The relationship of working memory and inhibition with different number knowledge skills in preschool children.

The purpose of this study was to analyze the contribution of specific executive function (EF) components to different number knowledge skills. A sample of 143 children attending the last year of preschool educational services (Mage = 65.01 months, SD = 3.57) were tested on five number knowledge tasks from the Numerical Intelligence Battery and four EF tasks assessing working memory (WM) and inhibition. First, we examined the interrelationship between different number skills; the results suggested that the relationship between basic informal skills (set comparison and number sequence) and formal skills (seriation of Arabic numerals and number comparison) was mediated by the ability to link sets to numerals. Next, we explored the contribution of WM and inhibition to different number knowledge skills. The structural equation model showed that WM and inhibition were differentially related to specific number knowledge skills. Specifically, WM predicted most components of number knowledge, including the two basic informal skills and the number comparison, whereas inhibition contributed to the seriation of Arabic numerals. The ability to link sets to numerals was predicted only by number sequence, not by EF components.

Which tasks measure what? Reflections on executive function development and a commentary on Podjarny, Kamawar, and Andrews (2017).

This article provides a selective review of the literature on executive function development and related topics, focusing on the conceptual and terminological confusions that might hinder communication among researchers in the field. The distinctions between working memory and updating, and between shifting and flexibility, are discussed. Methodological problems, which have implications regarding whether a certain task can be considered a measure of a psychological construct, are also discussed. Research on preschoolers is examined with particular attention because it is a rapidly growing but controversial field that seems in particular need of greater conceptual clarity. As a specific touchstone case, we discuss whether the Multidimensional Card Selection Task (MCST) created by Podjarny, Kamawar, and Andrews (2017) should better be considered a measure of concurrent cognitive flexibility or working memory capacity. It is argued that connecting tasks to theoretical constructs is not warranted unless based on rigorous empirical testing of well-formulated models.

How preschool executive functioning predicts several aspects of math achievement in Grades 1 and 3: A longitudinal study.

This longitudinal study analyzes whether selected components of executive function (EF) measured during the preschool period predict several indices of math achievement in primary school. Six EF measures were assessed in a sample of 5-year-old children (N = 175). The math achievement of the same children was then tested in Grades 1 and 3 using both a composite math score and three single indices of written calculation, arithmetical facts, and problem solving. Using previous results obtained from the same sample of children, a confirmatory factor analysis examining the latent EF structure in kindergarten indicated that a two-factor model provided the best fit for the data. In this model, inhibition and working memory (WM)-flexibility were separate dimensions. A full structural equation model was then used to test the hypothesis that math achievement (the composite math score and single math scores) in Grades 1 and 3 could be explained by the two EF components comprising the kindergarten model. The results indicate that the WM-flexibility component measured during the preschool period substantially predicts mathematical achievement, especially in Grade 3. The math composite scores were predicted by the WM-flexibility factor at both grade levels. In Grade 3, both problem solving and arithmetical facts were predicted by the WM-flexibility component. The results empirically support interventions that target EF as an important component of early childhood mathematics education.

Inhibitory processes in toddlers: a latent-variable approach.

The aim of this study was to investigate the nature of inhibitory processes in early childhood. A confirmatory factor analysis was used to examine the latent structure of inhibitory processes in day-care center children aged 24-32 months and in preschool children aged 36-48 months. The best fit to the data for the younger sample was a single undifferentiated inhibition factor model; in older children, a two-factor model was differently identified in which response inhibition and interference suppression were distinguished.

Temperamental profiles and language development: a replication and an extension.

Individual differences in child temperament are associated with individual differences in language development. The present study examined the relationship between temperament and language ability in 109 twenty-four- to 30-month-old children. Parents and day-care teachers completed two questionnaires: the Primo Vocabolario del Bambino (Caselli & Casadio, 1995) and the Questionari Italiani del Temperamento (Axia, 2002). Researchers administered the First Language Test (Axia, 1993) to assess productive and receptive language in each child. Replicating previous research (Usai, Garello, & Viterbori, 2009), day-care teachers identified three temperamental profiles: most of the children fit into the first profile, typical of the Italian population; another profile was made up of easily distractible and not very persistent children, with a poor capacity to modulate motor activity; and the third profile of children were inhibited in new situations. A relationship was found between temperament assessed by day-care teachers and different levels of linguistic competence. In particular, the groups of "inattentive" and "inhibited" children showed poorer lexical and morphological abilities and a more immature vocabulary, characterised by the presence of more primitive components of the lexical repertory compared to the group of "typical" children. Unlike the results from day-care teachers, temperament questionnaires completed by parents revealed a 4-cluster-solution. Also, for parents, the "typical" profile is characterised by the largest vocabulary (productive and receptive) and the most mature semantic production.

Temperamental profiles and linguistic development: differences in the quality of linguistic production in relation to temperament in children of 28 months.

The temperamental constellations that can be found in the infant population may influence the development trajectories of single domains of knowledge, such as that relative to language. The main objective of this study is to identify temperamental profiles to which one associates different levels of linguistic competence and to identify the profile associated with the highest risk for language acquisition. The temperamental characteristics of a sample of 106 children of 28 months attending day-care centres were surveyed and three temperamental profiles were highlighted: a profile typical of the Italian population which grouped most of the children; another made up of easily distractible and not very persistent children, who show a poor capacity to modulate motor activity and finally, the third with children inhibited in new situations. A comparison of the three groups on the basis of the level of linguistic competence revealed important differences regarding certain indices such as the vocabulary size and composition: in particular, the group of "inattentive" children has a more "immature" vocabulary composition, characterised by the presence of more primitive components of the lexical repertory.