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Executive function (EF) and language are correlated in the preschool years, but the causal role that language plays in EF development remains unclear. The present study sheds light on this topic by comparing EF development among children who are typically hearing (TH) and deaf or hard-of-hearing (DHH). Oral DHH children’s access to spoken language is delayed until they receive a cochlear implant or other device, providing a sort of natural experiment on how language impacts cognitive development. We expected that, if language does contribute to EF development, then (1) TH children should outperform DHH children on the EF task, and that (2) length of language access should account for this difference in performance. Preschoolers (n = 108, 38 oral DHH and 70 TH children, 3.0-6.5 years) completed a nonverbal rule-switching task measuring inhibitory control. Confirming our first hypothesis, a linear regression revealed that oral DHH children performed significantly worse on this task. We also directly confirmed that delayed language access accounted for these EF delays; we obtained data on the age at which each oral DHH child first received an auditory device (range 1.5-48 months), allowing us to compute length of language access. Mediation models revealed that length of language access fully mediated the link between hearing status (DHH/hearing) and EF, confirming our second hypothesis. Implications for theories of EF development are discussed, along with implications for DHH children, whose cognitive development is constrained by their access to language rather than their intrinsic abilities.

Studies on children’s understanding of counting examine when and how children acquire the cardinal principle: the idea that the last word in a counted set reflects the cardinal value of the set. Using Wynn’s (1990) Give-N Task, researchers classify children who can count to generate large sets as having acquired the cardinal principle (cardinal-principle-knowers) and those who cannot as lacking knowledge of it (subset-knowers). However, recent studies have provided a more nuanced view of number word acquisition. Here, we explore this view by examining the developmental progression of the counting principles with an aim to elucidate the gradual elements that lead to children successfully generating sets and being classified as CP-knowers on the Give-N Task. Specifically, we test the claim that subset-knowers lack cardinal principle knowledge by separating children’s understanding of the cardinal principle from their ability to apply and implement counting procedures. We also ask when knowledge of Gelman & Gallistel’s (1978) other how-to-count principles emerge in development. We analyzed how often children violated the three how-to-count principles in a secondary analysis of Give-N data (N = 86). We found that children already have knowledge of the cardinal principle prior to becoming CP-knowers, and that understanding of the stable-order and word-object correspondence principles likely emerged earlier. These results suggest that gradual development may best characterize children’s acquisition of the counting principles, and that learning to coordinate all three principles represents an additional step beyond learning them individually.

We agree that the approximate number system (ANS) truly represents number. We endorse the authors' conclusions on the arguments from confounds, congruency, and imprecision, although we disagree with many claims along the way. Here, we discuss some complications with the meanings that undergird theories in numerical cognition, and with the language we use to communicate those theories.

Split reporter protein-based genetic section systems are widely used to identify and characterize protein–protein interactions (PPI). The assembly of split markers that antagonize toxins, rather than required for synthesis of missing metabolites, facilitates the seeding of high density of cells and selective growth. Here we present a newly developed split chloramphenicol acetyltransferase (split-CAT) -based genetic selection system. The N terminus fragment of CAT is fused downstream of the protein of interest and the C terminus fragment is tethered upstream to its postulated partner. We demonstrate the system's advantages for the study of PPIs. Moreover, we show that co-expression of a functional ubiquitylation cascade where the target and ubiquitin are tethered to the split-CAT fragments results in ubiquitylation-dependent selective growth. Since proteins do not have to be purified from the bacteria and due to the high sensitivity of the split-CAT reporter, detection of challenging protein cascades and post-translation modifications is enabled. In addition, we demonstrate that the split-CAT system responds to small molecule inhibitors and molecular glues (GLUTACs). The absence of ubiquitylation-dependent degradation and deubiquitylation in E. coli significantly simplify the interpretation of the results. We harnessed the developed system to demonstrate that like NEDD4, UBE3B also undergoes self-ubiquitylation-dependent inactivation. We show that self-ubiquitylation of UBE3B on K665 induces oligomerization and inactivation in yeast and mammalian cells respectively. Finally, we showcase the advantages of split-CAT in the study of human diseases by demonstrating that mutations in UBE3B that cause Kaufman oculocerebrofacial syndrome exhibit clear E. coli growth phenotypes.

Children learn to count, and even learn the cardinal meanings of the first three or four verbal numerals ("one" through "three" or "four"), before they master the numerical significance of counting. If so, it follows that the cardinal meanings of those first few numerals cannot be derived, initially, from their place in the count list and the counting routine. What non-verbal representations, then, support the cardinal meanings of verbal numerals before children have mastered how counting does so? Four experiments addressed the commonly adopted assumption that in the earliest period of learning the meanings of number words, children map verbal numerals to regions of the analog number system (ANS), a system of representation with numerical content that is widely attested in animals and in human infants. Experiment 1 confirmed that children who know what "three" means, but who do not yet know what "four" means, and do not yet know how counting represents number, can be easily taught the meaning of "four," if they are trained to indicate sets of four when they are paired with a series of sets that contrast numerically with four. If children learn "four" by mapping the word to an ANS representation of sets of four, and if such ANS value-to-word mappings underlie the meanings of other known numerals early in development, then analogous teaching should enable young children to establish a ANS value-to-word mapping for between "ten" and sets of 10 as specified by the ANS. Furthermore, the ease of learning should be a function of the ratio of the number of individuals in the comparison set to 10. Three further experiments tested these hypotheses by attempting to teach young Cardinal Principle-knowers the meaning of the word "ten," under the same training conditions "three-"knowers are easily taught the meaning of "four". The children learned which picture in each training pair had "ten." However, test trials with novel animals and spatial configurations showed that they had failed to learn what set sizes should be labeled "ten", even when, after training, they were asked to indicate a set of 10 vs. a set of 20 or 30 (well within the ratio sensitivity of the ANS even early in infancy). Furthermore, there was no effect of ratio on success during test trials. These data provide new evidence that ANS value-to-word mappings do not underlie the meanings of number words early in development. We discuss what other non-verbal representations might do so, and discuss other ways the ANS may support learning how counting represents number.

The acquisition of counting is a major milestone for children. A central question is how children’s non-verbal number concepts change as they learn to count. We assessed children’s verbal counting knowledge using the Give-N task and identified children who had acquired the cardinal principle (Cardinal Principle Knowers, or CP-knowers) and those who had not (Subset-Knowers, or SS-knowers). We compared their performance on two tests of nonverbal numerical cognition. We report comparable performance between SS- and CP-knowers for matching and tracking small sets of objects up to four, but disparate performance for sets between five and nine, with CP-knowers outperforming SS-knowers. These results indicate that the difference between CP- and SS-knowers extends beyond their knowledge of the verbal number system to their non-verbal quantitative reasoning. The findings provide support for the claim that children’s induction of cardinality represents a conceptual transition with concurrent, qualitative changes in numerical representation.

As a field, developmental science has embarked on the serious work of translating research findings for use in real world settings, but much research from developmental scientists remains cloistered within university walls. This paper presents a framework for the translation of developmental science to practice, mostly in educational settings, articulating ten core principles for bridging the research-to-practice gap. The principles summarize the key lessons learned from two long-term research-to-practice translational projects: the development of an early childhood numeracy curriculum (the Wesleyan Preschool Math Project) and a research-based summer pre-K for low-income children (Kindergarten Kickstart). The principles (1. Understand the gap; 2. Invest in developing the intervention; 3. Appreciate the naturalistic, real-world context; 4. Maximize uptake, not just efficacy and effectiveness; 5. Acknowledge power and status differentials; 6. Collaborate; 7. Leverage resources; 8. Respect; 9. Practice iterative development; 10. Simplify the final product) reflect central tenets of community-engaged research and intervention design; we emphasize the importance of collaborating with community members; acknowledging power differentials between researchers and practitioners; respecting practitioners as experts in their own right with valuable insight into their classrooms; appreciating naturalistic context; and recognizing the motivations of end-users at every step of intervention design and development. The paper also includes strategies for researchers to maximize opportunities to translate research to practice, such as leveraging untapped resources and mobilizing undergraduate students. This paper is both a call to action and an initial blueprint for developmental scientists who are interested in translating more research into practice.

About one-third of the eukaryotic proteome undergoes ubiquitylation, but the enzymatic cascades leading to substrate modification are largely unknown. We present a genetic selection tool that utilizes Escherichia coli, which lack deubiquitylases, to identify interactions along ubiquitylation cascades. Coexpression of split antibiotic resistance protein tethered to ubiquitin and ubiquitylation target together with a functional ubiquitylation apparatus results in a covalent assembly of the resistance protein, giving rise to bacterial growth on selective media. We applied the selection system to uncover an E3 ligase from the pathogenic bacteria EHEC and to identify the epsin ENTH domain as an ultraweak ubiquitin-binding domain. The latter was complemented with a structure-function analysis of the ENTH-ubiquitin interface. We also constructed and screened a yeast fusion library, discovering Sem1 as a novel ubiquitylation substrate of Rsp5 E3 ligase. Collectively, our selection system provides a robust high-throughput approach for genetic studies of ubiquitylation cascades and for small-molecule modulator screening.

Recent developmental research demonstrates that group bias emerges early in childhood. However, little is known about the extent to which bias in minimal (i.e., arbitrarily assigned) groups varies with children's environment and experience, and whether such bias is universal across cultures. In this study, the development of group bias was investigated using a minimal groups paradigm with 46 four- to six-year-olds from the Faroe Islands. Children observed in-group and out-group members exhibiting varying degrees of prosocial behaviour (egalitarian or stingy sharing). Children did not prefer their in-group in the pretest, but a pro-in-group and anti-out-group sentiment emerged in both conditions in the posttest. Faroese children's response patterns differ from those of American children [Schug, M. G., Shusterman, A., Barth, H., & Patalano, A. L. (2013). Minimal-group membership influences children's responses to novel experience with group members. Developmental Science, 16(1), 47–55], suggesting that intergroup bias shows cultural variation even in a minimal groups context.

Ubiquitylation is an eukaryotic signal that regulates most cellular pathways. However, four major hurdles pose challenges to study ubiquitylation: (1) high redundancy between ubiquitin (Ub) cascades, (2) ubiquitylation is tightly regulated in the cell, (3) the transient nature of the Ub signal, and (4) difficulties to purify functional ubiquitylation apparatus for in vitro assay. Here, we present systems that express functional Ub cascades in E. coli, which lacks deubiquitylases, Ub-dependent degradations, and control mechanisms for ubiquitylation. Therefore, expression of an ubiquitylation cascade results in the accumulation of stable ubiquitylated protein that can be genetically selected or purified, thus circumventing the above challenges. Co-expression of split antibiotic resistance protein fragments tethered to Ub and ubiquitylation targets along with ubiquitylation enzymes (E1, E2, and E3) gives rise to bacterial growth on selective media. We show that ubiquitylation rate is highly correlated with growth efficiency. Hence, genetic libraries and simple manipulations in the selection system facilitate the identification and characterization of components and interfaces along Ub cascades. The bacterial expression system also facilitates the detection of ubiquitylated proteins. Furthermore, the expression system allows affinity chromatography-based purification of milligram quantities of ubiquitylated proteins for downstream biochemical, biophysical, and structural studies.

The hippocampus is a subcortical structure in the medial temporal lobe involved in cognitive functions such as spatial navigation and reorientation, episodic memory, and associative learning. While much is understood about the role of hippocampal function in learning and memory in adults, less is known about the relations between the hippocampus and the development of these cognitive skills in young children due to the limitations of using standard methods (e.g., MRI) to examine brain structure and function in developing populations. This study used hippocampal-dependent trace eyeblink conditioning (EBC) as a feasible approach to examine individual differences in hippocampal functioning as they relate to spatial reorientation and episodic memory performance in young children. Three- to six-year-old children (N = 50) completed tasks that measured EBC, spatial reorientation, and episodic memory, as well as non-hippocampal-dependent processing speed abilities. Results revealed that when age was held constant, individual differences in EBC performance were significantly related to individual differences in performance on the spatial reorientation test, but not on the episodic memory or processing speed tests. When the relations between hippocampal-dependent EBC and different reorientation strategies were explored, it was found that individual differences in hippocampal function predicted the use of geometric information for reorienting in space as opposed to a combined strategy that uses both geometric information and salient visual cues. The utilization of eyeblink conditioning to examine hippocampal function in young populations and its implications for understanding the dissociation between spatial reorientation and episodic memory development are discussed.

Ubiquitylation is an eukaryotic signal that regulates most cellular pathways. However, four major hurdles pose challenges to study ubiquitylation: (1) high redundancy between ubiquitin (Ub) cascades, (2) ubiquitylation is tightly regulated in the cell, (3) the transient nature of the Ub signal, and (4) difficulties to purify functional ubiquitylation apparatus for in vitro assay. Here, we present systems that express functional Ub cascades in E. coli, which lacks deubiquitylases, Ub-dependent degradations, and control mechanisms for ubiquitylation. Therefore, expression of an ubiquitylation cascade results in the accumulation of stable ubiquitylated protein that can be genetically selected or purified, thus circumventing the above challenges. Co-expression of split antibiotic resistance protein fragments tethered to Ub and ubiquitylation targets along with ubiquitylation enzymes (E1, E2, and E3) gives rise to bacterial growth on selective media. We show that ubiquitylation rate is highly correlated with growth efficiency. Hence, genetic libraries and simple manipulations in the selection system facilitate the identification and characterization of components and interfaces along Ub cascades. The bacterial expression system also facilitates the detection of ubiquitylated proteins. Furthermore, the expression system allows affinity chromatography-based purification of milligram quantities of ubiquitylated proteins for downstream biochemical, biophysical, and structural studies.

Purpose The goals of this study were to (1) measure psychological, physiological, and behavioral indicators of stress, (2) assess the relationship between stress and student attitudes, and (3) explore coping behaviors in response to stress, among a sample of students in two academically high-achieving environments. Method Three hundred thirty-three students in grades 9 through 12 from two college-preparatory high schools completed a cross-sectional online survey that included the Students' Life Satisfaction Scale, School Attitude Assessment Questionnaire-Revised, and assessments for stress-related indicators, including eating, sleeping and exercise, and strategies they utilized for coping with stress. Results Students reported a high prevalence of physical and psychological correlates of stress, and related unhealthy behaviors such as widespread and chronic sleep deprivation and rushed meals. Conclusions The results suggest areas to focus attention for identifying and addressing maladaptive responses to stress among high-achieving student populations.

Children, like adults, tend to prefer ingroup over outgroup individuals, but how this group bias affects children's processing of information about social groups is not well understood. In this study, 5- and 6-year-old children were assigned to artificial groups. They observed instances of ingroup and outgroup members behaving in either a positive (egalitarian) or a negative (stingy) manner. Observations of positive ingroup and negative outgroup behaviors reliably reduced children's liking of novel outgroup members, while observations of negative ingroup and positive outgroup behaviors had little effect on liking ratings. In addition, children successfully identified the more generous group only when the ingroup was egalitarian and the outgroup stingy. These data provide compelling evidence that children treat knowledge of and experiences with ingroups and outgroups differently, and thereby differently interpret identical observations of ingroup versus outgroup members.

Language has been linked to spatial representation and behavior in humans, but the nature of this effect is debated. Here, we test whether simple verbal expressions improve 4-year-old children's performance in a disoriented search task in a small rectangular room with a single red landmark wall. Disoriented children's landmark-guided search for a hidden object was dramatically enhanced when the experimenter used certain verbal expressions to designate the landmark during the hiding event. Both a spatial expression (“I'm hiding the sticker at the red/white wall”) and a non-spatial but task-relevant expression (“The red/white wall can help you get the sticker”) enhanced children's search, relative to uncued controls. By contrast, a verbal expression that drew attention to the landmark in a task-irrelevant manner (“Look at this pretty red/white wall”) produced no such enhancement. These findings provide further evidence that language changes spatial behavior in children and illuminate one mechanism through which language exerts its effect: by helping children understand the relevance of landmarks for encoding locations.

Although spatial language and spatial cognition covary over development and across languages, determining the causal direction of this relationship presents a challenge. Here we show that mature human spatial cognition depends on the acquisition of specific aspects of spatial language. We tested two cohorts of deaf signers who acquired an emerging sign language in Nicaragua at the same age but during different time periods: the first cohort of signers acquired the language in its infancy, and 10 y later the second cohort of signers acquired the language in a more complex form. We found that the second-cohort signers, now in their 20s, used more consistent spatial language than the first-cohort signers, now in their 30s. Correspondingly, they outperformed the first cohort in spatially guided searches, both when they were disoriented and when an array was rotated. Consistent linguistic marking of left–right relations correlated with search performance under disorientation, whereas consistent marking of ground information correlated with search in rotated arrays. Human spatial cognition therefore is modulated by the acquisition of a rich language.

Physical touch has many documented benefits, but past research has paid little attention to the effects of touch on children's development. Here, we tested the effect of touch on children's compliance behaviour in a modified delay-of-gratification task. Forty children ( M = 59 months) were randomly assigned to a touch or no touch group. Children in the intervention condition received a friendly touch on the back while being told that they should wait for permission to eat a candy. Results showed that children in the touch condition waited an average of two minutes longer to eat the candy than children in the no touch condition. This finding has implications for the potential of using touch to promote positive behaviours in children.

Trichotillomania (TTM), a repetitive hair-pulling disorder, is underrepresented in the clinical literature. The current project explores the relationship between affective regulation and disordered hair-pulling. Previous research suggests that cycles of emotional states are correlated with the disorder and may induce, reinforce, or otherwise contribute to hair-pulling behavior. We use anonymous internet survey responses from 1162 self-identified hair-pullers to address four questions about affective regulation in people with TTM: (1) Do hair-pullers experience greater difficulty "snapping out" of affective states than non-pullers? (2) Does difficulty with emotional control correlate with TTM severity? (3) Are subtypes identifiable based on the emotions that trigger hair-pulling behavior? (4) Does difficulty "snapping out" of an emotion predict whether that emotion triggers pulling behavior? The results showed a small-to-moderate relationship between affective regulation and problematic hair-pulling. In addition, individual patterns of emotion regulation were systematically related to emotional cues for hair-pulling as well as overall hair-pulling severity. These findings contribute to an understanding of the phenomenology of TTM and provide empirical support for treatments focused on affect regulation.

Two experiments tested whether 4-year-old children extract and use geometric information in simple maps without task instruction or feedback. Children saw maps depicting an arrangement of three containers and were asked to place an object into a container designated on the map. In Experiment 1, one of the three locations on the map and the array was distinct and therefore served as a landmark; in Experiment 2, only angle, distance and sense information specified the target container. Children in both experiments used information for distance and angle, but not sense, showing signature error patterns found in adults. Children thus show early, spontaneously developing abilities to detect geometric correspondences between three-dimensional layouts and two-dimensional maps, and they use these correspondences to guide navigation. These findings begin to chart the nature and limits of the use of core geometry in a uniquely human, symbolic task.

Disoriented 4-year-old children use a distinctive container to locate a hidden object, but do they reorient by this information? We addressed this question by testing children's search for objects in a circular room containing one distinctive and two identical containers. Children's search patterns provided evidence that the distinctive container served as a direct cue to a hidden object's location, but not as a directional signal guiding reorientation. The findings suggest that disoriented children's search behavior depends on two distinct processes: a modular reorientation process attuned to the geometry of the surface layout and an associative process linking landmarks to specific locations.

This chapter argues that human and animal minds indeed depend on a collection of domain-specific, task-specific, and encapsulated cognitive systems: on a set of cognitive ‘modules’ in Fodor's sense. It also argues that human and animal minds are endowed with domain-general, central systems that orchestrate the information delivered by core knowledge systems. The chapter begins by reviewing the literature on spatial reorientation in animals and in young children, arguing that spatial reorientation bears the hallmarks of core knowledge and of modularity. It then considers studies of older children and adults, arguing that human spatial representations change qualitatively over development and show capacities not found in any other species. Finally, it presents two new experiments that investigate the role of emerging spatial language in uniquely human navigation performance.

Languages differ in how they encode spatial frames of reference. It is unknown how children acquire the particular frame-of-reference terms in their language (e.g., left/right, north/south). The present paper uses a word-learning paradigm to investigate 4-year-old English-speaking children’s acquisition of such terms. In Part I, with five experiments, we contrasted children’s acquisition of novel word pairs meaning left-right and north-south to examine their initial hypotheses and the relative ease of learning the meanings of these terms. Children interpreted ambiguous spatial terms as having environment-based meanings akin to north and south, and they readily learned and generalized north-south meanings. These studies provide the first direct evidence that children invoke geocentric representations in spatial language acquisition. However, the studies leave unanswered how children ultimately acquire “left” and “right.” In Part II, with three more experiments, we investigated why children struggle to master body-based frame-of-reference words. Children successfully learned “left” and “right” when the novel words were systematically introduced on their own bodies and extended these words to novel (intrinsic and relative) uses; however, they had difficulty learning to talk about the left and right sides of a doll. This difficulty was paralleled in identifying the left and right sides of the doll in a non-linguistic memory task. In contrast, children had no difficulties learning to label the front and back sides of a doll. These studies begin to paint a detailed account of the acquisition of spatial terms in English, and provide insights into the origins of diverse spatial reference frames in the world’s languages.