Two behavioral experiments assessed the plasticity and short-term improvement of task switching in 215 children and adults. Specifically, we studied manipulations of cued attention to different features of a target stimulus as a way to assess the development of cognitive flexibility. Each experiment had multiple levels of difficulty via manipulation of number of cued features (2–4) and number of response options (2 or 4). Working memory demand was manipulated across the two experiments. Impact of memory demand and task level manipulations on task accuracy and response times were measured. There were three overall goals: First, these task manipulations (number of cued features, response choices, and working memory load) were tested to assess the stability of group differences in performance between children ages 6–16 years and adults 18–27 years, with the goal of reducing age group differences. Second, age-related transitions to adult-level performance were examined within subgroups of the child sample. Third, short-term improvement from the beginning to the end of the study session was measured to probe whether children can improve with task experience. Attempts to use task manipulations to reduce age differences in cued task switching performance were unsuccessful: children performed consistently worse and were more susceptible to task manipulations than adults. However, across both studies, adult-like performance was observed around mid-adolescence, by ages 13-16 years. Certain task manipulations, especially increasing number of response options when working memory demand was low, produced differences from adults even in the oldest children. Interestingly, there was similar performance improvement with practice for both child and adult groups. The higher memory demand version of the task (Experiment 2) prompted greater short-term improvement in accuracy and response times than the lower memory demand version (Experiment 1). These results reveal stable differences in cued switching performance over development, but also relative flexibility within a given individual over time.

This work explores whether the facilitative effect of causal information on preschoolers’ word learning observed in the laboratory might be relevant to boosting children’s vocabulary in a group-play context. Forty-eight 3- to 4-year-old children learned six novel words for novel tools introduced during a small group-play session. Half of the groups used the tools according to their specified function to construct a fruit salad. The remaining children used the same tools to decorate a castle of blocks. In this way, some children learned about the causal properties of the tools, while others did not. Although children in both conditions comprehended the novel words equally well when tested shortly after the play session, learning in the Causal condition was more robust. Children’s comprehension scores in the Causal condition increased over time (a 7–20 day delay), such that children in this group performed better than children in the Non-Causal condition when tested in a follow-up session. These results demonstrate a striking benefit of causal enrichment to word learning in a context that could feasibly be implemented in preschool classrooms, playgroups, and individual households. Highlighting the causal properties of objects during playtime might offer a powerful approach to building children’s vocabulary, thereby providing a stronger foundation for early literacy and success in school more generally speaking.

Fostering early literacy depends in part on engaging and inspiring children's early interest in reading. Enriching the causal content of children's books may be one way to do so, as causal information has been empirically shown to capture children's attention. To more directly test whether children's book preferences might be driven by causal content, we created pairs of expository books closely matched for content and complexity, but with differing amounts of causal information embedded therein. Three and 4 years old participants (n = 48) were read both books and their interests and preferences were evaluated. When asked to choose, children preferred the highly causal over the minimally causal books. Results are discussed in terms of broader implications for creating books that optimally engage young children, as well as guiding book selections parents and educators make in their endeavors to promote interest in reading and early literacy.

Previous work suggests that children engage preparatory processing differently than adults in cued task switching. One potential consequence is that they are differentially biased by visual properties of the stimuli, for example, target-choice similarity. We tested this possibility in 215 children and young adults ranging from 6 to 27 years of age. Participants played a cue-target game with varying levels of working memory and attentional demand where they matched multidimensional stimuli according to a cued dimension. Younger age, low working memory demand, and matching fine grained dimensions (i.e., pattern) increased the bias of target-choice similarity on task performance. Older age, high working memory, and matching global dimensions (i.e., shape) mitigated the bias. Developmental transitions to adult performance differed by task demands but generally occurred during adolescence. A drift diffusion analysis revealed age and task differences in decision making strategies consistent with how similarity impacted task performance, indicating that, especially with low working memory demand, children made impulsive, similarity-driven decisions. Our findings support the idea that children engage in preparation strategies that exacerbate perceptual biases on task performance; improvements are observed with age or through changes in task structure and stimuli. These results have implications for interpreting cognitive control performance in children. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

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