Sequence imitation and reaching measures of executive control: a longitudinal examination in the second year of life

From terrible twos to sassy sixes: The development of vocabulary and executive functioning across early childhood

Across the early childhood period of development, young children exhibit considerable growth in their executive functioning (EF) and vocabulary abilities. Understanding the developmental trajectory of these seemingly interrelated processes is important as both early vocabulary and EF have been shown to predict critical academic and socio-emotional outcomes later in childhood. Although previous research suggests that EF and vocabulary are correlated in early childhood, much of the existing longitudinal research has focused on unidirectional relations among preschool child samples. The current large-scale study, therefore, sought to examine whether children's vocabulary and EF abilities are bidirectionally related over time across four measurement waves in early childhood (i.e., at ages 2, 3, 4, and 6). At each timepoint, children's vocabulary skills were positively correlated with their concurrent EF abilities. After controlling for child sex and maternal education status, the best-fitting, cross-lagged panel model was a unidirectional model whereby children's early vocabulary scores predicted their later EF performance at each timepoint. Although age 2 EF significantly predicted age 3 vocabulary size, this association was no longer significant after accounting for maternal education status. Our results illustrate that vocabulary size plays an important role in predicting children's later EF performance across various timepoints in early childhood, even after controlling for children's initial EF scores. These findings have important implications for intervention research as fostering early vocabulary acquisition may serve as a possible avenue for improving EF outcomes in young children. RESEARCH HIGHLIGHTS: Children's vocabulary size is positively correlated with their concurrent executive functioning skill at ages 2, 3, 4, and 6 Young children's early vocabulary scores predict their later EF performance across measurement waves, even after controlling for initial EF skill There is stability in children's relative vocabulary size and executive functioning performance over time in early childhood.

The Development of Flexible Problem Solving: An Integrative Approach

Flexible problem solving, the ability to deal with currently goal-irrelevant information that may have been goal-relevant in previous, similar situations, plays a prominent role in cognitive development and has been repeatedly investigated in developmental research. However, this research, spanning from infancy to the school years, lacks a unifying framework, obscuring the developmental timing of flexible problem solving. Therefore, in this review paper, previous findings are gathered, organized, and integrated under a common framework to unveil how and when flexible problem solving develops. It is showed that the development of flexible problem solving coincides with increases in executive functions, that is, inhibition, working memory and task switching. The analysis of previous findings shows that dealing with goal-irrelevant, non-salient information received far more attention than generalizing in the presence of goal-irrelevant, salient information. The developmental timing of the latter can only be inferred from few transfer studies, as well as executive functions, planning and theory of mind research, to highlight gaps in knowledge and sketch out future research directions. Understanding how transfer in the presence of seemingly relevant but truly irrelevant information develops has implications for well-balanced participation in information societies, early and lifespan education, and investigating the evolutionary trajectory of flexible problem solving.

Universality and context-specificity in early executive function development

A renewed interest in early executive function (i.e., EF or the conscious control of thought and behavior) development has led several research groups to suggest that EF may be emerging and is less coordinated (e.g., showing few relations between tasks) in the first few years (Devine et al., 2019; Gago Galvagno et al., 2021; Johansson et al., 2016; Miller & Marcovitch, 2015; Ribner et al., 2022). This potentially universal development in EF does not exclude the possibility that EF may also differ across context (e.g., Gago Galvagno et al., 2021; Lohndorf et al., 2019; Tran et al., 2015) reflecting unique strengths and development built within one's sociocultural environment. The present paper explores potential universal and context-specific early EF developments by focusing on three aims: (1) reviewing work on EF within the first two years of life that may speak to potential universality in the measurement, structure, growth, stability, and conceptualization of early EF (2) reviewing research that may speak to how the sociocultural context may play a role in context-specific development within early EF and (3) examining potential developmental EF frameworks for understanding universal and context-specific developments of early EF within context.

Does parental autonomy support mediate the relation between parent and infant executive function? A study of mothers and fathers in the Netherlands and China

Parenting skills, such as Autonomy Support (AS), have been proposed as a potential mechanism explaining the intergenerational contiguity of Executive Function (EF). However, few studies have focused on mothers and fathers among non-Western families. The current study investigated the role of maternal and paternal AS in the relation between parental EF and infant EF at 14 months of age among 123 Dutch and 63 Chinese first-time mothers and fathers and their infants. Multiple-group structural equation models were built for mothers and fathers separately with country as a grouping variable. Results showed that parental AS did not mediate the relation between parent EF and infant EF at 14 months. Mean-level differences were found in parental AS, maternal EF, and infant inhibition across countries, while no country differences were found in the relation between parent EF, AS and infant EF. Our findings suggested that individual differences in early EF may not be stable enough to be reliably predicted from parental factors across the Netherlands and China.

Mothers' and fathers' executive function both predict emergent executive function in toddlerhood

There are multivariate influences on the development of children's executive function throughout the lifespan and substantial individual differences can be seen as early as when children are 1 and 2 years of age. These individual differences are moderately stable throughout early childhood, but more research is needed to better understand their origins. To some degree, individual differences in executive function are correlated between mother and child, but no research to date has examined these associations prior to when children are preschool age, nor have any studies considered the role of fathers' and mothers' executive function in tandem. Here, we use a sample of 484 families (Mothers 89.2% white; Fathers 92.5% white) in three countries (UK, USA, Netherlands) to investigate the role of each parents' executive function on the development of children's (49.7% female) executive function from 14 (M = 14.42, SD = 0.57) to 24 (M = 24.47, SD = 0.78) months, as well as parenting practices that underlie these associations. Results of structural equation models suggest stability in some-but not all-components of executive function and growing unity between components as children age. We replicate extant findings such that mothers' executive function predicts children's executive function over and above stability and extend these findings to include associations between father and child skills. We find an additive role of fathers' EF, similar in magnitude to the role of mothers' EF. Finally, for both mothers and fathers we find that sensitivity and autonomy supportive practices mediate the relations between parents' and children's executive function.

Vocabulary and Executive Functioning: A Scoping Review of the Unidirectional and Bidirectional Associations across Early Childhood

Early childhood marks a time where word learning is accompanied by rapid growth in the cognitive processes that underlie self-modulated and goal-directed behavior (i.e., executive functions). Although there is empirical evidence to support the association between executive functioning and vocabulary in childhood, inconsistent findings have been reported regarding the extent to which early executive functioning abilities predict later vocabulary outcomes and vice versa. To clarify the nature of the longitudinal relation between these two processes and to examine what, if any, claims can be made about their interdependence, a critical review of the literature was conducted. Also addressed are the conceptual and/or methodological differences that exist across studies conducted on this topic that may be contributing to some of the discrepancies reported in the longitudinal literature. Finally, this review provides practical and empirically informed future directions to serve as a resource for early childhood researchers advancing this area of study.

Emerging coherence and relations to communication among executive function tasks in toddlers: Evidence from a Latin American sample

Recent work within early executive function (EF) seems to suggest that toddlers show distinct patterns of development, involving poorly correlated performance across EF tasks and significant improvements over relatively short periods of time. The present study sought to extend these findings by investigating evidence for these patterns in toddlers and the existence of more traditional patterns of EF (e.g., correlations between tasks, links to language) when using the same tasks in a novel Latin American sample. Eighty toddlers (18-24 months) and sixty young preschoolers (30-36) months completed a battery of EF tasks, early social communication, and receptive and expressive language measures. Results indicated that toddlers showed similar distinct patterns of development (i.e., few relations between tasks and links to responding to joint attention), but by early preschool a more cohesive EF and links to language were present. Further, work demonstrated significant age (older children outperformed younger children), gender (girls outperformed boys), and socioeconomic differences (satisfied basic needs outperformed unsatisfied basic needs, but only on the snack delay). This work provides evidence for patterns of emerging EF development within this novel cultural sample (and evidence for group differences) that may be supported by communicative and representational development.

Thinking inside the box: Mental manipulation of working memory contents in 3- to 7-year-old children

We developed a non-verbal task assessing updating and manipulation of working memory contents. 80 3- to 7-year-olds (47 girls; predominantly European White) were tested with a 4 × 4 grid containing 8 boxes (in the 4 centre cells and 4 outer corners). A sticker was hidden and children searched for it after a delay phase. In the updating trials, the grid was rotated during delays, in the manipulation trials, the grid was both occluded and rotated. Rewards were hidden in either the inner or outer boxes (between-subjects design). Performance was affected by age, rotation degree and hiding condition. Performance was better in outer boxes trials, where visual tracking was easier. Occluded inner trials added a substantial cognitive load (which increased with degree of rotation), resulting in children performing at chance level, suggesting that manipulation involving mental rotation is a distinct skill from tracking invisible object displacement, with a more protracted development.

Measuring and Predicting Individual Differences in Executive Functions at 14 Months: A Longitudinal Study

This study of 195 (108 boys) children seen twice during infancy (Time 1: 4.12 months; Time 2: 14.42 months) aimed to investigate the associations between and infant predictors of executive function (EF) at 14 months. Infants showed high levels of compliance with the EF tasks at 14 months. There was little evidence of cohesion among EF tasks but simple response inhibition was related to performance on two other EF tasks. Infant attention (but not parent-rated temperament) at 4 months predicted performance on two of the four EF tasks at 14 months. Results suggest that EF skills build on simpler component skills such as attention and response inhibition.

Temperament and Cognitive Regulation During the First 3 Years of Life as Predictors of Inattention and Hyperactivity/Impulsivity at 6 Years

Objective: With a wish to identify early markers of inattention and hyperactivity/impulsivity, we examined effects of temperament and cognitive regulation, during the first 3 years of life, on later inattentive and hyperactive/impulsive behavior. Method: Temperament and cognitive regulation were assessed at 12, 18, 24, and 36 months in 66 typically developing children. Teachers rated inattention and hyperactivity/impulsivity at 6 years. Results: Temperamental activity at all studied time points was predictive of later hyperactive/impulsive behavior, thus appearing as a stable marker thereof. Activity at 12 months was also predictive of inattention, whereas temperamental persistence was correlated with inattention and hyperactivity/impulsivity, but with no independent contributions. No significant relations between cognitive regulation and the outcome measures were found. Conclusion: Our findings add to the scarce literature proposing that markers of inattentive and hyperactive/impulsive behavior in early school age can be found within the first years of life, using parental ratings of child temperament.

Two-year-olds succeed at MIT: Multiple identity tracking in 20- and 25-month-old infants

Infants' ability to remember objects and their locations emerges during the first year of life. However, not much is known about infants' ability to track objects' identities in a dynamic environment. Here, we tailored the delayed match retrieval eye-tracking paradigm to study infants' ability to track two object identities during occlusion-an infant version of multiple identity tracking (MIT). Delayed match retrieval uses virtual "cards" as stimuli that are first shown face up, exposing to-be-remembered information, and then turned face down, occluding it. Here, cards were subject to movement during the face-down occlusion period. We used complex non-nameable objects as card faces to discourage verbal rehearsal. In three experiments (N = 110), we compared infants' ability to track object identities when two previously exposed cards were static (Experiment 1), were moved into new positions along the same trajectory (Experiment 2), or were moved along different trajectories (Experiment 3) while face down. We found that 20-month-olds could remember two object identities when static; however, it was not until 25 months of age that infants could track when movement was introduced. Our results show that the ability to track multiple identities in visual working memory is present by 25 months.

Regulation During the Second Year: Executive Function and Emotion Regulation Links to Joint Attention, Temperament, and Social Vulnerability in a Latin American Sample

Although a growing body of work has established developing regulatory abilities during the second year of life, more work is needed to better understand factors that influence this emerging control. The purpose of the present study was to examine regulation capacities in executive functions (i.e., EF or cognitive control) and emotion regulation (i.e., ER or control focused on modulating negative and sustaining positive emotions) in a Latin American sample, with a focus on how joint attention, social vulnerability, and temperament contribute to performance. Sixty Latin American dyads of mothers and children aged 18 to 24 months completed several EF tasks, a Still-Face Paradigm (SFP) to examine ER (Weinberg et al., 2008), and the Early Social Communication Scale to measure joint attention (Mundy et al., 2003). Parents completed the Early Childhood Behavior Questionnaire Very Short Form to measure temperament (ECBQ-VS, Putnam et al., 2010) and the Social Economic Level Scale (SES) from INDEC (2000). Results revealed the typical responses expected for toddlers of this age in these EF tasks and in the SFP. Also, we found associations between EF and ER and between non-verbal communication related to monitoring infants’ attention to objects (i.e., responding to joint attention) and initiation of pointing (e.g., pointing and showing of an object while the child alternates his gaze to an adult) with EF. Regarding social factors, family differences and type of housing contribute to regulation. For temperament, effortful control was associated with both regulatory capacities. Finally, only age predicted EF. These results suggest that many patterns regarding the development of these abilities are duplicated in the first months of life in a Latin American sample while further highlighting the importance of considering how the environment and the individual characteristics of infants may associate to these regulatory abilities, which is particularly relevant to developing public policies to promote their optimal development.

Does child verbal ability mediate the relationship between maternal sensitivity and later self-regulation? A longitudinal study from infancy to 4 years

There is a need to further examine the mechanisms by which maternal sensitivity influences the development of child self-regulation. This study investigated the role of maternal sensitivity when infants were 10 months old and child verbal ability at 18 months, in relation to various aspects of self-regulation at 48 months, in a sample of 95 typically developing children (46.3% girls). In particular, the study examined, from a Vygotskian perspective, whether child verbal ability, as measured by receptive and expressive language, mediated the relationship between maternal sensitivity and hot and cool aspects of self-regulation in the child. As hypothesized, maternal sensitivity predicted child verbal ability, as well as working memory, set shifting, and delay of gratification. Child receptive language predicted set shifting, inhibition, and delay of gratification. In addition, receptive language mediated the relationship between maternal sensitivity and inhibition only. Additive effects of maternal sensitivity and child receptive language in relation to set shifting were found, and a main effect of maternal sensitivity on child delay of gratification. The results add to the body of research suggesting that responsive parenting and child verbal ability are important for the development of self-regulation, and suggest that different mechanisms may be at work for different aspects of self-regulation.

The role of sustained attention, maternal sensitivity, and infant temperament in the development of early self-regulation

This study investigated infant predictors of early cognitive and emotional self-regulation from an intrinsic and caregiving environmental perspective. Sustained attention, reactive aspects of infant temperament, and maternal sensitivity were assessed at 10 months (n = 124) and early self-regulation (including executive functions, EF, and emotion regulation) was assessed at 18 months. The results indicated that sustained attention predicted early EF, which provide empirical support for the hierarchical framework of EF development, advocating early attention as a foundation for the development of cognitive self-regulation. Maternal sensitivity and surgency predicted emotion regulation, in that infants of sensitive mothers showed more regulatory behaviours and a longer latency to distress, whereas high levels of surgency predicted low emotion regulation, suggesting both the caregiving environment and temperament as important in the development of self-regulation. Interaction effects suggested high sustained attention to be a protective factor for children of insensitive mothers, in relation to emotion regulation. In addition, high levels of maternal sensitivity seemed to foster development of emotion regulation among children with low to medium levels of sustained attention and/or surgency. In all, our findings point to the importance of both intrinsic and extrinsic factors in infant development of self-regulation.

Assessing Executive Functions in Preschoolers Using Shape School Task

Over the last two decades, there has been a growing interest in the study of the development of executive functions (EF) in preschool children due to their relationship with different cognitive, psychological, social and academic domains. Early detection of individual differences in executive functioning can have major implications for basic and applied research. Consequently, there is a key need for assessment tools adapted to preschool skills: Shape School has been shown to be a suitable task for this purpose. Our study uses Shape School as the main task to analyze development of inhibition, task-switching and working memory in a sample of 304 preschoolers (age range 3.25–6.50 years). Additionally, we include cognitive tasks for the evaluation of verbal variables (vocabulary, word reasoning and short-term memory) and performance variables (picture completion and symbol search), so as to analyze their relationship with EFs. Our results show age-associated improvements in EFs and the cognitive variables assessed. Furthermore, correlation analyses reveal positive relationships between EFs and the other cognitive variables. More specifically, using structural equation modeling and including age direct and indirect effects, our results suggest that EFs explain to a greater extent performance on verbal and performance tasks. These findings provide further information to support research that considers preschool age to be a crucial period for the development of EFs and their relationship with other cognitive processes.

Examining Recall Memory in Infancy and Early Childhood Using the Elicited Imitation Paradigm

The ability to recall the past allows us to report on details of previous experiences, from the everyday to the significant. Because recall memory is commonly assessed using verbal report paradigms in adults, studying the development of this ability in preverbal infants and children proved challenging. Over the past 30 years, researchers have developed a non-verbal means of assessing recall memory known as the elicited or deferred imitation paradigm. In one variant of the procedure, participants are presented with novel three-dimensional stimuli for a brief baseline period before a researcher demonstrates a series of actions that culminate in an end- or goal-state. The participant is allowed to imitate the demonstrated actions immediately, after a delay, or both. Recall performance is then compared to baseline or to performance on novel control sequences presented at the same session; memory can be assessed for the individual target actions and the order in which they were completed. This procedure is an accepted analogue to the verbal report techniques used with adults, and it has served to establish a solid foundation of the nature of recall memory in infancy and early childhood. In addition, the elicited or deferred imitation procedure has been modified and adapted to answer questions relevant to other aspects of cognitive functioning. The broad utility and application of imitation paradigms is discussed, along with limitations of the approach and directions for future research.

Recall memory in children with Down syndrome and typically developing peers matched on developmental age

BACKGROUND

Whereas research has indicated that children with Down syndrome (DS) imitate demonstrated actions over short delays, it is presently unknown whether children with DS recall information over lengthy delays at levels comparable with typically developing (TD) children matched on developmental age.

METHOD

In the present research, 10 children with DS and 10 TD children participated in a two-session study to examine basic processes associated with hippocampus-dependent recall memory. At the first session, the researcher demonstrated how to complete a three-step action sequence with novel stimuli; immediate imitation was permitted as an index of encoding. At the second session, recall memory was assessed for previously modelled sequences; children were also presented with two novel three-step control sequences.

RESULTS

The results indicated that group differences were not apparent in the encoding of the events or the forgetting of information over time. Group differences were also not observed when considering the recall of individual target actions at the 1-month delay, although TD children produced more target actions overall at the second session relative to children with DS. Group differences were found when considering memory for temporal order information, such that TD children evidenced recall relative to novel control sequences, whereas children with DS did not.

CONCLUSIONS

These findings suggest that children with DS may have difficulty with mnemonic processes associated with consolidation/storage and/or retrieval processes relative to TD children.

Executive functions

Executive functions (EFs) make possible mentally playing with ideas; taking the time to think before acting; meeting novel, unanticipated challenges; resisting temptations; and staying focused. Core EFs are inhibition [response inhibition (self-control--resisting temptations and resisting acting impulsively) and interference control (selective attention and cognitive inhibition)], working memory, and cognitive flexibility (including creatively thinking "outside the box," seeing anything from different perspectives, and quickly and flexibly adapting to changed circumstances). The developmental progression and representative measures of each are discussed. Controversies are addressed (e.g., the relation between EFs and fluid intelligence, self-regulation, executive attention, and effortful control, and the relation between working memory and inhibition and attention). The importance of social, emotional, and physical health for cognitive health is discussed because stress, lack of sleep, loneliness, or lack of exercise each impair EFs. That EFs are trainable and can be improved with practice is addressed, including diverse methods tried thus far.