Working memory training improves children's cognitive performance on untrained tasks; however, little is known about the underlying neural mechanisms. This was investigated in 32 typically developing children aged 10-14 years (19 girls and 13 boys) using a randomized controlled design and multi-modal magnetic resonance imaging (Devon, UK;…

The Wechsler Preschool and Primary Scale of Intelligence, 4th ed. includes two measures of working memory normed on children 2;6-7;7. The present analyses of the typically developing children (N = 1,591, 812 female, 779 male, with an ethnic distribution approximating the United States) provide new, theoretically important information about these…

An inherent component of tool-use actions is the transformation of the user's operating movement into the desired effect. In this study, the relevance of this transformation for young children's learning of tool-use actions was investigated. Sixty-four children at the age of 27-30 months learned to use levers which either simply extended…

Jigsaw puzzles are ubiquitous developmental toys in Western societies, used here to examine the development of metarepresentation. For jigsaw puzzles this entails understanding that individual pieces, when assembled, produce a picture. In Experiment 1, 3- to 5-year-olds (N = 117) completed jigsaw puzzles that were normal, had no picture, or…

Memory decision-making in 26- to 32-month-olds was investigated using visual-paired comparison paradigms, requiring toddlers to select familiar stimuli (Active condition) or view familiar and novel stimuli (Passive condition). In Experiment 1 (N = 108, 54.6% female, 62% White; replication N = 98), toddlers with higher accuracy in the Active…

Is early reasoning about an agent's knowledge best characterized by a mentalistic stance, a teleological stance, or both? In this research, 5-month-old infants (N = 64, 50% female, 83% White) saw a novel eyeless agent consistently approach object-A as opposed to object-B. Although infants could always see both objects, a screen separated object-B…

This study investigated the development of rapid visual object categorization. N = 20 adults (Experiment 1), N = 21 five to six-year-old children (Experiment 2), and N = 140 four-, seven-, and eleven-month-old infants (Experiment 3; all predominantly White, 81 females, data collected in 2013-2020) participated in a fast periodic visual stimulation…

Executive function (EF) plays a foundational role in development. A brain-based model of EF development is probed for the experiences that strengthen EF in the dimensional change card sort task in which children sort cards by one rule and then are asked to switch to another. Three-year-olds perseverate on the first rule, failing the task, whereas…

Place value concepts were measured longitudinally from kindergarten (2017) to first grade (2018) in a diverse sample (n = 279; M[subscript age] = 5.76 years, SD = 0.55; 135 females; 41% Black, 38% White, 8% Asian, 12% Latino). Children completed three syntactic tasks that required an explicit understanding of base-10 symbols and three approximate…

This study examined whether executive functions impact how flexibly children represent task context in performing repeated sequential actions. Japanese children in Experiments 1 (N = 52; 3-6 years) and 2 (N = 50, 4-6 years) performed sequential actions repeatedly; one group received reminders. Experiment 1 indicated that reminders promote flexible…

Efficient attention control is fundamental for infant cognitive development, but its early precursors are not well understood. This study investigated whether dyadic visual attention during parent-infant interactions at 5 months of age predicts the ability to control attention at 11 months of age (N = 55). Total duration of mutual gaze (MG) was…

This study explored whether a daytime nap aids children's acquisition of letter-sound knowledge, which is a fundamental component for learning to read. Thirty-two preschool children in Sydney, Australia (M[subscript age] = 4 years;3 months) were taught letter-sound mappings in two sessions: one followed by a nap and the other by a wakeful period.…

Research has found mixed evidence for the production effect in childhood. Some studies have found a positive effect of production on word recognition and recall, while others have found the reverse. This paper takes a developmental approach to investigate the production effect. Children aged 2-6 years (n = 150) from a predominantly white…

This study examined future-oriented behavior in children (3-6 years; N = 193) from three diverse societies--one industrialized Western city and two small, geographically isolated communities. Children had the opportunity to prepare for two alternative versions of an immediate future event over six trials. Some 3-year-olds from all cultures…

In two experiments, one hundred and sixty-two 6- to 8-year-olds were asked to reason counterfactually about events with different causal structures. All events involved overdetermined outcomes in which two different causal events led to the same outcome. In Experiment 1, children heard stories with either an ambiguous causal relation between…