Mixed-effects models are an analytic technique for modeling repeated measurement or nested data. This paper explains the logic of mixed-effects modeling and describes two examples of mixed-effects analyses using R. The intended audience of the paper is psychologists who specialize in cognitive development research. Therefore, the concepts and…

Cognitive control (also referred to as executive functions) corresponds to a set of cognitive processes that support the goal-directed regulation of thoughts and actions. It plays a major role in complex activities and predicts later academic achievement. Importantly, while growing up, children are progressively transitioning from engaging…

Executive function (EF) skills are a set of attention-regulation skills involved in intentional, goal-directed behavior that include (but are not limited to) the cool EF skills of working memory, cognitive flexibility, and inhibitory control, and also the hot EF skill of intentional reevaluation. These skills are inevitably expressed in goal- and…

Eye tracking is widely used in developmental research to measure infants' looking behavior before, during, or after particular events and can provide a measure of real-time processing. However, the dynamic time course of infants' looking behaviors is rarely analyzed. Instead, eye tracking data is often averaged within a large window or is…

In mathematically literate societies, numerical information is represented in 3 distinct codes: a verbal code (i.e., number words); a digital, symbolic code (e.g., Arabic numerals); and an analogical code (i.e., quantities; Dehaene, 1992). To communicate effectively using these numerical codes, our understanding of number must involve an…

In order for children to understand and reason about the world in an adult-like fashion, they need to learn that conceptual categories are organized in a hierarchical fashion (e.g., a dog is also an animal). While children learn from their first-hand observation of the world, social knowledge transmission via language can also play an important…

Numerical comparison is a primary measure of the acuity of children's approximate number system. Approximate number system acuity is associated with key developmental outcomes such as symbolic number skill, standardized test scores, and even employment outcomes (Halberda, Mazzocco, & Feigenson, 2008; Parsons & Bynner, 1997). We examined…

In our current culture, children are exposed to a huge amount of audiovisual media, of which many formats include animated pictures, such as in videos, for instance. The current study addresses the use of audiovisual media in order to increase the effectiveness of learning and teaching. We examined how auditory text, audiovisual text with static…

Two experiments examined whether concrete models support place value learning. In Experiment 1 (N = 149), 7-year-olds were trained with either a) symbols alone or b) symbols and base-10 blocks. Children in both groups showed significant growth overall, but there were specific effects favoring one training type over another. Symbols-only training…

This study examined the play of 4-year-old children with a forest diorama that included toy representations of plants and animals. To examine the potential role of culture and expertise in diorama play, children from 3 samples participated: rural Native American, urban Native American, and urban non-Native American. Children's playtime was divided…

The broader autism phenotype (BAP) is a term applied to individuals with personality and cognitive traits that are similar to but milder than those observed in autism spectrum disorder (ASD). Subtle autistic traits in the core diagnostic domains of social communication and rigid behavior were described in family members of people with an ASD even…

We describe research results and lessons learned from a laboratory/classroom collaboration with a school system offering both traditional English-only education and a dual-language track (Spanish/English). Through this collaboration, we addressed basic research questions informing malleable factors that impact cognitive development. In a…

During the first 5 years of life, the versatility, breadth, and fidelity with which children imitate change dramatically. Currently, there is no model to explain what underlies such significant changes. To that end, the present study examined whether task-independent but domain-specific--elemental--imitation mechanism explains performance across…

The current study tested 2 models of inhibition in 45 children with language impairment and 45 children with normally developing language; children were aged 7 to 12 years. Of interest was whether a model of inhibition as a mental-control process (i.e., executive function) or as a mental resource would more accurately reflect the relations among…

Rakison and Yermolayeva (this issue) argue that domain specificity is difficult to reconcile with U-, N-, or M-shaped developmental trends. They are justified because: (1) There is no compelling evidence that nonlinear trends require mechanisms beyond general, well-known cognitive processes; and (2) epigenetic neuroscience provides no clear…