Preschool Inhibitory Control Predicts ADHD Group Status and Inhibitory Weakness in School

Profiles of executive functions in middle childhood and prediction of later self-regulation

Most research on the development of executive functions (EF) has applied variable-oriented approaches, neglecting the potential inter- and intraindividual interplay of these capacities. In a person-oriented approach, the present study identified varying profiles of performance for three cool EF facets: inhibition, working-memory updating, and cognitive flexibility, as well as two hot EF facets: affective decision-making and delay of gratification, in a community sample of 1,657 children (T1; age: 6-11 years, M = 8.36 years, 52.1% female) via latent profile analysis. The best-fitting model allowed for partial dependence across the three cool EF and included four profiles: all-average (69.4% of the children), low-delay (19.0%), regulated-decision-making (7.0%), and low-inhibition (4.6%). Age, binary sex, socio-economic status, multilingualism, and processing speed were identified as significant characteristics of EF profile membership. Longitudinally, a higher probability of belonging to the low-inhibition profile predicted lower rates of the self-regulatory outcome of inhibitory control 1 year later, while belonging to the regulated-decision-making profile predicted lower rates of the ability to plan and organize 3 years later. These results not only demonstrate the existence of subgroups with different concurrent within-person expressions of EF performance, but also identify related characteristics and longitudinal outcomes of subgroup membership. In turn, these conclusions stress the importance of person-oriented research to inform on differing weaknesses or strengths in EF performance for varying individuals, thereby providing valuable insight for educational and clinical research into the design of effective personalized support or interventions during middle childhood.

Research Review: A systematic review and meta-analysis of infant and toddler temperament as predictors of childhood attention-deficit/hyperactivity disorder

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder with onset as early as preschool and impairment across the lifespan. Temperament factors, specifically those that theoretically map onto ADHD symptoms, may be early markers of risk for developing later childhood ADHD that could be identifiable in infancy or toddlerhood. This meta-analysis examined the associations between these early temperamental factors and later symptoms and diagnosis of ADHD and mapped early temperament constructs onto the three ADHD symptom dimensions.

METHODS

A systemic review of the literature was conducted to identify prospective longitudinal studies that included theoretically relevant temperament constructs (sustained attention, activity level, inhibition, and negative emotionality) examined from birth to 36 months old and ADHD (symptoms or diagnosis) in preschool or childhood. The association between each temperament construct and ADHD outcomes was examined using pooled standardized estimates in meta-analyses.

RESULTS

Forty-eight articles (n = 112,716 infants/toddlers) prospectively examined temperament and the relation to childhood ADHD symptoms or diagnosis. Activity level (k = 18) in infancy and toddlerhood was moderately associated with childhood ADHD (r = .39, CI = 0.27, 0.51, p < .001). Moderate effect sizes were also observed for sustained attention (k = 9; r = -.28, CI = -0.42, -0.12, p < .001) and negative emotionality (k = 33; r = .25, CI = 0.16, 0.34, p < .001) with ADHD. The specificity of each temperament construct for later ADHD symptom dimensions was such that activity level and negative emotionality were predictive of all three symptom dimensions (i.e., inattention, hyperactivity/impulsivity, and combined), whereas sustained attention was only associated with combined symptoms.

CONCLUSIONS

Infant and toddler temperament is an early risk factor for the development of childhood ADHD that could be utilized for early intervention identification. Yet, this systematic review found that relatively few prospective longitudinal studies have examined sustained attention (k = 9) and inhibition (k = 15) in infancy and toddlerhood in relation to later ADHD highlighting the need for further research.

Changes in executive function in pediatric brain tumor survivors

OBJECTIVE

Pediatric oncology survivors are at risk for executive function (EF) and working memory (WM) deficits, which can be measured via performance-based measures or rating scales. Previous studies have shown these measurement methods to be weakly correlated. This study aimed to describe parent-rated EF and performance-based WM (PBWM) in pediatric brain tumor (BT) survivors, examine change in EF and PBWM across time, and investigate the relationship between parent-rated WM and PBWM.

METHOD

The sample included 56 patients diagnosed with a BT in childhood (M_age  = 6.94 years; SD = 4.05) seen twice for clinical neuropsychological evaluation. PBWM was examined via the auditory WM scale from a Wechsler intelligence measure or Differential Ability Scales-II. Parents completed the Behavior Rating Inventory of Executive Function (BRIEF)/BRIEF-P/BRIEF-2 as a measure of global EF (Global Executive Composite [GEC]), metacognitive skills (Metacognitive Index/Cognitive Regulation Index [MI/CRI]), behavioral regulation (Behavior Regulation Index [BRI]), and emotional regulation (Emotion Regulation Index [ERI]).

RESULTS

GEC, MI/CRI, and ERI at Time 1 were significantly above the mean (p < .01); BRI and PBWM did not differ from the normative mean. All measures were significantly higher than the normative mean at Time 2 (p < .05). PBWM was both clinically and statistically elevated (p < .001). There was a significant change across time in PBWM (p < .05), but not GEC, MI/CRI, ERI, or BRI. PBWM was weakly correlated with the BRIEF WM subscale at Time 1 and Time 2 (all p > .05).

CONCLUSIONS

Multiple measures of EF should be considered when providing diagnoses and recommendations for pediatric BT survivors. Furthermore, given declines across time, findings document need for continued monitoring and reassessment of survivors as they get further out from treatment.

Systematic Review and Meta-analysis: The Science of Early-Life Precursors and Interventions for Attention-Deficit/Hyperactivity Disorder

OBJECTIVE

To evaluate which early neurocognitive and behavioral precursors are associated with the development of attention-deficit/hyperactivity disorder (ADHD) and whether these are currently targeted in early interventions.

METHOD

We conducted 2 systematic reviews and meta-analyses of empirical studies to examine the following: (1) early-life (0-5 years) neurocognitive and behavioral precursors associated with familial likelihood for ADHD, an early ADHD diagnosis/elevated ADHD symptoms, and/or the presence of later-childhood ADHD; and (2) interventions delivered to children aged 0 to 5 years targeting the identified precursors or measuring these as outcomes. Standardized mean differences (Hedges' g) and pre-post-treatment change scores (SMD) were computed.

RESULTS

A total of 149 studies (165,095 participants) investigating 8 neurocognitive and behavioral domains met inclusion criteria for part 1. Multi-level random-effects meta-analyses on 136 studies revealed significant associations between ADHD and poorer cognitive (g = -0.46 [95% CIs: -0.59, -0.33]), motor (g = -0.35 [CIs: -0.48, -0.21]) and language (g = -0.43 [CIs: -0.66, -0.19]) development, social (g = 0.23 [CIs: 0.03, 0.43]) and emotional (g = 0.46 [CIs: 0.33, 0.58]) difficulties, early regulatory (g = 0.30 [CIs: 0.18, 0.43]) and sleep (g = 0.29 [CIs: 0.14, 0.44]) problems, sensory atypicalities (g = 0.52 [CIs: 0.16, 0.88]), elevated activity levels (g = 0.54 [CIs: 0.37, 0.72]), and executive function difficulties (g = 0.34 [CIs: 0.05, 0.64] to -0.87 [CIs: -1.35, -0.40]). A total of 32 trials (28 randomized, 4 nonrandomized, 3,848 participants) testing early interventions that targeted the identified precursors met inclusion criteria for part 2. Multi-level random-effects meta-analyses on 22 studies revealed significant intervention-related improvements in ADHD symptoms (SMD = 0.43 [CIs: 0.22, 0.64]) and working memory (SMD = 0.37 [CIs: 0.06, 0.69]).

CONCLUSION

Children aged 0 to 5 years with current or later-emerging ADHD are likely to experience difficulties in multiple neurocognitive/behavioral functions. Early interventions show some effectiveness in reducing ADHD symptoms, but their effects on neurocognitive/behavioral difficulties require further study.

To snack or not to snack: Using fNIRS to link inhibitory control to functional connectivity in the toddler brain

Inhibitory control (IC) emerges in infancy (Holmboe, Bonneville-Roussy, Csibra, & Johnson, 2018), continues to develop throughout childhood (Lui, Zhu, Zeigler, & Shi, 2015; Ordaz, Foran, Velanova, & Luna, 2013) and is linked to later life outcomes such as school achievement, prosocial behavior, and psychopathology (Duckworth, Tsukayama, & Kirby, 2013; Jaekel, Madzwamuse, & Wolke, 2015). Little, however, is known about the neural processes underpinning IC, especially in 2-year-olds. In this study, we examine functional connectivity in 2.5-year-olds while recording hemodynamic responses via functional infrared spectroscopy (fNIRS) during a traditional snack delay task. We found that functional connectivity strength between left frontal and parietal cortex and bilateral parietal cortex were positively associated with performance on this task. The current findings present the first neural data for toddlers during this inhibitory control task. Further, these data are the first to link this self-regulatory process to differences in brain development within this population. Implications for future directions and work with clinical populations are discussed. This article is protected by copyright. All rights reserved.