How Does Parental Monitoring Reduce Adolescent Substance Use? Preliminary Tests of Two Potential Mechanisms

OBJECTIVE

The purpose of this study was to test two non-exclusive mechanisms by which parental monitoring might reduce teen substance use. The first mechanism (M1) is that monitoring increases punishment for substance use since parents who monitor more are more likely to find out when substance use occurs. The second mechanism (M2) is that monitoring directly prevents/averts teens from using substances in the first place for fear that parents would find out.

METHOD

A total of 4,503 teens ages 11-15 years old in 21 communities across the United States completed a survey reporting on parents' monitoring/knowledge and teens' substance use.

RESULTS

We found no support for M1: Parents with greater parental monitoring were not more likely to be aware when the teen had used substances (odds ratios = 0.79-0.93, ps = .34-.85), so they could not have increased the rate of punishment. We found support for M2: When asked directly, teens identified instances in which they planned to or had a chance to use substances but did not because their parents got in the way or would have found out (p < .01). Had all those opportunities for substance use occurred rather than been averted by parents, the prevalence of substance use in the sample would have been 1.4 times higher.

CONCLUSIONS

In this community-based sample of teens, we failed to support prior punishment-centric theories of how monitoring might reduce teen substance use. Rather, monitoring may directly discourage teens from using substances regardless of whether it increases parents' awareness of substance use or results in more punishment. Replication in other samples and contexts is needed.

Direct and indirect effects of mother's spatial ability on child's spatial ability: What role does the home environment play?

Individual differences in spatial thinking are predictive of children's math and science achievement and later entry into Science, Technology, Engineering, and Mathematics (STEM) disciplines. Little is known about whether parent characteristics predict individual differences in children's spatial thinking. This study aims to understand whether, and to what extent, mother's intrinsic (i.e., mental rotation) and extrinsic (i.e., spatial scaling) spatial ability directly and indirectly, via the variation in home spatial environment, predicts children's intrinsic and extrinsic spatial ability. A total of 165 mothers and their 4-6-year-old children were recruited to participate in a remote video session with an experimenter. Mothers were administered a forced-choice Intrinsic Spatial Toy Preference Task gauging their preference for highly spatial versus less spatial toys and asked questions with the Home Intrinsic Spatial Environmental Questionnaire about the frequency with which they engage their child in spatial activities at home. Mothers completed a Mental Rotations Test and a Spatial Scaling Task adapted for adults. Children were administered the Picture Rotation Task, the Spatial Scaling Task, and the Peabody Picture Vocabulary Test. Structural equation modeling was used to examine direct and indirect, via home spatial environment and toy choices, influences of mother spatial ability on child spatial ability. Contrary to our predictions, we did not find direct, nor indirect, relations between mother and child spatial ability. These findings suggest that researchers should consider alternative conceptualizations of the early home spatial environment beyond the frequency of spatial play in the home. RESEARCH HIGHLIGHTS: The identification of factors that predict individual differences in children's spatial ability is important in order to maximize STEM learning outcomes. Data collection was conducted remotely rather than in traditional preschool or laboratory settings. Contrary to our pre-registered hypotheses, no significant relations between mother spatial ability, the early home spatial environment, and children's development of spatial skills were found. Future research should consider examining the amount of spatial language used in the home or the quality of parent-child interactions during spatial play as potential explanations for individual differences in children's spatial ability.

Neurite density of the hippocampus is associated with trace eyeblink conditioning latency in 4- to 6-year-olds

Limited options exist to evaluate the development of hippocampal function in young children. Research has established that trace eyeblink conditioning (EBC) relies on a functional hippocampus. Hence, we set out to investigate whether trace EBC is linked to hippocampal structure, potentially serving as a valuable indicator of hippocampal development. Our study explored potential associations between individual differences in hippocampal volume and neurite density with trace EBC performance in young children. We used onset latency of conditioned responses (CR) and percentage of conditioned responses (% CR) as measures of hippocampal-dependent associative learning. Using a sample of typically developing children aged 4 to 6 years (N = 30; 14 girls; M = 5.70 years), participants underwent T1- and diffusion-weighted MRI scans and completed a 15-min trace eyeblink conditioning task conducted outside the MRI. % CR and CR onset latency were calculated based on all trials involving tone-puff presentations and tone-alone trials. Findings revealed a connection between greater left hippocampal neurite density and delayed CR onset latency. Children with higher neurite density in the left hippocampus tended to blink closer to the onset of the unconditioned stimulus, indicating that structural variations in the hippocampus were associated with more precise timing of conditioned responses. No other relationships were observed between hippocampal volume, cerebellum volume or neurite density, hippocampal white matter connectivity and any EBC measures. Preliminary results suggest that trace EBC may serve as a straightforward yet innovative approach for studying hippocampal development in young children and populations with atypical development.

Reduced recruitment of inhibitory control regions in very young children with ADHD during a modified Kiddie Continuous Performance Task: a fMRI study

Attention-Deficit/Hyperactivity Disorder (ADHD) symptom profiles are known to undergo changes throughout development, rendering the neurobiological assessment of ADHD challenging across different developmental stages. Particularly in young children (ages 4 to 7 years), measuring inhibitory control network activity in the brain has been a formidable task due to the lack of child-friendly functional Magnetic Resonance Imaging (fMRI) paradigms. This study aims to address these difficulties by focusing on measuring inhibitory control in very young children within the MRI environment. A total of 56 children diagnosed with ADHD and 78 typically developing (TD) 4-7-year-old children were examined using a modified version of the Kiddie-Continuous Performance Test (K-CPT) during BOLD fMRI to assess inhibitory control. We concurrently evaluated their performance on the established and standardized K-CPT outside the MRI scanner. Our findings suggest that the modified K-CPT effectively elicited robust and expected brain activity related to inhibitory control in both groups. Comparisons between the two groups revealed subtle differences in brain activity, primarily observed in regions associated with inhibitory control, such as the inferior frontal gyrus, anterior insula, dorsal striatum, medial pre-supplementary motor area (pre-SMA), and cingulate cortex. Notably, increased activity in the right anterior insula was associated with improved response time (RT) and reduced RT variability on the K-CPT administered outside the MRI environment, although this did not survive statistical correction for multiple comparisons. In conclusion, our study successfully overcame the challenges of measuring inhibitory control in very young children within the MRI environment by utilizing a modified K-CPT during BOLD fMRI. These findings shed light on the neurobiological correlates of inhibitory control in ADHD and TD children, provide valuable insights for understanding ADHD across development, and potentially inform ADHD diagnosis and intervention strategies. The research also highlights remaining challenges with task fMRI in very young clinical samples.

Parental knowledge/monitoring and adolescent substance use: A causal relationship?

OBJECTIVE

Many studies have shown that parental knowledge/monitoring is correlated with adolescent substance use, but the association may be confounded by the many preexisting differences between families with low versus high monitoring. We attempted to produce more rigorous evidence for a causal relation using a longitudinal design that took advantage of within-family fluctuations in knowledge/monitoring during the COVID-19 pandemic.

METHOD

Youth (N = 8,780, age range = 10.5-15.6 years) at 21 sites across the United States completed up to seven surveys over 12 months. Youth reported on their parents' knowledge/monitoring of their activities and their substance use in the past month. Regressions were fit to within-family changes in youth-perceived knowledge/monitoring and substance use between survey waves. By analyzing within-family changes over time, we controlled for all stable, a priori differences that exist between families with low versus high levels of youth-perceived knowledge/monitoring.

RESULTS

Youth initially denying substance use were significantly more likely to start reporting use when they experienced a decrease in the level of perceived knowledge/monitoring (relative risk [RR] = 1.18, p < .001). Youth initially endorsing substance use were significantly more likely to stop reporting use when they experienced an increase in the level of perceived knowledge/monitoring (RR = 1.06; p < .001). Associations were similar or larger when adjusting for several time-varying potential confounders.

CONCLUSION

In a large, sociodemographically diverse sample, within-family changes in youth-perceived parental knowledge/monitoring over time were robustly associated with changes in youths' engagement in substance use. Findings lend support to the hypothesis that parent knowledge/monitoring is causally related to substance involvement in early adolescence. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Effects of the COVID-19 pandemic on screen time and sleep in early adolescents

OBJECTIVE

During the COVID-19 pandemic, adolescents and families have turned to online activities and social platforms more than ever to maintain well-being, connect remotely with friends and family, and online schooling. However, excessive screen use can have negative effects on health (e.g., sleep). This study examined changes in sleep habits and recreational screen time (social media, video gaming), and their relationship, before and across the first year of the pandemic in adolescents in the Adolescent Brain Cognitive Development (ABCD) Study.

METHOD

Mixed-effect models were used to examine associations between self-reported sleep and screen time using longitudinal data of 5,027 adolescents in the ABCD Study, assessed before the pandemic (10-13 years) and across six time points between May 2020 and March 2021 (pandemic).

RESULTS

Time in bed varied, being higher during May-August 2020 relative to pre-pandemic, partially related to the school summer break, before declining in October 2020 to levels lower than pre-pandemic. Screen time steeply increased and remained high across all pandemic time points relative to pre-pandemic. Higher social media use and video gaming were associated with shorter time in bed, later bedtimes, and longer sleep onset latency.

CONCLUSIONS

Sleep behavior and screen time changed during the pandemic in early adolescents. More screen time was associated with poorer sleep behavior, before and during the pandemic. While recreational screen usage is an integral component of adolescent's activities, especially during the pandemic, excessive use can have negative effects on essential health behaviors, highlighting the need to promote balanced screen usage. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Family Well-Being During the COVID-19 Pandemic: The Risks of Financial Insecurity and Coping

During the COVID-19 pandemic, families have experienced unprecedented financial and social disruptions. We studied the impact of preexisting psychosocial factors and pandemic-related financial and social disruptions in relation to family well-being among N = 4091 adolescents and parents during early summer 2020, participating in the Adolescent Brain Cognitive DevelopmentSM Study. Poorer family well-being was linked to prepandemic psychosocial and financial adversity and was associated with pandemic-related material hardship and social disruptions to routines. Parental alcohol use increased risk for worsening of family relationships, while a greater endorsement of coping strategies was mainly associated with overall better family well-being. Financial and mental health support may be critical for family well-being during and after a widespread crisis, such as the COVID-19 pandemic.

Structural and diffusion-weighted brain imaging predictors of attention-deficit/hyperactivity disorder and its symptomology in very young (4- to 7-year-old) children

The current study aimed to identify the key neurobiology of attention-deficit/hyperactivity disorder (ADHD), as it relates to ADHD diagnostic category and symptoms of hyperactive/impulsive behaviour and inattention. To do so, we adapted a predictive modelling approach to identify the key structural and diffusion-weighted brain imaging measures and their relative standing with respect to teacher ratings of executive function (EF) (measured by the Metacognition Index of the Behavior Rating Inventory of Executive Function [BRIEF]) and negativity and emotion regulation (ER) (measured by the Emotion Regulation Checklist [ERC]), in a critical young age range (ages 4 to 7, mean age 5.52 years, 82.2% Hispanic/Latino), where initial contact with educators and clinicians typically take place. Teacher ratings of EF and ER were predictive of both ADHD diagnostic category and symptoms of hyperactive/impulsive behaviour and inattention. Among the neural measures evaluated, the current study identified the critical importance of the largely understudied diffusion-weighted imaging measures for the underlying neurobiology of ADHD and its associated symptomology. Specifically, our analyses implicated the inferior frontal gyrus as a critical predictor of ADHD diagnostic category and its associated symptomology, above and beyond teacher ratings of EF and ER. Collectively, the current set of findings have implications for theories of ADHD, the relative utility of neurobiological measures with respect to teacher ratings of EF and ER, and the developmental trajectory of its underlying neurobiology.

Volumetric development of hippocampal subfields and hippocampal white matter connectivity: Relationship with episodic memory

The hippocampus is a complex structure composed of distinct subfields. It has been central to understanding neural foundations of episodic memory. In the current cross-sectional study, using a large sample of 830, 3- to 21-year-olds from a unique, publicly available dataset we examined the following questions: (1) Is there elevated grey matter volume of the hippocampus and subfields in late compared to early development? (2) How does hippocampal volume compare with the rest of the cerebral cortex at different developmental stages? and (3) What is the relation between hippocampal volume and connectivity with episodic memory performance? We found hippocampal subfield volumes exhibited a nonlinear relation with age and showed a lag in volumetric change with age when compared to adjacent cortical regions (e.g., entorhinal cortex). We also observed a significant reduction in cortical volume across older cohorts, while hippocampal volume showed the opposite pattern. In addition to age-related differences in gray matter volume, dentate gyrus/cornu ammonis 3 volume was significantly related to episodic memory. We did not, however, find any associations with episodic memory performance and connectivity through the uncinate fasciculus, fornix, or cingulum. The results are discussed in the context of current research and theories of hippocampal development and its relation to episodic memory.

Parental Knowledge/Monitoring and Depressive Symptoms During Adolescence: Protective Factor or Spurious Association?

Parental knowledge/monitoring is negatively associated with adolescents' depressive symptoms, suggesting monitoring could be a target for prevention and treatment. However, no study has rigorously addressed the possibility that this association is spurious, leaving the clinical and etiological implications unclear. The goal of this study was to conduct a more rigorous test of whether knowledge/monitoring is causally related to depressive symptoms. 7940 youth (ages 10.5-15.6 years, 49% female) at 21 sites across the U.S. completed measures of parental knowledge/monitoring and their own depressive symptoms at four waves 11-22 weeks apart during the COVID-19 pandemic. First, monitoring and depression were examined in standard, between-family regression models. Second, within-family changes in monitoring and depression between assessments were examined in first differenced regressions. Because the latter models control for stable, between-family differences, they comprise a stronger test of a causal relation. In standard, between-family models, parental monitoring and youths' depressive symptoms were negatively associated (standardized [Formula: see text]= -0.22, 95% CI = [-0.25, -0.20], p < 0.001). In first-differenced, within-family models, the association shrunk by about 55% (standardized [Formula: see text]= -0.10, 95% CI = [-0.12, -0.08], p < 0.001). The magnitude of within-family association remained similar when adjusting for potential time-varying confounders and did not vary significantly by youth sex, age, or history of depressive disorder. Thus, in this community-based sample, much of the prima facie association between parental knowledge/monitoring and youths' depressive symptoms was driven by confounding variables rather than a causal process. Given the evidence to date, a clinical focus on increasing parental knowledge/monitoring should not be expected to produce meaningfully large improvements in youths' depression.

Measuring Emotion Dysregulation in Children With Attention-Deficit/Hyperactivity Disorder: Revisiting the Factor Structure of the Emotion Regulation Checklist

Emotion dysregulation (ED) is prevalent among youth with Attention-Deficit/Hyperactivity Disorder (ADHD) and significantly impacts functioning. Nuanced measurement of ED is central to understanding its role in this disorder and informing treatment approaches. The present study examined the factor structure of the Emotion Regulation Checklist (ERC) among children with ADHD with and without Oppositional Defiant Disorder (ODD). Exploratory factor analysis (EFA) conducted in a sample of 328 youth (mean age = 6.08) with ADHD indicated a four-factor solution, comprised of the following factors: Negative Emotion Lability, Positive Emotion Lability, Socially Appropriate Affect, and Socially Incongruent Affect. The Negative and Positive Emotion Lability subscales assess the reactivity of negatively and positively valenced emotions, respectively. The Socially Appropriate and Socially Incongruent Affect subscales provide an assessment of social-emotional functioning. All subscales discriminated between children with ADHD only and ADHD with co-morbid ODD, such that children with ODD had greater emotional lability and social-emotional difficulties. This revised factor structure of the ERC facilitates a uniquely brief, yet multifaceted and specific, assessment of emotional difficulties in children with ADHD that can inform treatment planning and operationalize emotional reactivity and social-emotional functioning in future research efforts.

Resilience to COVID-19: Socioeconomic Disadvantage Associated With Positive Caregiver-Youth Communication and Youth Preventative Actions

Socioeconomic disadvantage is associated with larger COVID-19 disease burdens and pandemic-related economic impacts. We utilized the longitudinal Adolescent Brain Cognitive Development Study to understand how family- and neighborhood-level socioeconomic disadvantage relate to disease burden, family communication, and preventative responses to the pandemic in over 6,000 youth-caregiver dyads. Data were collected at three timepoints (May-August 2020). Here, we show that both family- and neighborhood-level disadvantage were associated with caregivers' reports of greater family COVID-19 disease burden, less perceived exposure risk, more frequent caregiver-youth conversations about COVID-19 risk/prevention and reassurance, and greater youth preventative behaviors. Families with more socioeconomic disadvantage may be adaptively incorporating more protective strategies to reduce emotional distress and likelihood of COVID-19 infection. The results highlight the importance of caregiver-youth communication and disease-preventative practices for buffering the economic and disease burdens of COVID-19, along with policies and programs that reduce these burdens for families with socioeconomic disadvantage.

Adverse childhood experiences predict neurite density differences in young children with and without attention deficit hyperactivity disorder

Adverse childhood experiences (ACEs) put millions of children at risk for later health problems. As childhood represents a critical developmental period, it is important to understand how ACEs impact brain development in young children. In addition, children with attention-deficit/hyperactivity disorder (ADHD) are more likely than typically developing (TD) peers to experience ACEs. Therefore, the current study examined the impact of ACEs on early brain development, using a cumulative risk approach, in a large sample of children with and without ADHD. We examined 198 young children (M_age  = 5.45, 82.3% Hispanic/Latino; 52.5% ADHD) across measures of brain volume, cortical thickness, neurite density index (NDI), and orientation dispersion index (ODI). For the NDI measure, there was a significant interaction between group and cumulative risk (ß = .18, p = .048), such that for children with ADHD, but not TD children, greater cumulate risk was associated with increased NDI in corpus callosum. No other interactions were detected. Additionally, when examining across groups, greater cumulative risk was associated with reduced ODI and volume in the cerebellum, although these findings did not survive a correction for multiple comparisons. Our results highlight the role early cumulative ACEs play in brain development across TD and children with ADHD.

Individual differences in white matter of the uncinate fasciculus and inferior fronto-occipital fasciculus: possible early biomarkers for callous-unemotional behaviors in young children with disruptive behavior problems

BACKGROUND

Callous-unemotional (CU) behaviors are important for identifying severe patterns of conduct problems (CP). One major fiber tract implicated in the development of CP is the uncinate fasciculus (UF), which connects amygdala and orbitofrontal cortex (OFC). The goals of the current study were to (a) explore differences in the white matter microstructure in the UF and other major fiber tracks between young typically developing (TD) children and those with a disruptive behavior disorder (DBD) and (b) explore, within the DBD group, whether individual differences in these white matter tracts relate to co-occurring CP and CU behaviors.

METHODS

Participants included 198 young children (69% boys, M_age  = 5.66 years; 80% Latinx; 48.5% TD). CU behaviors and CP were measured via a combination of teacher/parent ratings. Non-invasive diffusion-weighted imaging (DWI) was used to measure fractional anisotropy (FA), an indirect indicator of white matter properties.

RESULTS

Relative to TD children, children in the DBD group had reduced FA on four out of the five fiber tracks we examined (except for cingulum and right ILF), even after accounting for whole brain FA, sex, movement, parental income, and IQ. Within the DBD group, no associations were found between CP and reduced white matter integrity across any of the fiber tracks examined. However, we found that even after accounting for CP, ADHD symptomology, and a host of covariates (whole brain FA, sex, movement, parental income, and IQ), CU behaviors were independently related to reduced FA in bilateral UF and left inferior fronto-occipital fasciculus (IFOF) in the DBD group, but this was not the case for TD children.

CONCLUSIONS

Alterations in the white matter microstructure within bilateral UF and left IFOF may be biomarkers of CU behaviors, even in very young children.

Clear Theories Are Needed to Interpret Differences: Perspectives on the Bilingual Advantage Debate

The heated debate regarding bilingual cognitive advantages remains ongoing. While there are many studies supporting positive cognitive effects of bilingualism, recent meta-analyses have concluded that there is no consistent evidence for a bilingual advantage. In this article we focus on several theoretical concerns. First, we discuss changes in theoretical frameworks, which have led to the development of insufficiently clear theories and hypotheses that are difficult to falsify. Next, we discuss the development of looking at bilingual experiences and the need to better understand language control. Last, we argue that the move from behavioural studies to a focus on brain plasticity is not going to solve the debate on cognitive effects, especially not when brain changes are interpreted in the absence of behavioural differences. Clearer theories on both behavioural and neural effects of bilingualism are needed. However, to achieve this, a solid understanding of both bilingualism and executive functions is needed first.

Demographic and mental health assessments in the adolescent brain and cognitive development study: Updates and age-related trajectories

The Adolescent Brain Cognitive Development (ABCD) Study of 11,880 youth incorporates a comprehensive range of measures assessing predictors and outcomes related to mental health across childhood and adolescence in participating youth, as well as information about family mental health history. We have previously described the logic and content of the mental health assessment battery at Baseline and 1-year follow-up. Here, we describe changes to that battery and issues and clarifications that have emerged, as well as additions to the mental health battery at the 2-, 3-, 4-, and 5-year follow-ups. We capitalize on the recent release of longitudinal data for caregiver and youth report of mental health data to evaluate trajectories of dimensions of psychopathology as a function of demographic factors. For both caregiver and self-reported mental health symptoms, males showed age-related decreases in internalizing and externalizing symptoms, while females showed an increase in internalizing symptoms with age. Multiple indicators of socioeconomic status (caregiver education, family income, financial adversity, neighborhood poverty) accounted for unique variance in both caregiver and youth-reported externalizing and internalizing symptoms. These data highlight the importance of examining developmental trajectories of mental health as a function of key factors such as sex and socioeconomic environment.

Meaningful associations in the adolescent brain cognitive development study

The Adolescent Brain Cognitive Development (ABCD) Study is the largest single-cohort prospective longitudinal study of neurodevelopment and children's health in the United States. A cohort of n = 11,880 children aged 9-10 years (and their parents/guardians) were recruited across 22 sites and are being followed with in-person visits on an annual basis for at least 10 years. The study approximates the US population on several key sociodemographic variables, including sex, race, ethnicity, household income, and parental education. Data collected include assessments of health, mental health, substance use, culture and environment and neurocognition, as well as geocoded exposures, structural and functional magnetic resonance imaging (MRI), and whole-genome genotyping. Here, we describe the ABCD Study aims and design, as well as issues surrounding estimation of meaningful associations using its data, including population inferences, hypothesis testing, power and precision, control of covariates, interpretation of associations, and recommended best practices for reproducible research, analytical procedures and reporting of results.

Early Adolescent Substance Use Before and During the COVID-19 Pandemic: A Longitudinal Survey in the ABCD Study Cohort

PURPOSE

Evaluate changes in early adolescent substance use during the coronavirus disease 2019 (COVID-19) pandemic using a prospective, longitudinal, nationwide cohort.

METHODS

Participants were enrolled in the Adolescent Brain Cognitive Development Study. A total of 7,842 youth (mean age = 12.4 years, range = 10.5-14.6) at 21 study sites across the U.S. completed a three-wave assessment of substance use between May and August 2020. Youth reported whether they had used alcohol, nicotine, cannabis, or other substances in the past 30 days. Data were linked to prepandemic surveys that the same youth had completed in the years 2018-2020, before the advent of the COVID-19 pandemic.

RESULTS

Past-30-day substance use remained stable in the 6 months since stay-at-home orders were first issued in U.S. states/counties; was primarily episodic (1-2 days in the past month); and was typically limited to a single substance. Using pretest/posttest and age-period designs, we found that compared to before the pandemic, fewer youth were using alcohol and more youth were using nicotine or misusing prescription drugs. During the pandemic, youth were more likely to use substances when they were more stressed by pandemic-related uncertainty; their family experienced material hardship; their parents used alcohol or drugs; or they experienced greater depression or anxiety. Neither engagement in social distancing nor worry about COVID-19 infection was associated with substance use. Several risk factors were stronger among older (vs. younger) adolescents.

CONCLUSIONS

Among youth in early adolescence, advent of the COVID-19 pandemic was associated with decreased use of alcohol and increased use of nicotine and misuse of prescription drugs.

In vivo restricted diffusion imaging (RDI) is sensitive to differences in axonal density in typical children and adults

The ability to dissociate axonal density in vivo from other microstructural properties is important for the diagnosis and treatment of neurologic disease, and new methods to do so are being developed. We investigated one such method-restricted diffusion imaging (RDI)-to see whether it can more accurately replicate histological axonal density patterns in the corpus callosum (CC) of adults and children compared to diffusion tensor imaging (DTI), neurite orientation dispersion and density imaging (NODDI), and generalized q-sampling imaging (GQI) methods. To do so, we compared known axonal density patterns defined by histology to diffusion-weighted imaging (DWI) scans of 840 healthy 20- to 40-year-old adults, and to DWI scans of 129 typically developing 7-month-old to 18-year-old children and adolescents. Contrast analyses were used to compare pattern similarities between the in vivo metric and previously published histological density models. We found that RDI was effective at mapping axonal density of small (Cohen's d = 2.60) and large fiber sizes (Cohen's d = 2.84) in adults. The same pattern was observed in the developing sample (Cohen's d = 3.09 and 3.78, respectively). Other metrics, notably NODDI's intracellular volume fraction in adults and GQI generalized fractional anisotropy in children, were also sensitive metrics. In conclusion, the study showed that the novel RDI metric is sensitive to density of small and large axons in adults and children, with both single- and multi-shell acquisition DWI data. Its effectiveness and availability to be used on standard as well as advanced DWI acquisitions makes it a promising method in clinical settings.

Baseline brain function in the preadolescents of the ABCD Study

The Adolescent Brain Cognitive Development (ABCD) Study® is a 10-year longitudinal study of children recruited at ages 9 and 10. A battery of neuroimaging tasks are administered biennially to track neurodevelopment and identify individual differences in brain function. This study reports activation patterns from functional MRI (fMRI) tasks completed at baseline, which were designed to measure cognitive impulse control with a stop signal task (SST; N = 5,547), reward anticipation and receipt with a monetary incentive delay (MID) task (N = 6,657) and working memory and emotion reactivity with an emotional N-back (EN-back) task (N = 6,009). Further, we report the spatial reproducibility of activation patterns by assessing between-group vertex/voxelwise correlations of blood oxygen level-dependent (BOLD) activation. Analyses reveal robust brain activations that are consistent with the published literature, vary across fMRI tasks/contrasts and slightly correlate with individual behavioral performance on the tasks. These results establish the preadolescent brain function baseline, guide interpretation of cross-sectional analyses and will enable the investigation of longitudinal changes during adolescent development.

Altered hippocampal microstructure and function in children who experienced Hurricane Irma

Hurricane Irma was the most powerful Atlantic hurricane in recorded history, displacing 6 million and killing over 120 people in the state of Florida alone. Unpredictable disasters like Irma are associated with poor cognitive and health outcomes that can disproportionately impact children. This study examined the effects of Hurricane Irma on the hippocampus and memory processes previously related to unpredictable stress. We used an innovative application of an advanced diffusion-weighted imaging technique, restriction spectrum imaging (RSI), to characterize hippocampal microstructure (i.e., cell density) in 9- to 10-year-old children who were exposed to Hurricane Irma relative to a non-exposed control group (i.e., assessed the year before Hurricane Irma). We tested the hypotheses that the experience of Hurricane Irma would be associated with decreases in: (a) hippocampal cellularity (e.g., neurogenesis), based on known associations between unpredictable stress and hippocampal alterations; and (b) hippocampal-related memory function as indexed by delayed recall. We show an association between decreased hippocampal cellularity and delayed recall memory in children who experienced Hurricane Irma relative to those who did not. These findings suggest an important role of RSI for assessing subtle microstructural changes related to functionally significant changes in the developing brain in response to environmental events.

Altered brain structures in the dorsal and ventral language pathways in individuals with and without developmental language disorder (DLD)

Developmental Language Disorder (DLD) is a neurodevelopmental disorder characterized by difficulty learning and using language, and this difficulty cannot be attributed to other developmental conditions. The aim of the current study was to examine structural differences in dorsal and ventral language pathways between adolescents and young adults with and without DLD (age range: 14-27 years) using anatomical magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI). Results showed age-related structural brain differences in both dorsal and ventral pathways in individuals with DLD. These findings provide evidence for neuroanatomical correlates of persistent language deficits in adolescents/young adults with DLD, and further suggest that this brain-language relationship in DLD is better characterized by taking account the dynamic course of the disorder along development.

The phonological loop: is speech special?

It has been proposed that the maintenance of phonological information in verbal working memory (vWM) is carried by a domain-specific short-term storage center-the phonological loop-which is composed of a phonological store and an articulatory rehearsal system. Several brain regions including the left posterior inferior frontal gyrus (pIFG) and anterior supramarginal gyri (aSMG) are thought to support these processes. However, recent behavioral evidence suggests that verbal and non-verbal auditory information may be processed as part of a unique domain general short-term storage center instead of through specialized subsystems such as the phonological loop. In the current study, we used a single-pulse transcranial magnetic stimulation (TMS)-delayed priming paradigm with speech (syllables) and acoustically complex non-speech sounds (bird songs) to examine whether the pIFG and aSMG are involved in the processing of verbal information or, alternatively, in the processing of any complex auditory information. Our results demonstrate that TMS delivered to both regions had an effect on performance for speech and non-speech stimuli, but the nature of the effect was different. That is, priming was reduced for the speech sounds because TMS facilitated the detection of different but not identical stimuli, and accuracy was decreased for non-speech sounds. Since TMS interfered with both speech and non-speech sounds, these findings support the existence of an auditory short-term storage center located within the dorsal auditory stream.

Measuring Cognitive Flexibility with the Flexible Item Selection Task: From fMRI Adaptation to Individual Connectome Mapping

Cognitive flexibility, the ability to appropriately adjust behavior in a changing environment, has been challenging to operationalize and validate in cognitive neuroscience studies. Here, we investigate neural activation and directed functional connectivity underlying cognitive flexibility using an fMRI-adapted version of the Flexible Item Selection Task (FIST) in adults (n = 32, ages 19-46 years). The fMRI-adapted FIST was reliable, showed comparable performance to the computer-based version of the task, and produced robust activation in frontoparietal, anterior cingulate, insular, and subcortical regions. During flexibility trials, participants directly engaged the left inferior frontal junction, which influenced activity in other cortical and subcortical regions. The strength of intrinsic functional connectivity between select brain regions was related to individual differences in performance on the FIST, but there was also significant individual variability in functional network topography supporting cognitive flexibility. Taken together, these results suggest that the FIST is a valid measure of cognitive flexibility, which relies on computations within a broad corticosubcortical network driven by inferior frontal junction engagement.

Image processing and analysis methods for the Adolescent Brain Cognitive Development Study

The Adolescent Brain Cognitive Development (ABCD) Study is an ongoing, nationwide study of the effects of environmental influences on behavioral and brain development in adolescents. The main objective of the study is to recruit and assess over eleven thousand 9-10-year-olds and follow them over the course of 10 years to characterize normative brain and cognitive development, the many factors that influence brain development, and the effects of those factors on mental health and other outcomes. The study employs state-of-the-art multimodal brain imaging, cognitive and clinical assessments, bioassays, and careful assessment of substance use, environment, psychopathological symptoms, and social functioning. The data is a resource of unprecedented scale and depth for studying typical and atypical development. The aim of this manuscript is to describe the baseline neuroimaging processing and subject-level analysis methods used by ABCD. Processing and analyses include modality-specific corrections for distortions and motion, brain segmentation and cortical surface reconstruction derived from structural magnetic resonance imaging (sMRI), analysis of brain microstructure using diffusion MRI (dMRI), task-related analysis of functional MRI (fMRI), and functional connectivity analysis of resting-state fMRI. This manuscript serves as a methodological reference for users of publicly shared neuroimaging data from the ABCD Study.

Structural Connections of Functionally Defined Human Insular Subdivisions

The organization of the human insular cortex has traditionally been considered as an anterior-posterior dichotomy, where anterior and posterior subdivisions have unique structural and functional connections. However, recent functional neuroimaging research proposes a tripartite organization where insular subdivisions have both unique and overlapping functional profiles. Studies examining unique profiles show that the dorsal anterior insula (dAI) has connections with frontal areas supporting higher-level cognitive processes, the ventral anterior insula (vAI) has connections with limbic areas supporting affective processes, and the posterior insula (PI) has connections with sensorimotor areas supporting interoceptive processes. Studies examining overlapping profiles demonstrate that all 3 subdivisions can also have similar functional profiles. The structural organization supporting a functional tripartite insula organization presenting with overlapping and unique connections is currently unknown. We used a large HARDI diffusion magnetic resonance imaging (MRI) dataset (n = 199) to demonstrate novel visualizations of insula white matter tracts supporting a tripartite structure-function insula organization. Overlapping connections of all 3 insula subdivisions consisted of association pathways (inferior fronto-occipital fasciculus, uncinate fasciculus, arcuate fasciculus) while unique connections included the corona radiata, subcortical-cortical tracts, and horizontal and u-shaped tracts. These results generally support a tripartite structure-function organization of the insular cortex, with subdivisions that exhibit both overlapping and unique connectivity profiles.

Author Correction: No evidence for a bilingual executive function advantage in the ABCD study

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

No evidence for a bilingual executive function advantage in the nationally representative ABCD study

Learning a second language in childhood is inherently advantageous for communication. However, parents, educators and scientists have been interested in determining whether there are additional cognitive advantages. One of the most exciting yet controversial1 findings about bilinguals is a reported advantage for executive function. That is, several studies suggest that bilinguals perform better than monolinguals on tasks assessing cognitive abilities that are central to the voluntary control of thoughts and behaviours-the so-called 'executive functions' (for example, attention, inhibitory control, task switching and resolving conflict). Although a number of small-2-4 and large-sample5,6 studies have reported a bilingual executive function advantage (see refs. 7-9 for a review), there have been several failures to replicate these findings10-15, and recent meta-analyses have called into question the reliability of the original empirical claims8,9. Here we show, in a very large, demographically representative sample (n = 4,524) of 9- to 10-year-olds across the United States, that there is little evidence for a bilingual advantage for inhibitory control, attention and task switching, or cognitive flexibility, which are key aspects of executive function. We also replicate previously reported disadvantages in English vocabulary in bilinguals7,16,17. However, these English vocabulary differences are substantially mitigated when we account for individual differences in socioeconomic status or intelligence. In summary, notwithstanding the inherently positive benefits of learning a second language in childhood18, we found little evidence that it engenders additional benefits to executive function development.

Diffusion weighted imaging evidence of extra-callosal pathways for interhemispheric communication after complete commissurotomy

The integrity of white matter architecture in the human brain is related to cognitive processing abilities. The corpus callosum is the largest white matter bundle interconnecting the two cerebral hemispheres. "Split-brain" patients in whom all cortical commissures have been severed to alleviate intractable epilepsy demonstrate remarkably intact cognitive abilities despite the lack of this important interhemispheric pathway. While it has often been speculated that there are compensatory alterations in the remaining interhemispheric fibers in split-brain patients several years post-commissurotomy, this has never been directly shown. Here we examined extra-callosal pathways for interhemispheric communication in the brain of a patient who underwent complete cerebral commissurotomy using diffusion weighted imaging tractography. We found that compared with a healthy age-matched comparison group, the split-brain patient exhibited increased fractional anisotropy (FA) of the dorsal and ventral pontine decussations of the cortico-cerebellar interhemispheric pathways. Few differences were observed between the patient and the comparison group with respect to FA of other long-range intrahemispheric fibers. These results point to specific cerebellar anatomical substrates that may account for the spared interhemispheric coordination and intact cognitive abilities that have been extensively documented in this unique patient.

Laterality of the frontal aslant tract (FAT) explains externalizing behaviors through its association with executive function

We investigated the development of a recently identified white matter pathway, the frontal aslant tract (FAT) and its association with executive function and externalizing behaviors in a sample of 129 neurotypical male and female human children ranging in age from 7 months to 19 years. We found that the FAT could be tracked in 92% of those children, and that the pathway showed age-related differences into adulthood. The change in white matter microstructure was very rapid until about 6 years, and then plateaued, only to show age-related increases again after the age of 11 years. In a subset of those children (5-18 years; n = 70), left laterality of the microstructural properties of the FAT was associated with greater attention problems as measured by the Child Behavior Checklist (CBCL). However, this relationship was fully mediated by higher executive dysfunction as measured by the Behavior Rating Inventory of Executive Function (BRIEF). This relationship was specific to the FAT-we found no relationship between laterality of a control pathway, or of the white matter of the brain in general, and attention and executive function. These findings suggest that the degree to which the developing brain favors a right lateralized structural dominance of the FAT is directly associated with executive function and attention. This novel finding provides a new potential structural biomarker to assess attention deficit hyperactivity disorder (ADHD) and associated executive dysfunction during development.

The role of the arcuate and middle longitudinal fasciculi in speech perception in noise in adulthood

In this article, we used High Angular Resolution Diffusion Imaging (HARDI) with advanced anatomically constrained particle filtering tractography to investigate the role of the arcuate fasciculus (AF) and the middle longitudinal fasciculus (MdLF) in speech perception in noise in younger and older adults. Fourteen young and 15 elderly adults completed a syllable discrimination task in the presence of broadband masking noise. Mediation analyses revealed few effects of age on white matter (WM) in these fascicles but broad effects of WM on speech perception, independently of age, especially in terms of sensitivity and criterion (response bias), after controlling for individual differences in hearing sensitivity and head size. Indirect (mediated) effects of age on speech perception through WM microstructure were also found, after controlling for individual differences in hearing sensitivity and head size, with AF microstructure related to sensitivity, response bias and phonological priming, and MdLF microstructure more strongly related to response bias. These findings suggest that pathways of the perisylvian region contribute to speech processing abilities, with relatively distinct contributions for the AF (sensitivity) and MdLF (response bias), indicative of a complex contribution of both phonological and cognitive processes to age-related speech perception decline. These results provide new and important insights into the roles of these pathways as well as the factors that may contribute to elderly speech perception deficits. They also highlight the need for a greater focus to be placed on studying the role of WM microstructure to understand cognitive aging.

The frontal aslant tract (FAT) and its role in speech, language and executive function

In this review, we examine the structural connectivity of a recently-identified fiber pathway, the frontal aslant tract (FAT), and explore its function. We first review structural connectivity studies using tract-tracing methods in non-human primates, and diffusion-weighted imaging and electrostimulation in humans. These studies suggest a monosynaptic connection exists between the lateral inferior frontal gyrus and the pre-supplementary and supplementary motor areas of the medial superior frontal gyrus. This connection is termed the FAT. We then review research on the left FAT's putative role in supporting speech and language function, with particular focus on speech initiation, stuttering and verbal fluency. Next, we review research on the right FAT's putative role supporting executive function, namely inhibitory control and conflict monitoring for action. We summarize the extant body of empirical work by suggesting that the FAT plays a domain general role in the planning, timing, and coordination of sequential motor movements through the resolution of competition among potential motor plans. However, we also propose some domain specialization across the hemispheres. On the left hemisphere, the circuit is proposed to be specialized for speech actions. On the right hemisphere, the circuit is proposed to be specialized for general action control of the organism, especially in the visuo-spatial domain. We close the review with a discussion of the clinical significance of the FAT, and suggestions for further research on the pathway.

Cerebellar Contributions to Language in Typical and Atypical Development: A Review

In this review, we present the growing literature suggesting, from a variety of angles, that the cerebellum contributes to higher-order cognitive functions, rather than simply sensorimotor functions, and more specifically to language and its development. The cerebellum's association with language function is determined by the specific cortico-cerebellar connectivity to the right cerebellum from the left cortical hemisphere. The findings we review suggest that the cerebellum plays an important role as part of a broader language network, and also implies that the cerebellum may be a potential new therapeutic target to treat speech and language deficits, especially during development.

Broca and Wernicke are dead, or moving past the classic model of language neurobiology

With the advancement of cognitive neuroscience and neuropsychological research, the field of language neurobiology is at a cross-roads with respect to its framing theories. The central thesis of this article is that the major historical framing model, the Classic "Wernicke-Lichtheim-Geschwind" model, and associated terminology, is no longer adequate for contemporary investigations into the neurobiology of language. We argue that the Classic model (1) is based on an outdated brain anatomy; (2) does not adequately represent the distributed connectivity relevant for language, (3) offers a modular and "language centric" perspective, and (4) focuses on cortical structures, for the most part leaving out subcortical regions and relevant connections. To make our case, we discuss the issue of anatomical specificity with a focus on the contemporary usage of the terms "Broca's and Wernicke's area", including results of a survey that was conducted within the language neurobiology community. We demonstrate that there is no consistent anatomical definition of "Broca's and Wernicke's Areas", and propose to replace these terms with more precise anatomical definitions. We illustrate the distributed nature of the language connectome, which extends far beyond the single-pathway notion of arcuate fasciculus connectivity established in Geschwind's version of the Classic Model. By illustrating the definitional confusion surrounding "Broca's and Wernicke's areas", and by illustrating the difficulty integrating the emerging literature on perisylvian white matter connectivity into this model, we hope to expose the limits of the model, argue for its obsolescence, and suggest a path forward in defining a replacement.

Fiber tracking of the frontal aslant tract and subcomponents of the arcuate fasciculus in 5-8-year-olds: Relation to speech and language function

Long association cortical fiber pathways support developing networks for speech and language, but we do not have a clear understanding of how they develop in early childhood. Using diffusion-weighted imaging (DWI) we tracked the frontal aslant tract (FAT), arcuate fasciculus (AF), and AF segments (anterior, long, posterior) in 19 typical 5-8-year-olds, an age range in which significant improvement in speech and language function occurs. While the microstructural properties of the FAT and the right AF did not show age-related differences over the age range we investigated, the left AF evidenced increasing fractional anisotropy with age. Microstructural properties of the AF in both hemispheres, however, predicted receptive and expressive language. Length of the left FAT also predicted receptive language, which provides initial suggestion that this pathway is important for language development. These findings have implications for models of language development and for models of the neurobiology of language more broadly.

Stuck in the moment: cognitive inflexibility in preschoolers following an extended time period

Preschoolers display surprising inflexibility in problem solving, but seem to approach new challenges with a fresh slate. We provide evidence that while the former is true the latter is not. Here, we examined whether brief exposure to stimuli can influence children's problem solving following several weeks after first exposure to the stimuli. We administered a common executive function task, the Dimensional Change Card Sort, which requires children to sort picture cards by one dimension (e.g., color) and then switch to sort the same cards by a conflicting dimension (e.g., shape). After a week or after a month delay, we administered the second rule again. We found that 70% of preschoolers continued to sort by the initial sorting rule, even after a month delay, and even though they are explicitly told what to do. We discuss implications for theories of executive function development, and for classroom learning.

The Language Connectome

The field of the neurobiology of language is experiencing a paradigm shift in which the predominant Broca–Wernicke–Geschwind language model is being revised in favor of models that acknowledge that language is processed within a distributed cortical and subcortical system. While it is important to identify the brain regions that are part of this system, it is equally important to establish the anatomical connectivity supporting their functional interactions. The most promising framework moving forward is one in which language is processed via two interacting “streams”—a dorsal and ventral stream—anchored by long association fiber pathways, namely the superior longitudinal fasciculus/arcuate fasciculus, uncinate fasciculus, inferior longitudinal fasciculus, inferior fronto-occipital fasciculus, and two less well-established pathways, the middle longitudinal fasciculus and extreme capsule. In this article, we review the most up-to-date literature on the anatomical connectivity and function of these pathways. We also review and emphasize the importance of the often overlooked cortico-subcortical connectivity for speech via the “motor stream” and associated fiber systems, including a recently identified cortical association tract, the frontal aslant tract. These pathways anchor the distributed cortical and subcortical systems that implement speech and language in the human brain.

Frontal and temporal contributions to understanding the iconic co-speech gestures that accompany speech

In everyday conversation, listeners often rely on a speaker's gestures to clarify any ambiguities in the verbal message. Using fMRI during naturalistic story comprehension, we examined which brain regions in the listener are sensitive to speakers' iconic gestures. We focused on iconic gestures that contribute information not found in the speaker's talk, compared with those that convey information redundant with the speaker's talk. We found that three regions-left inferior frontal gyrus triangular (IFGTr) and opercular (IFGOp) portions, and left posterior middle temporal gyrus (MTGp)--responded more strongly when gestures added information to nonspecific language, compared with when they conveyed the same information in more specific language; in other words, when gesture disambiguated speech as opposed to reinforced it. An increased BOLD response was not found in these regions when the nonspecific language was produced without gesture, suggesting that IFGTr, IFGOp, and MTGp are involved in integrating semantic information across gesture and speech. In addition, we found that activity in the posterior superior temporal sulcus (STSp), previously thought to be involved in gesture-speech integration, was not sensitive to the gesture-speech relation. Together, these findings clarify the neurobiology of gesture-speech integration and contribute to an emerging picture of how listeners glean meaning from gestures that accompany speech.

Beyond the arcuate fasciculus: consensus and controversy in the connectional anatomy of language

The growing consensus that language is distributed into large-scale cortical and subcortical networks has brought with it an increasing focus on the connectional anatomy of language, or how particular fibre pathways connect regions within the language network. Understanding connectivity of the language network could provide critical insights into function, but recent investigations using a variety of methodologies in both humans and non-human primates have provided conflicting accounts of pathways central to language. Some of the pathways classically considered language pathways, such as the arcuate fasciculus, are now argued to be domain-general rather than specialized, which represents a radical shift in perspective. Other pathways described in the non-human primate remain to be verified in humans. In this review, we examine the consensus and controversy in the study of fibre pathway connectivity for language. We focus on seven fibre pathways-the superior longitudinal fasciculus and arcuate fasciculus, the uncinate fasciculus, extreme capsule, middle longitudinal fasciculus, inferior longitudinal fasciculus and inferior fronto-occipital fasciculus-that have been proposed to support language in the human. We examine the methods in humans and non-human primate used to investigate the connectivity of these pathways, the historical context leading to the most current understanding of their anatomy, and the functional and clinical correlates of each pathway with reference to language. We conclude with a challenge for researchers and clinicians to establish a coherent framework within which fibre pathway connectivity can be systematically incorporated to the study of language.

A network model of observation and imitation of speech

Much evidence has now accumulated demonstrating and quantifying the extent of shared regional brain activation for observation and execution of speech. However, the nature of the actual networks that implement these functions, i.e., both the brain regions and the connections among them, and the similarities and differences across these networks has not been elucidated. The current study aims to characterize formally a network for observation and imitation of syllables in the healthy adult brain and to compare their structure and effective connectivity. Eleven healthy participants observed or imitated audiovisual syllables spoken by a human actor. We constructed four structural equation models to characterize the networks for observation and imitation in each of the two hemispheres. Our results show that the network models for observation and imitation comprise the same essential structure but differ in important ways from each other (in both hemispheres) based on connectivity. In particular, our results show that the connections from posterior superior temporal gyrus and sulcus to ventral premotor, ventral premotor to dorsal premotor, and dorsal premotor to primary motor cortex in the left hemisphere are stronger during imitation than during observation. The first two connections are implicated in a putative dorsal stream of speech perception, thought to involve translating auditory speech signals into motor representations. Thus, the current results suggest that flow of information during imitation, starting at the posterior superior temporal cortex and ending in the motor cortex, enhances input to the motor cortex in the service of speech execution.

Sources of Cognitive Inflexibility in Set-Shifting Tasks: Insights Into Developmental Theories From Adult Data

Two experiments examined processes underlying cognitive inflexibility in set-shifting tasks typically used to assess the development of executive function in children. Adult participants performed a Flexible Item Selection Task (FIST) that requires shifting from categorizing by one dimension (e.g., color) to categorizing by a second orthogonal dimension (e.g., shape). The experiments showed performance of the FIST involves suppression of the representation of the ignored dimension; response times for selecting a target object in an immediately-following oddity task were slower when the oddity target was the previously-ignored stimulus of the FIST. However, proactive interference from the previously relevant stimulus dimension also impaired responding. The results are discussed with respect to two prominent theories of the source of difficulty for children and adults on dimensional shifting tasks: attentional inertia and negative priming. In contrast to prior work emphasizing one over the other process, the findings indicate that difficulty in the FIST, and by extension other set-shifting tasks, can be attributed to both the need to shift away from the previously attended representation (attentional inertia), and the need to shift to the previously ignored representation (negative priming). Results are discussed in relation to theoretical explanations for cognitive inflexibility in adults and children.

Gesture in the developing brain

Speakers convey meaning not only through words, but also through gestures. Although children are exposed to co-speech gestures from birth, we do not know how the developing brain comes to connect meaning conveyed in gesture with speech. We used functional magnetic resonance imaging (fMRI) to address this question and scanned 8- to 11-year-old children and adults listening to stories accompanied by hand movements, either meaningful co-speech gestures or meaningless self-adaptors. When listening to stories accompanied by both types of hand movement, both children and adults recruited inferior frontal, inferior parietal, and posterior temporal brain regions known to be involved in processing language not accompanied by hand movements. There were, however, age-related differences in activity in posterior superior temporal sulcus (STSp), inferior frontal gyrus, pars triangularis (IFGTr), and posterior middle temporal gyrus (MTGp) regions previously implicated in processing gesture. Both children and adults showed sensitivity to the meaning of hand movements in IFGTr and MTGp, but in different ways. Finally, we found that hand movement meaning modulates interactions between STSp and other posterior temporal and inferior parietal regions for adults, but not for children. These results shed light on the developing neural substrate for understanding meaning contributed by co-speech gesture.

Neural development of networks for audiovisual speech comprehension

Everyday conversation is both an auditory and a visual phenomenon. While visual speech information enhances comprehension for the listener, evidence suggests that the ability to benefit from this information improves with development. A number of brain regions have been implicated in audiovisual speech comprehension, but the extent to which the neurobiological substrate in the child compares to the adult is unknown. In particular, developmental differences in the network for audiovisual speech comprehension could manifest through the incorporation of additional brain regions, or through different patterns of effective connectivity. In the present study we used functional magnetic resonance imaging and structural equation modeling (SEM) to characterize the developmental changes in network interactions for audiovisual speech comprehension. The brain response was recorded while children 8- to 11-years-old and adults passively listened to stories under audiovisual (AV) and auditory-only (A) conditions. Results showed that in children and adults, AV comprehension activated the same fronto-temporo-parietal network of regions known for their contribution to speech production and perception. However, the SEM network analysis revealed age-related differences in the functional interactions among these regions. In particular, the influence of the posterior inferior frontal gyrus/ventral premotor cortex on supramarginal gyrus differed across age groups during AV, but not A speech. This functional pathway might be important for relating motor and sensory information used by the listener to identify speech sounds. Further, its development might reflect changes in the mechanisms that relate visual speech information to articulatory speech representations through experience producing and perceiving speech.

Left hemisphere regions are critical for language in the face of early left focal brain injury

A predominant theory regarding early stroke and its effect on language development, is that early left hemisphere lesions trigger compensatory processes that allow the right hemisphere to assume dominant language functions, and this is thought to underlie the near normal language development observed after early stroke. To test this theory, we used functional magnetic resonance imaging to examine brain activity during category fluency in participants who had sustained pre- or perinatal left hemisphere stroke (n = 25) and in neurologically normal siblings (n = 27). In typically developing children, performance of a category fluency task elicits strong involvement of left frontal and lateral temporal regions and a lesser involvement of right hemisphere structures. In our cohort of atypically developing participants with early stroke, expressive and receptive language skills correlated with activity in the same left inferior frontal regions that support language processing in neurologically normal children. This was true independent of either the amount of brain injury or the extent that the injury was located in classical cortical language processing areas. Participants with bilateral activation in left and right superior temporal-inferior parietal regions had better language function than those with either predominantly left- or right-sided unilateral activation. The advantage conferred by left inferior frontal and bilateral temporal involvement demonstrated in our study supports a strong predisposition for typical neural language organization, despite an intervening injury, and argues against models suggesting that the right hemisphere fully accommodates language function following early injury.

Co-speech gestures influence neural activity in brain regions associated with processing semantic information

Everyday communication is accompanied by visual information from several sources, including co-speech gestures, which provide semantic information listeners use to help disambiguate the speaker's message. Using fMRI, we examined how gestures influence neural activity in brain regions associated with processing semantic information. The BOLD response was recorded while participants listened to stories under three audiovisual conditions and one auditory-only (speech alone) condition. In the first audiovisual condition, the storyteller produced gestures that naturally accompany speech. In the second, the storyteller made semantically unrelated hand movements. In the third, the storyteller kept her hands still. In addition to inferior parietal and posterior superior and middle temporal regions, bilateral posterior superior temporal sulcus and left anterior inferior frontal gyrus responded more strongly to speech when it was further accompanied by gesture, regardless of the semantic relation to speech. However, the right inferior frontal gyrus was sensitive to the semantic import of the hand movements, demonstrating more activity when hand movements were semantically unrelated to the accompanying speech. These findings show that perceiving hand movements during speech modulates the distributed pattern of neural activation involved in both biological motion perception and discourse comprehension, suggesting listeners attempt to find meaning, not only in the words speakers produce, but also in the hand movements that accompany speech.

The Role of Negative Priming in Preschoolers' Flexible Rule Use on the Dimensional Change Card Sort Task

Four experiments examined the development of negative priming (NP) in 3-5-year-old children using as a measure of children's executive function (EF) the dimensional change card sort (DCCS) task. In the NP version of the DCCS, the values of the sorting dimension that is relevant during the preswitch phase are removed during the postswitch phase. The experiments showed that the NP effect observed in the DCCS decreased during the preschool years, and they clarified the circumstances in which NP occurs. Taken together, the findings suggest that the development of EF in early childhood consists in part in disinhibiting attention to information that has previously been suppressed.