Sex and intelligence quotient differences in age of diagnosis among youth with attention-deficit hyperactivity disorder.

OBJECTIVES: Attention-deficit/hyperactivity disorder (ADHD) is the most common neurodevelopmental condition and is characterized by inattention, hyperactivity, and impulsivity. Research suggests that some populations, such as females and individuals with high intelligence quotients may be a risk for late ADHD diagnosis and subsequent treatment. Our goal is to advance our understanding of ADHD diagnosis, by examining (1) how child sex and cognitive abilities together are related to the age of diagnosis and (2) whether symptom presentation, current internalizing and externalizing symptoms, and demographic factors are related to age of diagnosis. METHODS: Our analyses contained children who completed the required tests (N = 568) from a pre-existing dataset of 1380 children with ADHD from the Province of Ontario Neurodevelopmental Disorders (POND) Network (pond-network.ca). First, we conducted a moderation analysis with sex as the predictor, cognitive abilities as the moderator, and age of diagnosis as the outcome. Second, we conducted correlation analyses examining how symptom presentation, current internalizing and externalizing symptoms, and demographic factors are related to age of diagnosis. RESULTS: Higher IQ was related to a later age of diagnosis. Higher hyperactive-impulsive symptoms and externalizing symptoms were related to an earlier age of diagnosis. Internalizing symptoms were trend associated with a later age of diagnosis in girls. Higher socioeconomic status and non-White maternal ethnicity were related to later age of diagnosis. CONCLUSIONS: IQ, sex, ADHD symptomology, internalizing symptoms, externalizing symptoms, and socio-demographic factors affect the age of diagnosis.

Examining the interaction between prenatal stress and polygenic risk for attention-deficit/hyperactivity disorder on brain growth in childhood: Findings from the DREAM BIG consortium.

This study explored the interactions among prenatal stress, child sex, and polygenic risk scores (PGS) for attention-deficit/hyperactivity disorder (ADHD) on structural developmental changes of brain regions implicated in ADHD. We used data from two population-based birth cohorts: Growing Up in Singapore Towards healthy Outcomes (GUSTO) from Singapore (n = 113) and Generation R from Rotterdam, the Netherlands (n = 433). Prenatal stress was assessed using questionnaires. We obtained latent constructs of prenatal adversity and prenatal mood problems using confirmatory factor analyses. The participants were genotyped using genome-wide single nucleotide polymorphism arrays, and ADHD PGSs were computed. Magnetic resonance imaging scans were acquired at 4.5 and 6 years (GUSTO), and at 10 and 14 years (Generation R). We estimated the age-related rate of change for brain outcomes related to ADHD and performed (1) prenatal stress by sex interaction models, (2) prenatal stress by ADHD PGS interaction models, and (3) 3-way interaction models, including prenatal stress, sex, and ADHD PGS. We observed an interaction between prenatal stress and ADHD PGS on mean cortical thickness annual rate of change in Generation R (i.e., in individuals with higher ADHD PGS, higher prenatal stress was associated with a lower rate of cortical thinning, whereas in individuals with lower ADHD PGS, higher prenatal stress was associated with a higher rate of cortical thinning). None of the other tested interactions were statistically significant. Higher prenatal stress may promote a slower brain developmental rate during adolescence in individuals with higher ADHD genetic vulnerability, whereas it may promote a faster brain developmental rate in individuals with lower ADHD genetic vulnerability.

No bilingual advantage in children's attentional disengagement: Congruency and sequential congruency effects in a large sample of monolingual and bilingual children.

According to recent accounts, bilingualism in childhood confers an advantage in a specific domain of executive functioning termed attentional disengagement. The current study tested this hypothesis in 492 children (245 boys; Mage = 10.98 years) from Canada, China, and Lebanon by testing for an association between language status and measures of attentional disengagement. Across the entire sample, monolinguals responded more quickly and accurately than bilinguals on a measure of attentional disengagement but differed in age, socioeconomic status, and general cognitive ability. Differences between monolinguals and bilinguals disappeared when the influence of these confounding variables was controlled using a matched samples analysis (ns = 105). Bayesian analyses further confirmed that the evidence was more likely under the null hypothesis than under the alternative hypothesis. In sum, there was little evidence of an association between language status and attentional disengagement in children.

The Bilingual Advantage in Children's Executive Functioning Is Not Related to Language Status: A Meta-Analytic Review.

There is considerable debate about whether bilingual children have an advantage in executive functioning relative to monolingual children. In the current meta-analysis, we addressed this debate by comprehensively reviewing the available evidence. We synthesized data from published studies and unpublished data sets, which equated to 1,194 effect sizes from 10,937 bilingual and 12,477 monolingual participants between the ages of 3 and 17 years. Bilingual language status had a small overall effect on children's executive functioning (g = .08, 95% confidence interval = [.01, .14]). However, the effect of language status on children's executive functioning was indistinguishable from zero (g = -.04) after we adjusted for publication bias. Further, no significant effects were apparent within the executive-attention domain, in which the effects of language status have been hypothesized to be most pronounced (g = .06, 95% confidence interval = [-.02, .14]). Taken together, available evidence suggests that the bilingual advantage in children's executive functioning is small, variable, and potentially not attributable to the effect of language status.

Disentangling language status and country-of-origin explanations of the bilingual advantage in preschoolers.

Bilingual preschoolers from East Asia outperform monolingual preschoolers from North America or Europe in executive functioning tasks, which has been interpreted as evidence of a bilingual advantage in executive functioning. This study tested whether these differences actually reflect country-of-origin effects given that East Asian preschoolers frequently outperform North American or European children in executive functioning tasks. Consistent with previous findings, Korean-English bilingual preschoolers made fewer errors in an age-appropriate executive functioning task than did English monolingual children in Canada. However, Korean-English bilingual preschoolers performed comparably to Korean monolingual preschoolers in Korea. Differences between Korean and Canadian children's executive functioning were not attributable to differences in parental cultural values or attitudes. The current findings suggest that differences between East Asian bilingual and North American monolingual preschoolers' executive functioning is related to differences in country of origin rather than language status.

Tracking the Brain's Functional Coupling Dynamics over Development.

The transition from childhood to adulthood is marked by pronounced functional and structural brain transformations that impact cognition and behavior. Here, we use a functional imaging approach to reveal dynamic changes in coupling strength between networks and the expression of discrete brain configurations over human development during rest and a cognitive control task. Although the brain's repertoire of functional states was generally preserved across ages, state-specific temporal features, such as the frequency of expression and the amount of time spent in select states, varied by age in ways that were dependent on condition. Increasing age was associated with greater variability of connection strengths across time at rest, while there was a selective inversion of this effect in higher-order networks during implementation of cognitive control. The results suggest that development is characterized by the modification of dynamic coupling to both maximize and constrain functional variability in response to ongoing cognitive and behavioral requirements.

Dynamic field theory and executive functions: lending explanation to current theories of development.

Buss and Spencer's monograph is an impressive achievement that is sure to have a lasting impact on the field of child development. The dynamic field theory (DFT) model that forms the heart of this contribution is ambitious in scope, detailed in its implementation, and rigorously tested against data, old and new. As such, the ideas contained in this fine document represent a qualitative advance in our understanding of young children's behavior, and lay a foundation for future research into the developmental origins of executive functioning.

Surprise and error: common neuronal architecture for the processing of errors and novelty.

According to recent accounts, the processing of errors and generally infrequent, surprising (novel) events share a common neuroanatomical substrate. Direct empirical evidence for this common processing network in humans is, however, scarce. To test this hypothesis, we administered a hybrid error-monitoring/novelty-oddball task in which the frequency of novel, surprising trials was dynamically matched to the frequency of errors. Using scalp electroencephalographic recordings and event-related functional magnetic resonance imaging (fMRI), we compared neural responses to errors with neural responses to novel events. In Experiment 1, independent component analysis of scalp ERP data revealed a common neural generator implicated in the generation of both the error-related negativity (ERN) and the novelty-related frontocentral N2. In Experiment 2, this pattern was confirmed by a conjunction analysis of event-related fMRI, which showed significantly elevated BOLD activity following both types of trials in the posterior medial frontal cortex, including the anterior midcingulate cortex (aMCC), the neuronal generator of the ERN. Together, these findings provide direct evidence of a common neural system underlying the processing of errors and novel events. This appears to be at odds with prominent theories of the ERN and aMCC. In particular, the reinforcement learning theory of the ERN may need to be modified because it may not suffice as a fully integrative model of aMCC function. Whenever course and outcome of an action violates expectancies (not necessarily related to reward), the aMCC seems to be engaged in evaluating the necessity of behavioral adaptation.

Activity-State Entropy: A novel brain entropy measure based on spatial patterns of activity.

BACKGROUND: Brain entropy is a measure of the complexity of brain activity that has been linked to various cognitive abilities. The measure is based on Shannon Entropy, a measure from Information Theory that quantifies the information capacity of a system from the probability distribution of its states. Most fMRI studies measure brain entropy at the voxel level as time-series entropy and assume that entropic time-series indicate complex large-scale spatiotemporal patterns of activity. NEW METHOD: We developed a novel measure of brain entropy called Activity-State Entropy. The method quantifies entropy based on underlying patterns of coactivation identified using Principal Components Analysis. These patterns, termed eigenactivity states, combine in time-varying proportions. RESULTS: We showed that Activity-State Entropy is sensitive to the complexity of the spatiotemporal patterns of activity in simulated fMRI data. We then applied this measure to real resting-state fMRI data and found that the eigenactivity states that explained the most variance in the data were comprised of large clusters of coactivating voxels, including clusters within Default Mode Network regions. More entropic brains were increasingly influenced by eigenactivity states comprised of smaller and more sparsely distributed clusters. COMPARISON TO EXISTING METHODS: We compared Activity-State Entropy to Sample Entropy and Dispersion Entropy, two time-series entropy measures commonly used in neuroimaging research, and found all three measures were positively correlated. CONCLUSIONS: Activity-State Entropy provides a measure of the spatiotemporal complexity of brain activity that complements time-series based measures of brain entropy.

Culture, executive functions, and academic achievement.

Although it is well known that children of East Asian immigrants show higher academic achievement than native-born North American children, the social-cognitive determinants of this difference remain poorly understood. Given the importance of executive functions (EF) for academic achievement, and evidence that EF develops more quickly in East Asian compared to North American cultures, it is conceivable that differences in academic achievement might be rooted in EF differences between these groups. We examine this possibility by reviewing evidence of cross-cultural differences in EF development but find core concepts and findings limited in several key respects. To address these limitations, we propose a framework for relating EF, culture, and academic achievement that draws on new theoretical ideas about the nature of EF and its relation to social context. We conclude by discussing avenues for future research on the relations between culture, executive functions, and academic achievement.

TAG-ME again: A serious game for measuring working memory.

BrainTagger (demo version: researcher-demo.braintagger.com) is a suite of Target Acquisition Games for Measurement and Evaluation (TAG-ME). Here we introduce TAG-ME Again, a serious game modeled after the well-established N-Back task, to assess working memory ability across three difficulty levels corresponding to 1-, 2-, and 3-back conditions. We also report on two experiments aimed at assessing convergent validity with the N-Back task. Experiment 1 examined correlations with N-Back task performance in a sample of adults (n = 31, 18-54 years old) across three measures: reaction time; accuracy; a combined RT/accuracy metric. Significant correlations between game and task were found, with the strongest relationship being for the most difficult version of the task (3-Back). In Experiment 2 (n = 66 university students, 18-22 years old), we minimized differences between the task and the game by equating stimulus-response mappings and spatial processing demands. Significant correlations were found between game and task for both the 2-Back and 3-Back levels. We conclude that TAG-ME Again is a gamified task that has convergent validity with the N-Back Task.

Adverse Life Experiences and Brain Function: A Meta-Analysis of Functional Magnetic Resonance Imaging Findings.

Importance: Adverse life experiences have been proposed to contribute to diverse mental health problems through an association with corticolimbic functioning. Despite compelling evidence from animal models, findings from studies in humans have been mixed; activation likelihood estimation (ALE) meta-analyses have failed to identify a consistent association of adverse events with brain function. Objective: To investigate the association of adversity exposure with altered brain reactivity using multilevel kernel density analyses (MKDA), a meta-analytic approach considered more robust than ALE to small sample sizes and methodological differences between studies. Data Sources: Searches were conducted using PsycInfo, Medline, EMBASE, and Web of Science from inception through May 4, 2022. The following search term combinations were used for each database: trauma, posttraumatic stress disorder (PTSD), abuse, maltreatment, poverty, adversity, or stress; and functional magnetic resonance imaging (fMRI) or neuroimaging; and emotion, emotion regulation, memory, memory processing, inhibitory control, executive functioning, reward, or reward processing. Study Selection: Task-based fMRI studies within 4 domains (emotion processing, memory processing, inhibitory control, and reward processing) that included a measure of adverse life experiences and whole-brain coordinate results reported in Talairach or Montreal Neurological Institute space were included. Conference abstracts, books, reviews, meta-analyses, opinions, animal studies, articles not in English, and studies with fewer than 5 participants were excluded. Data Extraction and Synthesis: Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses reporting guideline, 2 independent reviewers assessed abstracts and full-text articles for entry criteria. A third reviewer resolved conflicts and errors in data extraction. Data were pooled using a random-effects model and data analysis occurred from August to November 2022. Main Outcomes and Measures: Peak activation x-axis (left-right), y-axis (posterior-anterior), and z-axis (inferior-superior) coordinates were extracted from all studies and submitted to MKDA meta-analyses. Results: A total of 83 fMRI studies were included in the meta-analysis, yielding a combined sample of 5242 participants and 801 coordinates. Adversity exposure was associated with higher amygdala reactivity (familywise error rate corrected at P < .001; x-axis = 22; y-axis = -4; z-axis = -17) and lower prefrontal cortical reactivity (familywise error rate corrected at P < .001; x-axis = 10; y-axis = 60; z-axis = 10) across a range of task domains. These altered responses were only observed in studies that used adult participants and were clearest among those who had been exposed to severe threat and trauma. Conclusions and Relevance: In this meta-analysis of fMRI studies of adversity exposure and brain function, prior adversity exposure was associated with altered adult brain reactivity to diverse challenges. These results might better identify how adversity diminishes the ability to cope with later stressors and produces enduring susceptibility to mental health problems.

Brain regions associated with moment-to-moment adjustments in control and stable task-set maintenance.

While there is some consensus that cognitive control involves both a capacity to rapidly adjust to unexpected challenges and a capacity to prospectively maintain task-sets over longer timescales, there is disagreement concerning the neural implementation of these capacities. Some accounts, for example, associate rapid adjustments in control with a network of lateral prefrontal and parietal cortices and task-set maintenance with a network of anterior cingulate and insular cortices. Other accounts propose almost the opposite associations. The present study compared these accounts by means of a hybrid fMRI design. Twenty-three right-handed adults were administered a conflict-adaptation paradigm in which the frequency of compatible trials, and therefore, demands on rapid adjustments and stable task-set maintenance, varied parametrically across conditions. Increased demands on moment-to-moment adjustments were associated with a profile of phasic activity in anterior cingulate cortex, anterior insula, and inferior parietal cortex. By contrast, increased demands on stable task-set maintenance were associated with increased sustained activity in medial superior frontal gyrus. Theoretical implications are discussed.

Developmental changes in patterns of brain activity associated with moment-to-moment adjustments in control.

The current study investigated age-related changes in patterns of brain activity associated with moment-to-moment adjustments in control through the use of fMRI. Fifty-eight participants ranging continuously in age from 9 to 32 years were scanned as they performed a task in which the need for rapid adjustments in control was greater in one condition than another. Despite comparable behavioral performance across ages, moment-to-moment adjustments were associated with stronger engagement of anterior cingulate, anterior insula, lateral prefrontal cortex and the intraparietal sulcus in older than in younger participants. The findings confirm the importance of cingulo-insular and fronto-parietal cortices for moment-to-moment adjustments in control, and suggest continuous increases in the utilization of these networks over development.

Perseveration and the status of 3-year-olds' knowledge in a card-sorting task: evidence from studies involving congruent flankers.

Infants and young children often perseverate despite apparent knowledge of the correct response. Two Experiments addressed questions concerning the status of such knowledge in the context of a card-sorting task. In Experiment 1, three groups of 3-year-olds sorted bivalent cards one way and then were instructed to switch and sort the same cards using new rules under varying conditions of support offered by congruent flankers. Although formal aspects of the task such as higher-order rule use, stimulus redescription, and dimensional shifting remained constant across all conditions, use of the new rules increased with parametric increases in environmental support for the use of the new rules. In Experiment 2, 3-year-olds were more likely to switch and use new rules when test stimuli were flanked by congruent flankers rather than neutral flankers, even though both conditions made equivalent demands on attentional inhibition. Thus, in both experiments, children's knowledge of the new rules proved to be adequate under less demanding conditions but inadequate under more demanding conditions. These findings are consistent with the idea that children's knowledge is graded in strength rather than present or absent.

Both task-irrelevant and task-relevant information trigger reactive conflict adaptation in the item-specific proportion-congruent paradigm.

Adapting attention flexibly is a fundamental ability of the human control system. In the color-word Stroop task, for example, congruency effects are typically smaller for colors and words that appear mainly in incongruent stimuli (mostly-incongruent items) than for colors and words that appear mainly in congruent stimuli (mostly-congruent items). At least part of this item-specific proportion-congruent (ISPC) effect is due to a process of reactive conflict adaptation that affords higher selectivity (i.e., more efficient selection of task-relevant information) when a specific stimulus is presented that is frequently associated in the experiment with conflicting task-irrelevant information. What is unclear, however, is whether, normally, this stimulus-specific adaptation is triggered by the task-relevant component, the task-irrelevant component, or both components of the stimulus. In two experiments, using modified color-word (Experiment 1) and spatial (Experiment 2) Stroop tasks that allowed task-relevant and task-irrelevant triggering processes to be dissociated, we found that the two processes have approximately equivalent impacts. Because these results were obtained in experiments imposing no limitations on the processes potentially contributing to the ISPC effect, these results challenge claims that the ISPC effect involves conflict-adaptation processes only in special situations. The ISPC effect may involve conflict-adaptation processes in most situations, with both task-relevant and task-irrelevant information triggering such processes.

Bilingualism and executive attention: Evidence from studies of proactive and reactive control.

According to some accounts, the bilingual advantage is most pronounced in the domain of executive attention rather than inhibition and should therefore be more easily detected in conflict adaptation paradigms than in simple interference paradigms. We tested this idea using two conflict adaptation paradigms, one that elicits a list-wide proportion-congruent effect and one that elicits an item-specific proportion-congruent effect. In both cases, the relevant finding is that congruency effects are reduced when the proportion of congruent to incongruent items is smaller. These effects are validated measures of proactive and reactive control, respectively, and are aspects of executive attention known to be associated with individual differences in working memory capacity. We reasoned that if bilingualism affects executive attention in a similar way as does working memory capacity, indices of proactive and reactive control should be comparably associated with continuous variation in language status and working memory capacity. In two experiments, we replicated previous findings that working memory capacity is associated with variation in congruency effects (suggesting greater reliance on proactive control). In contrast, language status had no consistent association with performance, save for a hint that bilingualism may be associated with greater reliance on reactive control. Thus, the bilingual advantage may exist, but not in proactive control or any other aspects of executive attention that have been proposed thus far. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Brain Network Connectivity and Executive Function in Children with Infantile Hydrocephalus.

Introduction: Infantile hydrocephalus (HCP) is a condition in which there is an abnormal buildup of cerebrospinal fluid in the ventricles within the first few months of life, which puts pressure on surrounding brain tissues. Compression of the developing brain increases the risk of secondary brain injury and cognitive disabilities. Methods: In this study, we used diffusion-weighted imaging and resting-state functional magnetic resonance imaging to investigate the effects of ventricle dilatation on structural and functional brain networks in children with shunted infantile HCP and examined how these brain changes may impact executive function. Results: We found that children with HCP have altered structural and functional connectivity between and within large-scale networks. Moreover, hyperconnectivity between the ventral attention and default mode network in children with HCP correlated with reduced executive function scores. Compared with typically developing age-matched control participants, our patient population also had lower fractional anisotropy in posterior white matter. Discussion: Overall, these findings suggest that infantile HCP has long-term effects on brain network connectivity, white matter development, and executive function in children at school age. Future work will examine the relationship between ventricular volumes before shunt placement in infancy and brain network development throughout childhood.

Multiple processes underlying dimensional change card sort performance: a developmental electrophysiological investigation.

Cognitive flexibility follows a protracted developmental trajectory [Morton, J. B. Understanding genetic, neurophysiological, and experiential influences on the development of executive functioning: The need for developmental models. Wiley Interdisciplinary Reviews: Cognitive Science, 2010]. For example, performance and patterns of brain activity associated with the dimensional change card sort (DCCS) show continued age-related changes into early adolescence. According to many theoretical accounts, the DCCS places demands on a single underlying executive process. In the present study, we investigated the possibility that multiple processes unfold within the timeframe of a single DCCS trial through the use of ERPs. Children (n = 40), adolescents (n = 20), and adults (n = 20) performed a modified version of the DCCS with distinct instruction cue- and stimulus-related periods. On any particular trial, the sorting rule either changed (i.e., switch trials) or remained the same (i.e., repeat trials), and the imperative stimulus either embodied conflict (i.e., bivalent stimuli) or did not (i.e., univalent stimuli). Findings were consistent with the hypothesis that multiple distinct executive processes unfold within a single trial. First, for all age groups, rule switching and conflict processing made additive contributions to variability in RT. Second, ERPs time-locked to the instruction cue revealed a late frontal negativity whose amplitude was greater for switch trials relative to repeat trials and that was associated with the magnitude of the behavioral switch cost, whereas ERPs time-locked to the imperative stimulus revealed a fronto-central N2 whose amplitude was greater for bivalent than univalent stimuli and that was associated with the magnitude of the behavioral conflict cost. Finally, switch and conflict-related processes showed distinct developmental trajectories. Taken together, the findings suggest that multiple executive processes underlie DCCS performance and its development. Theoretical implications are discussed.

The development of future-oriented control: an electrophysiological investigation.

Cognitive control, or the ability to focus attention and select task-appropriate responses, is not static but can be dynamically adjusted in the face of changing environmental circumstances. Several models suggest a role for conflict-monitoring in triggering these adjustments, whereby instances of response uncertainty are detected by the anterior cingulate cortex and strengthen attention-guiding rules actively maintained by lateral prefrontal cortex. Given the continued development of active maintenance mechanisms into adolescence, these models predict that the capacity to dynamically modulate control should be protracted in its development. The present study tested this prediction by examining age-related differences in behavioral and electrophysiological adaptations to prior conflict. Children, adolescents, and adults were administered the Dimensional Change Card Sort (DCCS; Zelazo, 2006) - a developmentally-appropriate task modified so that response conflict varied from trial to trial - as cortical activity was measured by means of event-related potentials (ERPs). Although all groups showed a robust conflict effect, there were pronounced age-related differences in behavioral and electrophysiological adaptations to prior conflict. First, responses to incongruent trials were faster following incongruent trials than following congruent trials, but only for adults and adolescents. Second, ERP components that indexed response conflict, and the cortical source of these components, were modulated by preceding conflict for adults and adolescents, but not children. Taken together, the findings suggest that adults and adolescents take advantage of prior conflict to prepare for the future, whereas children respond to cognitive challenges as they occur. Theoretical implications are discussed.