Enhancing the executive functions of 3-year-olds in the Dimensional Change Card Sort task

Dynamic Field Theory of Executive Function: Identifying Early Neurocognitive Markers

In this Monograph, we explored neurocognitive predictors of executive function (EF) development in a cohort of children followed longitudinally from 30 to 54 months of age. We tested predictions of a dynamic field model that explains development in a benchmark measure of EF development, the dimensional change card sort (DCCS) task. This is a rule-use task that measures children's ability to switch between sorting cards by shape or color rules. A key developmental mechanism in the model is that dimensional label learning drives EF development. Data collection began in February 2019 and was completed in April 2022 on the Knoxville campus of the University of Tennessee. Our cohort included 20 children (13 female) all of whom were White (not Hispanic/Latinx) from an urban area in southern United States, and the sample annual family income distribution ranged from low to high (most families falling between $40,000 and 59,000 per year (note that we address issues of generalizability and the small sample size throughout the monograph)). We tested the influence of dimensional label learning on DCCS performance by longitudinally assessing neurocognitive function across multiple domains at 30 and 54 months of age. We measured dimensional label learning with comprehension and production tasks for shape and color labels. Simple EF was measured with the Simon task which required children to respond to images of a cat or dog with a lateralized (left/right) button press. Response conflict was manipulated in this task based on the spatial location of the stimulus which could be neutral (central), congruent, or incongruent with the spatial lateralization of the response. Dimensional understanding was measured with an object matching task requiring children to generalize similarity between objects that matched within the dimensions of color or shape. We first identified neural measures associated with performance and development on each of these tasks. We then examined which of these measures predicted performance on the DCCS task at 54 months. We measured neural activity with functional near-infrared spectroscopy across bilateral frontal, temporal, and parietal cortices. Our results identified an array of neurocognitive mechanisms associated with development within each domain we assessed. Importantly, our results suggest that dimensional label learning impacts the development of EF. Neural activation in left frontal cortex during dimensional label production at 30 months of age predicted EF performance at 54 months of age. We discussed these results in the context of efforts to train EF with broad transfer. We also discussed a new autonomy-centered EF framework. The dynamic field model on which we have motivated the current research makes decisions autonomously and various factors can influence the types of decisions that the model makes. In this way, EF is a property of neurocognitive dynamics, which can be influenced by individual factors and contextual effects. We also discuss how this conceptual framework can generalize beyond the specific example of dimensional label learning and DCCS performance to other aspects of EF and how this framework can help to understand how EF unfolds in unique individual, cultural, and contextual factors. Measures of EF during early childhood are associated with a wide range of development outcomes, including academic skills and quality of life. The hope is that broad aspects of development can be improved by implementing interventions aimed at facilitating EF development. However, this promise has been largely unrealized. Previous work on EF development has been limited by a focus on EF components, such as inhibition, working memory, and switching. Similarly, intervention research has focused on practicing EF tasks that target these specific components of EF. While performance typically improves on the practiced task, improvement rarely generalizes to other EF tasks or other developmental outcomes. The current work is unique because we looked beyond EF itself to identify the lower-level learning processes that predict EF development. Indeed, the results of this study identify the first learning mechanism involved in the development of EF. Although the work here provides new targets for interventions in future work, there are also important limitations. First, our sample is not representative of the underlying population of children in the United States under the age of 5. This is a problem in much of the existing developmental cognitive neuroscience research. We discussed challenges to the generalizability of our findings to the population at large. This is particularly important given that our theory is largely contextual, suggesting that children's unique experiences with learning labels for visual dimensions will impact EF development. Second, we identified a learning mechanism to target in future intervention research; however, it is not clear whether such interventions would benefit all children or how to identify children who would benefit most from such interventions. We also discuss prospective lines of research that can address these limitations, such as targeting families that are typically underrepresented in research, expanding longitudinal studies to examine longer term outcomes such as school-readiness and academic skills, and using the dynamic field (DF) model to systematically explore how exposure to objects and labels can optimize the neural representations underlying dimensional label learning. Future work remains to understand how such learning processes come to define the contextually and culturally specific skills that emerge over development and how these skills lay the foundation for broad developmental trajectories.

Interventions to improve executive functions in children aged 3 years and under: A systematic review

BACKGROUND

Early executive functioning (EF) skills are foundational capabilities that predict school readiness, academic development and psychiatric risk. Early interventions enhancing these capabilities could have critical import in improving outcomes. However, to develop interventions, it is necessary to identify specific EF skills that will vary with child age. Thus, we aimed to examine the characteristics and efficacy of interventions targeting EF in infancy and early childhood up to age 3.

METHODS

A comprehensive search of PubMed, Embase, CINAHL and APA PsycINFO databases was performed for studies published before December 2022. Randomized and non-randomized studies of interventions designed to improve at least one EF skill in children ≤3 years were included. EF skills included attentional control, inhibition/self-regulation, activity initiation, working memory, cognitive flexibility, planning ability, problem-solving and performance monitoring. We independently extracted data, used the revised Cochrane Risk-of-Bias tool to assess the quality of the evidence and conducted Synthesis Without Meta-analysis (SWiM). The overall quality of the evidence and the strength of recommendations was determined using elements of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

RESULTS

Thirty-five studies met inclusion criteria (original n = 7467). Studies were highly variable in the EF skill targeted, target subject (i.e., child, parent and teacher), nature and dosage of the intervention, and timing of outcome assessment. Most interventions focused on improving impulse control and self-regulation. The overall quality of evidence was low to moderate with a high risk of bias, though six studies had low risk of bias but yielded mixed findings of efficacy.

CONCLUSIONS

The relatively small number of early EF intervention studies uses such variable methods that there is currently no converging evidence of efficacy to recommend a specific intervention. Thus, findings support the need for a more systematic, targeted approach to the design and implementation of early EF interventions for target populations.

How do 3-year-olds do on the NIH Toolbox Cognitive Battery?

The NIH Toolbox includes a cognitive battery that provides an Early Childhood Composite score for children age 3-7. However, very few studies have evaluated feasibility when it is used in the youngest segment of this age range-3-year-olds. The current study evaluated performance on the four cognitive subtests composing the early childhood composite, two of which assess executive function, in a large sample of 3-year-olds enrolled in a Vanguard pilot of the National Children's Study. Results found that in a cohort of 609 3-year-olds (mean age = 39.6 months, SD = 1.6, 53% male, 64% White, 87% Non-Hispanic) who were administered four subtests included in the Early Childhood Composite, up to approximately 30% were unable to pass practice items on the Flanker, Dimensional Change Card Sort, and Picture Sequence Memory, whereas only approximately 3% were unable to pass practice items on the Picture Vocabulary Test. Furthermore, of those that did pass practice and achieve scores on the subtests, approximately 70% and 80% performed at or below chance level on the executive function tasks (Flanker and Dimensional Change Card Sort) and Picture Sequence Memory, respectively. Ultimately, the average 3-year-old has difficulty with three of the four NIH Toolbox tasks composing the Early Childhood Composite and may not yet have developed the requisite skills. These findings indicate that changes compatible with the developmental level of preschoolers are recommended to increase the feasibility and effectiveness of the NIH Toolbox in measuring individual cognition differences in 3-year-old children.

What are the kids doing? Exploring young children's activities at home and relations with externally cued executive function and child temperament

Young children spend a lot of time at home, yet there is little empirical research on how they spend that time and how it relates to developmental outcomes. Prior research suggests less-structured time-where children practice making choices and setting goals-may develop self-directed executive function in 6-year-olds. But less-structured time may be related to executive function for other reasons-for example, because it provides opportunities to acquire conceptual knowledge relevant to using executive function on tasks. We thus tested the possibility that less-structured time is also related to younger children's externally cued executive function. In this remote online study, caregivers of 93 3- to 5-year-olds indicated the amount of time their child was typically spending in various activities while at home during the early phase of the COVID-19 pandemic. Activities were categorized as structured (primarily lessons with specific goals defined by adults or an app), less-structured (wide range of activities permitting choice and interaction with caregiver), passive (e.g., watching TV or videos), and primarily physical (e.g., bike riding). Children's externally cued executive function was assessed via the Dimensional Change Card Sort (DCCS). Time and variety in less-structured activities were related to successful switching on the DCCS, controlling for age, family income, caregiver education, and verbal knowledge. Caregivers were more involved in less-structured versus structured activities. Caregiver ratings of children's temperament were related to how children's time was spent. These findings suggest several new avenues for studying young children's activities at home and their relations with developmental outcomes. A video abstract of this article can be viewed at https://youtu.be/3aGmpSnjuCs.

Dimensional label learning contributes to the development of executive functions

A key to understanding how the brain develops is to understand how learning can change brain function. One index of learning that takes place in early childhood involves the comprehension and production of labels describing the shape and color features of objects, a process known as dimensional label learning (DLL). DLL requires integrating auditory and visual stimuli to form a system of mappings that link label representations (e.g. "red" and "color") and visual feature representations (e.g. "red" and the hue red). Children gain expertise with these labels between the ages of 2 and 5 years, and at the same time they begin to demonstrate skills in using labels to guide cognitive function in other domains. For example, one of the hallmark measures of executive function development requires children to use verbally instructed rules to guide attention to visual dimensions. The broader impact of DLL, however, has not yet been explored. Here, we examine how the neural processes associated with the comprehension and production of labels for visual features predicts later performance on executive function tasks. Specifically, we show that left frontal cortex is activated during comprehension and production tasks at 33 months of age. Moreover, we find that neural activation in this region during label production at 33 months is associated with dimensional attention, but not spatial selective attention, at 45 months. These results shed new light on the role of label learning in developmental changes in brain and behavior. Moreover, these data suggest that dimensional label learning generalizes beyond the learned information to influence other aspects of cognition. We anticipate that these results may serve as a starting point for future work to implement label training as an intervention to influence later cognition.

Category structure guides the formation of neural representations

Perceptual variability is often viewed as having multiple benefits in object learning and categorization. Despite the abundant results demonstrating benefits such as increased transfer of knowledge, the neural mechanisms underlying variability as well as the developmental trajectories of how variability precipitates changes to category boundaries are unknown. By manipulating an individual's exposure to variability of novel, metrically organized categories during an fMRI-adaptation paradigm, we were able to assess the functional differences between similarity and variability in category learning and generalization across two time-points in development: adulthood (n = 14) and late childhood (n = 13). During this study, participants were repeatedly exposed to category members from different distributions. After a period of adaptation, a deviant stimulus that differed from the expected distribution was then presented. This deviant differed in either an invariant dimension (a feature that remained consistent throughout presentation was altered) or a similarity dimension (a feature that changed throughout exposure was changed in a new dimension). Our results can be summarized in three main findings: (1) Variability during exposure recruited the right fusiform gyrus to a greater extent than tight exposure. (2) Deviant items were generalized based on the exemplar distributions during exposure, although children only generalized items if provided variable exposure. (3) Variability influenced release to a greater extent in children than adults. These results are discussed in relation to the variability and category learning literature more broadly.

How do neural processes give rise to cognition? Simultaneously predicting brain and behavior with a dynamic model of visual working memory

There is consensus that activation within distributed functional brain networks underlies human thought. The impact of this consensus is limited, however, by a gap that exists between data-driven correlational analyses that specify where functional brain activity is localized using functional magnetic resonance imaging (fMRI), and neural process accounts that specify how neural activity unfolds through time to give rise to behavior. Here, we show how an integrative cognitive neuroscience approach may bridge this gap. In an exemplary study of visual working memory, we use multilevel Bayesian statistics to demonstrate that a neural dynamic model simultaneously explains behavioral data and predicts localized patterns of brain activity, outperforming standard analytic approaches to fMRI. The model explains performance on both correct trials and incorrect trials where errors in change detection emerge from neural fluctuations amplified by neural interaction. Critically, predictions of the model run counter to cognitive theories of the origin of errors in change detection. Results reveal neural patterns predicted by the model within regions of the dorsal attention network that have been the focus of much debate. The model-based analysis suggests that key areas in the dorsal attention network such as the intraparietal sulcus play a central role in change detection rather than working memory maintenance, counter to previous interpretations of fMRI studies. More generally, the integrative cognitive neuroscience approach used here establishes a framework for directly testing theories of cognitive and brain function using the combined power of behavioral and fMRI data. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

A Dynamical Reconceptualization of Executive-Function Development

Executive function plays a foundational role in everyday behaviors across the life span. The theoretical understanding of executive-function development, however, is still a work in progress. Doebel proposed that executive-function development reflects skills using control in the service of behavior-using mental content such as knowledge and beliefs to guide behavior in a context-specific fashion. This liberating view contrasts with modular views of executive function. This new view resembles some older dynamic-systems concepts that long ago proposed that behavior reflects the assembly of multiple pieces in context. We dig into this resemblance and evaluate what else dynamic-systems theory adds to the understanding of executive-function development. We describe core dynamic-systems concepts and apply them to executive function-as conceptualized by Doebel-and through this lens explain the multilevel nature of goal-directed behavior and how a capacity to behave in a goal-directed fashion across contexts emerges over development. We then describe a dynamic systems model of goal-directed behavior during childhood and, finally, address broader theoretical implications of dynamic-systems theory and propose new translational implications for fostering children's capacity to behave in a goal-directed fashion across everyday contexts.

Improving Dimensional Change Card Sort Performance of Preschoolers With Developmental Language Disorder: Effects of Two Task Variations

Purpose This research note addresses whether task administration variations can improve Dimensional Change Card Sort (DCCS) performance in preschoolers with developmental language disorder (DLD). Method Participants included preschoolers with DLD who failed the standard DCCS, which is characterized by inability to switch from one card sorting rule to a new rule. After an approximately 2.5-month delay, participants were retested on the DCCS in one of three conditions: repeating standard administration, participants labeling relevant card dimensions, or briefly removing target cards before the switch. Results Children in both the labeling and target removal conditions scored significantly higher on the second administration relative to the first. However, comparing across conditions, participants in the target removal condition scored higher on the second DCCS compared to participants in the standard and labeling conditions, which did not differ from each other. Conclusions DCCS performance of preschoolers with DLD can be improved by changing task administration. The most effective change is increasing the salience of the switch to the new sorting rule, as opposed to directing children's attention via their own labeling behavior.

Multidimensional Reasoning Can Promote 3-Year-Old Children's Performance on the Dimensional Change Card Sort Task

An important aspect of executive functioning is the ability to flexibly switch between behavioral rules. This study explored how considering the multidimensionality of objects affects behavioral rule switching in 3-year-old children. In Study 1 (N = 40), children who participated in a brief game separating and aggregating an object's dimensions (i.e., color and shape) showed improved performance on the Dimensional Change Card Sort (DCCS), a measure of behavioral rule switching, relative to controls. In Study 2 (N = 80) DCCS performance improved even when the initial practice involved a different dimension (pattern and shape). Thus, practice thinking about multidimensionality can affect 3-year-olds' DCCS performance and therefore may play an important role in the development of flexible thinking.

A Functional Near-Infrared Spectroscopy Examination of the Neural Correlates of Cognitive Shifting in Dimensional Change Card Sort Task

This study aims to examine the neural correlates of cognitive shifting during the Dimensional Change Card Sort Task (DCCS) task with functional near-infrared spectroscopy. Altogether 49 children completed the DCCS tasks, and 25 children (Mage = 68.66, SD = 5.3) passing all items were classified into the Switch group. Twenty children (M age = 62.05, SD = 8.13) committing more than one perseverative errors were grouped into the Perseverate group. The Switch group had Brodmann Area (BA) 9 and 10 activated in the pre-switch period and BA 6, 9, 10, 40, and 44 in the post-switch period. In contrast, the Perseverate group had BA 9 and 10 activated in the pre-switch period and BA 8, 9, 10 in the post-switch period. The general linear model results afford strong support to the "V-shape curve" hypothesis by identifying a significant decrease-increase cycle in BA 9 and 44, the neural correlations of cognitive shifting.

It is all relative: Contextual influences on boredom and neural correlates of regulatory processes

Interest in the influences on and strategies to mitigate boredom has grown immensely. Boredom emerges in contexts in which people have difficulty paying attention, such as underchallenging relative to optimally challenging conditions. The current study probed contextual influences on peoples' experience of boredom by manipulating the order with which people performed easy and optimally challenging conditions of a task (N = 113). We measured frontal alpha asymmetry (FAA) and theta/beta as neural correlates of self-regulatory and attentional control processes, respectively. Results showed self-reported boredom was higher in the easy condition when the optimal condition was completed before it. Similarly, participant's FAA shifted rightward from the first to the second task when the optimal condition was completed prior to the easy condition, indicating that self-regulatory processes were strongly engaged under these context-specific conditions. Theta/beta was lower during the easy relative to the optimal condition, regardless of the task order, indicating that maintaining attention in the easy condition was more difficult. No relations between perceptions of the task and neural correlates were observed. Exploratory analyses revealed higher levels of variability in FAA and theta/beta were associated with less enjoyment and more boredom, respectively. We speculate these observations reflect the less consistent engagement of self-regulatory and attentional control and, in turn, might play a role in peoples' subjective experience. We discuss the implications of our findings for our understanding of influences on and strategies to mitigate boredom, as well as how attentional and self-regulatory processes operate under conditions boredom typically emerges.

Not all labels develop equally: The role of labels in guiding attention to dimensions

The emergence of cognitive flexibility is a central aspect of cognitive development during early childhood. Cognitive flexibility is often probed using verbal rules to instruct behavior. In this study, the types of labels that were provided during instruction were manipulated. In one condition, children were instructed in the standard manner with dimensional labels (e.g., "shape") and featural labels (e.g., "star"). In a second condition, children were provided only with dimensional labels. When switching to color, 4-year-olds performed equally well regardless of the type of instruction. However, when switching to shape, children perseverated at a significantly higher rate when only dimensional labels were provided. These results suggest that children's understanding of labels is a critical aspect of developing cognitive flexibility and that their understanding of the labels "shape" and "color" are different.

The sampling precision of research in five major areas of psychology

After obtaining a sample of published, peer-reviewed articles from journals with high and low impact factors in social, cognitive, neuro-, developmental, and clinical psychology, we used a priori equations recently derived by Trafimow (Educational and Psychological Measurement, 77, 831-854, 2017; Trafimow & MacDonald in Educational and Psychological Measurement, 77, 204-219, 2017) to compute the articles' median levels of precision. Our findings indicate that developmental research performs best with respect to precision, whereas cognitive research performs the worst; however, none of the psychology subfields excelled. In addition, we found important differences in precision between journals in the upper versus lower echelons with respect to impact factors in cognitive, neuro-, and clinical psychology, whereas the difference was dramatically attenuated for social and developmental psychology. Implications are discussed.

Multisensory stimuli enhance 3-year-old children's executive function: A three-dimensional object version of the standard Dimensional Change Card Sort

A three-dimensional object version of the standard Dimensional Change Card Sort (DCCS) was developed to examine the influence of multisensory stimuli on 3-year-old children's executive function. Whereas the developmental phenomenon marking 3-year-olds' difficulties with rule use in the standard DCCS can be attributed to several cognitive factors, we examined the possibility that better encoding of object features could facilitate children's rule-switching behavior. We examined whether 3-year-olds might be able to capitalize on cues available to multiple senses to create a more robust representation of object features that would enable them to overcome previous difficulties with rule switching in the standard DCCS. Participants were randomly assigned to the standard two-dimensional DCCS or the three-dimensional object version that was designed to match the rabbit and boat images used in the card version. The 3-year-olds who completed the object version outperformed those who completed the standard card version, succeeding in switching rules more accurately when provided with visual, auditory-verbal labeling, and tactile information of object features. Notably, more children achieved perfect accuracy and fewer children achieved floor-level performance in the object version than in the card version. We attribute 3-year-olds' success in the object version to greater cognitive control made possible by the enhanced encoding of the stimulus properties through multisensory input and enhanced cognitive processing of ecologically valid three-dimensional objects.

Dimensional attention as a mechanism of executive function: Integrating flexibility, selectivity, and stability

In this report, we present a neural process model that explains visual dimensional attention and changes in visual dimensional attention over development. The model is composed of an object representation system that binds visual features such as shape and color to spatial locations and a label learning system that associates labels such as "color" or "shape" with visual features. We have previously demonstrated that this model explains the development of flexible dimensional attention in a task that requires children to switch between shape and color rules for sorting cards. In the model, the development of flexible dimensional attention is a product of strengthening associations between labels and features. In this report, we generalize this model to also explain development of stable and selective dimensional attention. Specifically, we use the model to explain a previously reported developmental association between flexible dimensional attention and stable dimensional attention. Moreover, we generate predictions regarding developmental associations between flexible and selective dimensional attention. Results from an experiment with 3- and 4-year-olds supported model predictions: children who demonstrated flexibility also demonstrated higher levels of selectivity. Thus, the model provides a framework that integrates various functions of dimensional attention, including implicit and explicit functions, over development. This model also provides new avenues of research aimed at uncovering how cognitive functions such as dimensional attention emerge from the interaction between neural dynamics and task structure, as well as understanding how learning dimensional labels creates changes in dimensional attention, brain activation, and neural connectivity.

Neural substrates of early executive function development

In the last decade, advances in neuroimaging technologies have given rise to a large number of research studies that investigate the neural underpinnings of executive function (EF). EF has long been associated with the prefrontal cortex (PFC) and involves both a unified, general element, as well as the distinct, separable elements of working memory, inhibitory control and set shifting. We will highlight the value of utilising advances in neuroimaging techniques to uncover answers to some of the most pressing questions in the field of early EF development. First, this review will explore the development and neural substrates of each element of EF. Second, the structural, anatomical and biochemical changes that occur in the PFC during infancy and throughout childhood will be examined, in order to address the importance of these changes for the development of EF. Third, the importance of connectivity between regions of the PFC and other brain areas in EF development is reviewed. Finally, throughout this review more recent developments in neuroimaging techniques will be addressed, alongside the implications for further elucidating the neural substrates of early EF development in the future.

Changes in frontal and posterior cortical activity underlie the early emergence of executive function

Executive function (EF) is a key cognitive process that emerges in early childhood and facilitates children's ability to control their own behavior. Individual differences in EF skills early in life are predictive of quality-of-life outcomes 30 years later (Moffitt et al., 2011). What changes in the brain give rise to this critical cognitive ability? Traditionally, frontal cortex growth is thought to underlie changes in cognitive control (Bunge & Zelazo, 2006; Moriguchi & Hiraki, 2009). However, more recent data highlight the importance of long-range cortical interactions between frontal and posterior brain regions. Here, we test the hypothesis that developmental changes in EF skills reflect changes in how posterior and frontal brain regions work together. Results show that children who fail a "hard" version of an EF task and who are thought to have an immature frontal cortex, show robust frontal activity in an "easy" version of the task. We show how this effect can arise via posterior brain regions that provide on-the-job training for the frontal cortex, effectively teaching the frontal cortex adaptive patterns of brain activity on "easy" EF tasks. In this case, frontal cortex activation can be seen as both the cause and the consequence of rule switching. Results also show that older children have differential posterior cortical activation on "easy" and "hard" tasks that reflects continued refinement of brain networks even in skilled children. These data set the stage for new training programs to foster the development of EF skills in at-risk children.

Empirical Tests of a Brain-Based Model of Executive Function Development

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 4-year-olds pass. Three predictions of the model are tested to help 3-year-olds (N = 54) pass. Experiment 1 shows that experience with shapes and the label "shape" helps children. Experiment 2 shows that experience with colors-without a label-helps children. Experiment 3 shows that experience with colors induces dimensional attention. The implications of this work for early intervention are discussed.

Developmental improvements in the resolution and capacity of visual working memory share a common source

The nature of visual working memory (VWM) representations is currently a source of debate between characterizations as slot-like versus a flexibly-divided pool of resources. Recently, a dynamic neural field model has been proposed as an alternative account that focuses more on the processes by which VWM representations are formed, maintained, and used in service of behavior. This dynamic model has explained developmental increases in VWM capacity and resolution through strengthening excitatory and inhibitory connections. Simulations of developmental improvements in VWM resolution suggest that one important change is the accuracy of comparisons between items held in memory and new inputs. Thus, the ability to detect changes is a critical component of developmental improvements in VWM performance across tasks, leading to the prediction that capacity and resolution should correlate during childhood. Comparing 5- to 8-year-old children's performance across color discrimination and change detection tasks revealed the predicted correlation between estimates of VWM capacity and resolution, supporting the hypothesis that increasing connectivity underlies improvements in VWM during childhood. These results demonstrate the importance of formalizing the processes that support the use of VWM, rather than focusing solely on the nature of representations. We conclude by considering our results in the broader context of VWM development.

Impact of Reminders on Children's Cognitive Flexibility, Intrinsic Motivation, and Mood Depends on Who Provides the Reminders

Reminding children to think about alternatives is a strategy adults often use to promote children's cognitive flexibility, as well as children's engagement in and enjoyment of the task. The current study investigated whether the impacts of reminders on kindergarten children's cognitive flexibility, intrinsic motivation, and mood are moderated by who provides the reminders. Eighty-three healthy 5-year-old kindergarten children were randomly assigned to 2 (Reminder: no reminders vs. Reminders) × 2 (Agent: Tester vs. Partner) conditions. Children's cognitive flexibility was measured via the Block Sorting Task (Garton and Pratt, 2001; Fawcett and Garton, 2005). Children reported their motivation and mood before Block Sorting, after practicing for Block Sorting, and after the actual Block Sorting. Children's intrinsic motivation was measured by evaluating children's choices during a period of free play after Block Sorting. The results revealed that, depending on who provides the reminders, reminding children of alternatives can influence kindergarten children's performance on Block Sorting, children's intrinsic motivation, and children's self-reported mood.