of mathematics learning difficulties: A longitudinal study.

Children with mathematics learning difficulties (MLD) show poorer performance on the number line task, but how performance on this task relates to other mathematical skills is unclear. This study examined the association between performance on the number line task and mathematical skills during the first 2 years of school for children at risk of MLD. Children (N = 100; Mage = 83.63 months) were assessed on four occasions on the number line task and other mathematical skills (math fluency, numerical operations, and mathematical reasoning). Estimation patterns were analyzed based on the representational shift and proportional judgment accounts separately. More consistent longitudinal trends and stronger evidence for differences in mathematical skills based on estimation patterns were found within the representational shift account. Latent growth curve models showed accuracy on the number line task as a predictor of growth in some mathematical skills assessed. We discuss impacts of methodological limitations on the study of estimation patterns.

Developmental dyscalculia is not associated with atypical brain activation: A univariate fMRI study of arithmetic, magnitude processing, and visuospatial working memory.

Functional neuroimaging serves as a tool to better understand the cerebral correlates of atypical behaviors, such as learning difficulties. While significant advances have been made in characterizing the neural correlates of reading difficulties (developmental dyslexia), comparatively little is known about the neurobiological correlates of mathematical learning difficulties, such as developmental dyscalculia (DD). Furthermore, the available neuroimaging studies of DD are characterized by small sample sizes and variable inclusion criteria, which make it problematic to compare across studies. In addition, studies to date have focused on identifying single deficits in neuronal processing among children with DD (e.g., mental arithmetic), rather than probing differences in brain function across different processing domains that are known to be affected in children with DD. Here, we seek to address the limitations of prior investigations. Specifically, we used functional magnetic resonance imaging (fMRI) to probe brain differences between children with and without persistent DD; 68 children (8-10 years old, 30 with DD) participated in an fMRI study designed to investigate group differences in the functional neuroanatomy associated with commonly reported behavioral deficits in children with DD: basic number processing, mental arithmetic and visuo-spatial working memory (VSWM). Behavioral data revealed that children with DD were less accurate than their typically achieving (TA) peers for the basic number processing and arithmetic tasks. No behavioral differences were found for the tasks measuring VSWM. A pre-registered, whole-brain, voxelwise univariate analysis of the fMRI data from the entire sample of children (DD and TA) revealed areas commonly associated with the three tasks (basic number processing, mental arithmetic, and VSWM). However, the examination of differences in brain activation between children with and without DD revealed no consistent group differences in brain activation. In view of these null results, we ran exploratory, Bayesian analyses on the data to quantify the amount of evidence for no group differences. This analysis provides supporting evidence for no group differences across all three tasks. We present the largest fMRI study comparing children with and without persistent DD to date. We found no group differences in brain activation using univariate, frequentist analyses. Moreover, Bayesian analyses revealed evidence for the null hypothesis of no group differences. These findings contradict previous literature and reveal the need to investigate the neural basis of DD using multivariate and network-based approaches to brain imaging.

Readability and beyond - Health literacy and numeracy and COVID-19 communications in early childhood education: Are we communicating effectively?

OBJECTIVE: Analyse the linguistic and numerical complexity of COVID-19-related health information communicated from Australian national and state governments and health agencies to national and local early childhood education (ECE) settings. METHODS: Publicly available health information (n = 630) was collected from Australian national and state governments and health agencies, and ECE agencies and service providers. A purposive sample of documents (n = 33) from 2020 to 2021 was analysed inductively and deductively combining readability, health numeracy and linguistic analyses and focusing on the most frequent actionable health advice topics. RESULTS: COVID-19 health advice most frequently related to hygiene, distancing and exclusion. Readability scores in 79% (n = 23) of documents were above the recommended grade 6 reading level for the public. Advice was delivered using direct linguistic strategies (n = 288), indirect strategies (n = 73), and frequent mitigating hedges (n = 142). Most numerical concepts were relatively simple, but lacked elaborative features (e.g., analogies) and/or required subjective interpretation. CONCLUSION: COVID-19 health advice available to the ECE sector included linguistic and numerical information open to mis/interpretation making it difficult to understand and implement. PRACTICE IMPLICATIONS: Combining readability scores with measures of linguistic and numerical complexity offers a more holistic approach to assessing accessibility of health advice and improving health literacy among its recipients.

Heterogeneity in children at risk of math learning difficulties.

This study recruited 428 Singaporean children at risk of math learning difficulties (MLD; Mage  = 83.9 months, SDage  = 4.35 months; 41% female). Using a factor mixture model that considered both quantitative and qualitative differences in math ability, two qualitatively different groups were identified: one with generalized difficulties across different math skills and the other with more focal difficulties in arithmetic fluency. Reading, working memory capacity, and numeracy (number line estimation skills and numerical discrimination) uniquely explained group membership. Children within each group differed in the extent of difficulties they exhibited, with numeracy variables differentially contributing to math ability in each group. Findings speak against a dimensional view of MLD and underscore the conceptual limitations of using basic numeracy performance to profile learning difficulties.

Screening for executive function difficulties: An evaluation of the Behavior Rating Inventory of Executive Function-2nd Edition Screener, Teacher Report (BRIEF2-TS).

Executive functions (EFs) correlate positively with many developmental outcomes, and ecologically valid measures of EFs may be more predictive of some outcomes than performance-based measures. Accordingly, there is a need to evaluate short EF rating scales, such as the Behavior Rating Inventory of Executive Function-2nd Edition Screener, Teacher Report (BRIEF2-TS). Data from 1,322 kindergarten children in Singapore (50% girls; 61.3% Chinese, 10.6% Malay, 16.3% Indian, 4.0% other ethnicity, and 7.8% did not report their ethnicity), followed for 3 years, were used to examine the multilevel factor structure, gender and longitudinal invariance, reliability, and concurrent and predictive validity of BRIEF2-TS scores. Results indicated a two-factor within-level structure (11 items; cognitive and emotional-behavioral regulation) that was at least partially invariant across gender and time. Concurrent validity with direct EF measures and ratings of self-regulation, and predictive validity for socioemotional and academic skills were good. Overall, BRIEF2-TS scores showed evidence for good validity and reliability. Future research should consider correlates of the between-level structure and further consider structure and validity in clinical samples. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Workplace Bullying in Early Childhood Education Settings: Prevalence and Protective Factors.

Workplace bullying in the early childhood education and care (ECEC) sector is a pervasive and significant issue in Australia and globally. Workplace bullying can negatively impact early childhood professionals' mental health, contributing to staff turnover and attrition. Given the current, and predicted, future shortages of ECEC staff, it is critical that strategies be implemented to support staff well-being and maintain healthy and safe workplaces. The aims of this study were to examine the current prevalence of workplace bullying in the ECEC sector in Australia and to identify protective workplace factors associated with lower prevalence of workplace bullying. Using a convergent parallel mixed methods design, findings are drawn from qualitative and quantitative survey questions within a large study on ECEC educators' well-being conducted in Australia. Participants were 591 early childhood professionals working in ECEC a variety of ECEC settings. Findings indicated that 24.6% of respondents reported experiencing workplace bullying and that most bullying was perpetrated by co-workers. Some workplace factors were related to lower rates of bullying, including positive teamwork, better supervisor relations, lower work-related stressors and having greater influence on workplace decisions. Implications of the findings are discussed in relation to informing policy and practices to address workplace bullying in the ECEC sector by identifying aspects of the workplace that serve as protective factors.

L'intimidation au travail dans le secteur de l'éducation et de la garde des jeunes enfants (EAJE) est un problème omniprésent et important en Australie et dans le monde. L'intimidation au travail peut avoir un impact négatif sur la santé mentale des professionnels de la petite enfance, contribuant au roulement et à l'attrition du personnel. Compte tenu des pénuries actuelles et prévues de personnel d'EAJE, il est essentiel que des stratégies soient mises en oeuvre pour soutenir le bien-être du personnel et maintenir des lieux de travail sains et sûrs. Les objectifs de cette étude étaient d'examiner la prévalence actuelle de l'intimidation au travail dans le secteur de l'EAJE en Australie et d'identifier les facteurs de protection sur le lieu de travail associés à une prévalence plus faible de l'intimidation au travail. En utilisant une conception de méthodes mixtes parallèles convergentes, les résultats sont tirés de questions d'enquête qualitatives et quantitatives dans le cadre d'une vaste étude sur le bienêtre des éducateurs de l'EAJE menée en Australie. Les participants étaient 591 professionnels de la petite enfance travaillant dans divers contextes d'EAJE. Les résultats ont indiqué que 24,6 % des répondants ont déclaré avoir été victimes d'intimidation au travail et que la plupart des intimidations étaient perpétrées par des collègues. Certains facteurs liés au lieu de travail étaient liés à des taux plus faibles d'intimidation, notamment un travail d'équipe positif, de meilleures relations avec les superviseurs, des facteurs de stress liés au travail moins élevés et une plus grande influence sur les décisions en milieu de travail. Les implications des résultats sont discutées par rapport à la politique et aux pratiques d'information pour lutter contre l'intimidation au travail dans le secteur de l'EAJE en identifiant les aspects du lieu de travail qui servent de facteurs de protection.

Non-symbolic Ratio Reasoning in Kindergarteners: Underlying Unidimensional Heuristics and Relations With Math Abilities.

Although it is thought that young children focus on the magnitude of the target dimension across ratio sets during binary comparison of ratios, it is unknown whether this is the default approach to ratio reasoning, or if such approach varies across representation formats (discrete entities and continuous amounts) that naturally afford different opportunities to process the dimensions in each ratio set. In the current study, 132 kindergarteners (Mage = 68 months, SD = 3.5, range = 62-75 months) performed binary comparisons of ratios with discrete and continuous representations. Results from a linear mixed model revealed that children followed an additive strategy to ratio reasoning-i.e., they focused on the magnitude of the target dimension across ratio sets as well as on the absolute magnitude of the ratio set. This approach did not vary substantially across representation formats. Results also showed an association between ratio reasoning and children's math problem-solving abilities; children with better math abilities performed better on ratio reasoning tasks and processed additional dimensions across ratio sets. Findings are discussed in terms of the processes that underlie ratio reasoning and add to the extant debate on whether true ratio reasoning is observed in young children.

Order processing of number symbols is influenced by direction, but not format.

This study probed the cognitive mechanisms that underlie order processing for number symbols, specifically the extent to which the direction and format in which number symbols are presented influence the processing of numerical order, as well as the extent to which the relationship between numerical order processing and mathematical achievement is specific to Arabic numerals or generalisable to other notational formats. Seventy adults who were bilingual in English and Chinese completed a Numerical Ordinality Task, using number sequences of various directional conditions (i.e., ascending, descending, mixed) and notational formats (i.e., Arabic numerals, English number words, and Chinese number words). Order processing was found to occur for ascending and descending number sequences (i.e., ordered but not non-ordered trials), with the overall pattern of data supporting the theoretical perspective that the strength and closeness of associations between items in the number sequence could underlie numerical order processing. However, order processing was found to be independent of the notational format in which the numerical stimuli were presented, suggesting that the psychological representations and processes associated with numerical order are abstract across different formats of number symbols. In addition, a relationship between the processing speed for numerical order judgements and mathematical achievement was observed for Arabic numerals and Chinese number words, and to a weaker extent, English number words. Together, our findings have started to uncover the cognitive mechanisms that could underlie order processing for different formats of number symbols, and raise new questions about the generalisability of these findings to other notational formats.

Maternal education and siblings: Agents of cognitive development in kindergarten.

In this study (n = 1000, Mage at K1entry  = 53.4 months, SD = 3.4; 53% females), we investigated the contributions of the family socioeconomic status (SES; maternal education and an income-related measure) and number and age of siblings to the development of children's math, reading, and working memory (WM) updating skills over the kindergarten years. Results from a multivariate multilevel growth curve model showed that children from more disadvantaged SES backgrounds already had a multifaceted developmental lag at kindergarten entry. Maternal education was the aspect of SES that more clearly affected the child's cognitive development; the mother's education predicted children's math, reading, and WM-updating skills at kindergarten entry as well as the rate of development of reading skills over the kindergarten years. Independently of SES status, children with more siblings also showed poorer reading and math skills than those in one-child families at kindergarten entry. We also found that both older and younger siblings affected, negatively, children's reading skills before they attended kindergarten-which suggests that the development of reading skills is more responsive to environmental factors during the first years than other aspects of the child development. The findings underscore the independent role of siblings upon entry to kindergarten, and the enduring role of maternal education even after children are exposed to formal schooling.

Validation of the Child Behavior Rating Scale (CBRS) using multilevel factor analysis.

Behavioral regulation supports children to control their cognitive and emotional skills and participate fully in classroom learning and interactions. Teacher ratings are frequently used to collect data but are highly susceptible to the teacher's response bias, meaning much child level variance is attributable to the teacher level. Multilevel modeling techniques are commonly used to assess the psychometric properties of measures at different levels by disaggregating within- and between-teacher variation in student behaviors. In this study, we attempt to identify the factor structure at each level using teacher ratings on the Child Behavior Rating Scale (CBRS). The sample of 1,375 preschool children (49.2% males) was drawn from a longitudinal study in Singapore. The teacher ratings of these children were collected at three time points (average age at Time 1 was 58.5 months, Time 2 was 69.8 months, and Time 3 was 80.9 months). Using multilevel exploratory and confirmatory factor analyses, a three-factor model at the within level and a two-factor model at the between level best fit the data. At the within level, the three factors were identified as basic interpersonal skills, advanced interpersonal skills, and learning-related social skills. The three factors showed good internal consistency and differential correlates. The two factors at the between level may be related to teacher and classroom characteristics. This study provides empirical support for (a) differential factor structures of CBRS at the within and between levels; and (b) two distinct interpersonal skills. Future studies should aim at exploring the sources of between level variability. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Cross- and Within-Domain Associations of Early Reading and Mathematical Skills: Changes Across the Preschool Years.

Existing research has mainly examined the role of cognitive correlates of early reading and mathematics from a stationary perspective that does not consider how these skills unfold and interact over time. This approach constraints the interpretation of cross-domain associations and the specificity of domain-specific covariates. In this study, we disentangle the role of these predictors and investigate cross-domain associations between reading, math, and two related domain-specific predictors (phonological awareness and fluency with number sets) over the kindergarten years (n=512, Mage=54months, SDage=3.5, 52% females). Results reveal that the overlap between reading and math skills changes over development. Reciprocal associations between reading and math abilities are observed at earlier stages; then, reading abilities become the lead force. Findings also show that phonological awareness and fluency with number sets are domain-specific predictors that do not contribute to cross-domain gains in academic skills. Indeed, there is a trend for domain-specific skills to be more strongly related to achievement at the beginning of formal education than at the beginning of kindergarten, which suggests an increasing differentiation of domains over the kindergarten years. Such findings have implications for the timing and nature of interventions that aim to support children's reading and mathematical development.

Socioeconomic status, home mathematics environment and math achievement in kindergarten: A mediation analysis.

Growing evidence suggests that parents' practices contribute to their children's cognitive development and that such practices may reflect SES disparities. This study investigated longitudinal interrelations between home mathematics environment (HME), children's math achievement, and two facets of SES (mother's educational attainment and household income-subsidy status) during the first year in kindergarten (n = 500 children; Mage at T1 = 57.3 months, SD = 3.8). Results revealed that these facets of SES operated through different mechanisms in kindergarten-the association between mothers' education and math growth at the end of K1 is fully mediated by HME and children's baseline math knowledge. Furthermore, only home math activities that explicitly supported the understanding of addition and subtraction contributed to children's math growth independently of SES background. The pattern of longitudinal associations suggests that the provision of home math activities may reflect children's mathematical abilities rather than SES disparities.

Non-symbolic numerosities do not automatically activate spatial-numerical associations: Evidence from the SNARC effect.

The SNARC (spatial-numerical association of response codes) effect is the finding that people are generally faster to respond to smaller numbers with left-sided responses and larger numbers with right-sided responses. The SNARC effect has been widely reported for responses to symbolic representations of number such as digits. However, there is mixed evidence as to whether it occurs for non-symbolic representations of number, particularly when magnitude is irrelevant to the task. Mitchell et al. reported a SNARC effect when participants were asked to make orientation decisions to arrays of one-to-nine triangles (pointing upwards vs. pointing downwards) and concluded that SNARC effects occur for non-symbolic, non-canonical representations of number. They additionally reported that this effect was stronger in the subitising range. However, here we report four experiments that do not replicate either of these findings. Participants made upwards/inverted decisions to one-to-nine triangles where total surface area was either controlled across numerosities (Experiments 1, 2, and 4) or increased congruently with numerosity (Experiment 3). There was no evidence of a SNARC effect either across the full range or within the subset of the subitising range. The results of Experiment 4 (in which we presented the original stimuli of Mitchell et al.) suggested that visual properties of non-symbolic displays can prompt SNARC-like effects driven by visual cues rather than numerosity. Taken in the context of other recent findings, we argue that non-symbolic representations of number do not offer a direct and automatic route to numerical-spatial associations.

Automaticity of access to numerical magnitude and its spatial associations: The role of task and number representation.

Generally, people respond faster to small numbers with left-sided responses and large numbers with right-sided responses, a pattern known as the SNARC (spatial numerical association of response codes) effect. The SNARC effect is interpreted as evidence for amodal automatic access of magnitude and its spatial associations, because it occurs in settings where number is task-irrelevant and for different number formats. We report five studies designed to establish the degree to which activation of magnitude and its spatial associations is truly automatic and amodal. Based on the notion of autonomous automaticity, we hypothesized that the mere presence of a number form (to which participants made a color decision) would be sufficient to elicit the SNARC effect. However, we found no evidence of a SNARC effect for simple color decisions to Arabic digits (Experiment 1). There was a SNARC effect for color decision to digits when participants recognized the stimulus as a digit before responding (Experiment 2), participants viewed the digit for sufficient time before color onset (Experiments 3 and 5), or there was temporal uncertainty regarding color onset (Experiment 3). There was no SNARC effect for color decision to arrays of circles (Experiment 4), regardless of viewing time or temporal uncertainty. Overall, our results suggest that, while access to magnitude and its spatial associations is not automatic in an "all-or-none" sense, it is certainly at the strong end of automaticity, and that this automatic activation is modality dependent. Our findings are most supportive of conceptual coding accounts of the SNARC effect. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Magnitude processing of written number words is influenced by task, rather than notation.

The extent to which task and notation influence the processing of numerical magnitude is under theoretical and empirical debate. To date, behavioural studies have yielded a mixed body of evidence. Using the case of written number words in English and Chinese, we re-examined this issue. Thirty-nine bilingual participants who showed a balanced profile of language dominance in English and Chinese completed three tasks of numerical processing (Magnitude Comparison, Numerical Matching, and Language Matching) with pure English, pure Chinese, and mixed notation number words. We conducted frequentist and Bayesian statistics on the data. Magnitude processing, as indexed by the numerical distance effect (NDE), was found to be dependent on task. Specifically, the NDE occurred in all notation conditions in the Magnitude Comparison Task and mixed notation trials in the Numerical Matching Task only. However, the data indicated that magnitude processing was independent of notation. Task and notation had an interactive influence on overall speed of processing, where participants responded to Chinese number words significantly faster than other notations for the Magnitude Comparison and Numerical Matching Tasks only. Finally, Bayesian analyses indicated that task and notation do not interact to affect magnitude processing. Specifically, the Bayes Factor and posterior model probabilities of the Bayesian ANOVA yielded strongest support for the model with three main effects (Task, Notation, Numerical Distance) and two two-way interactions (Task × Numerical Distance, Task × Notation). These findings highlight the critical role of task in numerical magnitude processing, provide support for a notation-independent account of magnitude processing, and suggest that linguistic/orthographic factors, combined with task, may interact to affect overall speed of processing.

Learning and solving algebra word problems: The roles of relational skills, arithmetic, and executive functioning.

Although algebra is a prerequisite for higher mathematics, few studies have examined the mathematical and cognitive capabilities that contribute to the development of algebra word problems solving skills. We examined changes in these relations from second to ninth grades. Using a cross-sequential design that spanned 4 years, children from 3 cohorts (Mage = 7.85, 10.05, and 12.32) were administered annual tests of algebra word problems, mathematical skills (mathematical relational tasks, arithmetic word problems), and cognitive capabilities (working memory, updating, inhibitory, task switching, and performance intelligence). The cross-sectional findings showed that ability to solve mathematical relational problems was associated strongly with performance in algebra word problems. Working memory and updating explained variance in the relational, but not the algebra problems. Using an autoregressive cross-lagged model with structured residuals to analyze the longitudinal data, we found relational and arithmetic performance predicted independently algebra performance from one year to the next. The strength of these relations was consistent across grades. These findings point to the importance of developing skills in relational problems as one of the tools for improving algebra performance. (PsycINFO Database Record

The approximate number system and domain-general abilities as predictors of math ability in children with normal hearing and hearing loss.

Many children with hearing loss (CHL) show a delay in mathematical achievement compared to children with normal hearing (CNH). This study examined whether there are differences in acuity of the approximate number system (ANS) between CHL and CNH, and whether ANS acuity is related to math achievement. Working memory (WM), short-term memory (STM), and inhibition were considered as mediators of any relationship between ANS acuity and math achievement. Seventy-five CHL were compared with 75 age- and gender-matched CNH. ANS acuity, mathematical reasoning, WM, and STM of CHL were significantly poorer compared to CNH. Group differences in math ability were no longer significant when ANS acuity, WM, or STM was controlled. For CNH, WM and STM fully mediated the relationship of ANS acuity to math ability; for CHL, WM and STM only partially mediated this relationship. ANS acuity, WM, and STM are significant contributors to hearing status differences in math achievement, and to individual differences within the group of CHL. Statement of contribution What is already known on this subject? Children with hearing loss often perform poorly on measures of math achievement, although there have been few studies focusing on basic numerical cognition in these children. In typically developing children, the approximate number system predicts math skills concurrently and longitudinally, although there have been some contradictory findings. Recent studies suggest that domain-general skills, such as inhibition, may account for the relationship found between the approximate number system and math achievement. What does this study adds? This is the first robust examination of the approximate number system in children with hearing loss, and the findings suggest poorer acuity of the approximate number system in these children compared to hearing children. The study addresses recent issues regarding the contradictory findings of the relationship of the approximate number system to math ability by examining how this relationship varies across children with normal hearing and hearing loss, and by examining whether this relationship is mediated by domain-general skills (working memory, short-term memory, and inhibition).

Psychometric properties of the NEPSY-II affect recognition subtest in a preschool sample: a Rasch modeling approach.

OBJECTIVE: Understanding a child's ability to decode emotion expressions is important to allow early interventions for potential difficulties in social and emotional functioning. This study applied the Rasch model to investigate the psychometric properties of the NEPSY-II Affect Recognition subtest, a U.S. normed measure for 3-16 year olds which assesses the ability to recognize facial expressions of emotion. METHOD: Data were collected from 1222 children attending preschools in Singapore. We first performed the Rasch analysis with the raw item data, and examined the technical qualities and difficulty pattern of the studied items. We subsequently investigated the relation of the estimated affect recognition ability from the Rasch analysis to a teacher-reported measure of a child's behaviors, emotions, and relationships. Potential gender differences were also examined. RESULTS: The Rasch model fits our data well. Also, the NEPSY-II Affect Recognition subtest was found to have reasonable technical qualities, expected item difficulty pattern, and desired association with the external measure of children's behaviors, emotions, and relationships for both boys and girls. CONCLUSIONS: Overall, findings from this study suggest that the NEPSY-II Affect Recognition subtest is a promising measure of young children's affect recognition ability. Suggestions for future test improvement and research were discussed.

Older adults have difficulty in decoding sarcasm.

Younger and older adults differ in performance on a range of social-cognitive skills, with older adults having difficulties in decoding nonverbal cues to emotion and intentions. Such skills are likely to be important when deciding whether someone is being sarcastic. In the current study we investigated in a life span sample whether there are age-related differences in the interpretation of sarcastic statements. Using both video and verbal materials, 116 participants aged between 18 and 86 completed judgments about whether statements should be interpreted literally or sarcastically. For the verbal stories task, older adults were poorer at understanding sarcastic intent compared with younger and middle-aged participants, but there was no age difference in interpreting control stories. For the video task, older adults showed poorer understanding of sarcastic exchanges compared with younger and middle-aged counterparts, but there was no age difference in understanding the meaning of sincere interactions. For the videos task, the age differences were mediated by the ability to perceive facial expressions of emotion. Age effects could not be explained in terms of variance in working memory. These results indicate that increased age is associated with specific difficulties in using nonverbal and contextual cues to understand sarcastic intent. (PsycINFO Database Record

The role of numerical and non-numerical cues in nonsymbolic number processing: Evidence from the line bisection task.

In line bisection tasks, adults and children bisect towards the numerically larger of two nonsymbolic numerosities [de Hevia, M. D., & Spelke, E. S. ( 2009 ). Spontaneous mapping of number and space in adults and young children. Cognition, 110, 198-207. doi:10.1016/j.cognition.2008.11.003]. However, it is not clear whether this effect is driven by number itself or rather by visual cues such as subtended area [Gebuis, T., & Gevers, W. ( 2011 ). Numbers and space: Indeed a cognitive illusion! A reply to de Hevia and Spelke ( 2009 ). Cognition, 121, 248-252. doi:10.1016/j.cognition.2010.09.008]. Furthermore, this effect has only been demonstrated with flanking displays of two and nine items. Here, we report three studies that examined whether this "spatial bias" effect occurs across a range of absolute and ratio numerosity differences; in particular, we examined whether the bias would occur when both flankers were outside the subitizing range. Additionally, we manipulated the subtended area of the stimulus and the aggregate surface area to assess the influence of visual cues. We found that the spatial bias effect occurred for a range of flanking numerosities and for ratios of 3:5 and 5:6 when subtended area was not controlled (Experiment 1). However, when subtended area and aggregate surface area were held constant, the biasing effect was reversed such that participants bisected towards the flanker with fewer items (Experiment 2). Moreover, when flankers were identical, participants bisected towards the flanker with larger subtended area or larger aggregate surface area (Experiments 2 and 3). On the basis of these studies, we conclude that the spatial bias effect for nonsymbolic numerosities is primarily driven by visual cues.