Maturation of large-scale brain systems over the first month of life.

The period immediately after birth is a critical developmental window, capturing rapid maturation of brain structure and a child's earliest experiences. Large-scale brain systems are present at delivery, but how these brain systems mature during this narrow window (i.e. first weeks of life) marked by heightened neuroplasticity remains uncharted. Using multivariate pattern classification techniques and functional connectivity magnetic resonance imaging, we detected robust differences in brain systems related to age in newborns (n = 262; R2 = 0.51). Development over the first month of life occurred brain-wide, but differed and was more pronounced in brain systems previously characterized as developing early (i.e. sensorimotor networks) than in those characterized as developing late (i.e. association networks). The cingulo-opercular network was the only exception to this organizing principle, illuminating its early role in brain development. This study represents a step towards a normative brain "growth curve" that could be used to identify atypical brain maturation in infancy.

Neurodevelopmental vulnerability to psychosis: developmentally-based methods enable detection of early life inhibitory control deficits that predict psychotic-like experiences at the transition to adolescence.

BACKGROUND: Inhibitory control develops in early childhood, and atypical development may be a measurable marker of risk for the later development of psychosis. Additionally, inhibitory control may be a target for intervention. METHODS: Behavioral performance on a developmentally appropriate Go/No-Go task including a frustration manipulation completed by children ages 3-5 years (early childhood; n = 107) was examined in relation to psychotic-like experiences (PLEs; 'tween'; ages 9-12), internalizing symptoms, and externalizing symptoms self-reported at long-term follow-up (pre-adolescence; ages 8-11). ERP N200 amplitude for a subset of these children (n = 34) with electrophysiological data during the task was examined as an index of inhibitory control. RESULTS: Children with lower accuracy on No-Go trials compared to Go trials in early childhood (F(1,101) = 3.976, p = 0.049), evidenced higher PLEs at the transition to adolescence 4-9 years later, reflecting a specific deficit in inhibitory control. No association was observed with internalizing or externalizing symptoms. Decreased accuracy during the frustration manipulation predicted higher internalizing, F(2,202) = 5.618, p = 0.004, and externalizing symptoms, F(2,202) = 4.663, p = 0.010. Smaller N200 amplitudes were observed on No-Go trials for those with higher PLEs, F(1,101) = 6.075, p = 0.020; no relationship was observed for internalizing or externalizing symptoms. CONCLUSIONS: Long-term follow-up demonstrates for the first time a specific deficit in inhibitory control behaviorally and electrophysiology, for individuals who later report more PLEs. Decreases in task performance under frustration induction indicated risk for internalizing and externalizing symptoms. These findings suggest that pathophysiological mechanisms for psychosis are relevant and discriminable in early childhood, and further, suggest an identifiable and potentially modifiable target for early intervention.

Predictive Utility of Irritability "In Context": Proof-of-Principle for an Early Childhood Mental Health Risk Calculator.

OBJECTIVE: We provide proof-of-principle for a mental health risk calculator advancing clinical utility of the irritability construct for identification of young children at high risk for common, early onsetting syndromes. METHOD: Data were harmonized from two longitudinal early childhood subsamples (total N = 403; 50.1% Male; 66.7% Nonwhite; Mage = 4.3 years). The independent subsamples were clinically enriched via disruptive behavior and violence (Subsample 1) and depression (Subsample 2). In longitudinal models, epidemiologic risk prediction methods for risk calculators were applied to test the utility of the transdiagnostic indicator, early childhood irritability, in the context of other developmental and social-ecological indicators to predict risk of internalizing/externalizing disorders at preadolescence (Mage = 9.9 years). Predictors were retained when they improved model discrimination (area under the receiver operating characteristic curve [AUC] and integrated discrimination index [IDI]) beyond the base demographic model. RESULTS: Compared to the base model, the addition of early childhood irritability and adverse childhood experiences significantly improved the AUC (0.765) and IDI slope (0.192). Overall, 23% of preschoolers went on to develop a preadolescent internalizing/externalizing disorder. For preschoolers with both elevated irritability and adverse childhood experiences, the likelihood of an internalizing/externalizing disorder was 39-66%. CONCLUSIONS: Predictive analytic tools enable personalized prediction of psychopathological risk for irritable young children, holding transformative potential for clinical translation.

Lability of prenatal stress during the COVID-19 pandemic links to negative affect in infancy.

The association between prenatal stress and children's socioemotional development is well established. The COVID-19 pandemic has been a particularly stressful period, which may impact the gestational environment. However, most studies to-date have examined prenatal stress at a single time point, potentially masking the natural variation in stress that occurs over time, especially during a time as uncertain as the pandemic. This study leveraged dense ecological momentary assessments from a prenatal randomized control trial to examine patterns of prenatal stress over a 14-week period (up to four assessments/day) in a U.S. sample of 72 mothers and infants. We first examined whether varied features of stress exposure (lability, mean, and baseline stress) differed depending on whether mothers reported on their stress before or during the pandemic. We next examined which features of stress were associated with 3-month-old infants' negative affect. We did not find differences in stress patterns before and during the pandemic. However, greater stress lability, accounting for baseline and mean stress, was associated with higher infant negative affect. These findings suggest that pathways from prenatal stress exposure to infant socioemotional development are complex, and close attention to stress patterns over time will be important for explicating these pathways.

Social EEG: A novel neurodevelopmental approach to studying brain-behavior links and brain-to-brain synchrony during naturalistic toddler-parent interactions.

Despite increasing emphasis on emergent brain-behavior patterns supporting language, cognitive, and socioemotional development in toddlerhood, methodologic challenges impede their characterization. Toddlers are notoriously difficult to engage in brain research, leaving a developmental window in which neural processes are understudied. Further, electroencephalography (EEG) and event-related potential paradigms at this age typically employ structured, experimental tasks that rarely reflect formative naturalistic interactions with caregivers. Here, we introduce and provide proof of concept for a new "Social EEG" paradigm, in which parent-toddler dyads interact naturally during EEG recording. Parents and toddlers sit at a table together and engage in different activities, such as book sharing or watching a movie. EEG is time locked to the video recording of their interaction. Offline, behavioral data are microcoded with mutually exclusive engagement state codes. From 216 sessions to date with 2- and 3-year-old toddlers and their parents, 72% of dyads successfully completed the full Social EEG paradigm, suggesting that it is possible to collect dual EEG from parents and toddlers during naturalistic interactions. In addition to providing naturalistic information about child neural development within the caregiving context, this paradigm holds promise for examination of emerging constructs such as brain-to-brain synchrony in parents and children.

Developmental changes in auditory-evoked neural activity underlie infants' links between language and cognition.

The power and precision with which humans link language to cognition is unique to our species. By 3-4 months of age, infants have already established this link: simply listening to human language facilitates infants' success in fundamental cognitive processes. Initially, this link to cognition is also engaged by a broader set of acoustic stimuli, including non-human primate vocalizations (but not other sounds, like backwards speech). But by 6 months, non-human primate vocalizations no longer confer this cognitive advantage that persists for speech. What remains unknown is the mechanism by which these sounds influence infant cognition, and how this initially broader set of privileged sounds narrows to only human speech between 4 and 6 months. Here, we recorded 4- and 6-month-olds' EEG responses to acoustic stimuli whose behavioral effects on infant object categorization have been previously established: infant-directed speech, backwards speech, and non-human primate vocalizations. We document that by 6 months, infants' 4-9 Hz neural activity is modulated in response to infant-directed speech and non-human primate vocalizations (the two stimuli that initially support categorization), but that 4-9 Hz neural activity is not modulated at either age by backward speech (an acoustic stimulus that doesn't support categorization at either age). These results advance the prior behavioral evidence to suggest that by 6 months, speech and non-human primate vocalizations elicit distinct changes in infants' cognitive state, influencing performance on foundational cognitive tasks such as object categorization.

Translating RDoC to Real-World Impact in Developmental Psychopathology: A Neurodevelopmental Framework for Application of Mental Health Risk Calculators.

The National Institute of Mental Health Research Domain Criteria's (RDoC) has prompted a paradigm shift from categorical psychiatric disorders to considering multiple levels of vulnerability for probabilistic risk of disorder. However, the lack of neurodevelopmentally-based tools for clinical decision-making has limited RDoC's real-world impact. Integration with developmental psychopathology principles and statistical methods actualize the clinical implementation of RDoC to inform neurodevelopmental risk. In this conceptual paper, we introduce the probabilistic mental health risk calculator as an innovation for such translation and lay out a research agenda for generating an RDoC- and developmentally-informed paradigm that could be applied to predict a range of developmental psychopathologies from early childhood to young adulthood. We discuss methods that weigh the incremental utility for prediction based on intensity and burden of assessment, the addition of developmental change patterns, considerations for assessing outcomes, and integrative data approaches. Throughout, we illustrate the risk calculator approach with different neurodevelopmental pathways and phenotypes. Finally, we discuss real-world implementation of these methods for improving early identification and prevention of developmental psychopathology. We propose that mental health risk calculators can build a needed bridge between RDoC's multiple units of analysis and developmental science.

Nonrapid eye movement sleep characteristics and relations with motor, memory, and cognitive ability from infancy to preadolescence.

Sleep plays a critical role in neural neurodevelopment. Hallmarks of sleep reflected in the electroencephalogram during nonrapid eye movement (NREM) sleep are associated with learning processes, cognitive ability, memory, and motor functioning. Research in adults is well-established; however, the role of NREM sleep in childhood is less clear. Growing evidence suggests the importance of two NREM sleep features: slow-wave activity and sleep spindles. These features may be critical for understanding maturational change and the functional role of sleep during development. Here, we review the literature on NREM sleep from infancy to preadolescence to provide insight into the network dynamics of the developing brain. The reviewed findings show distinct relations between topographical and maturational aspects of slow waves and sleep spindles; however, the direction and consistency of these relationships vary, and associations with cognitive ability remain unclear. Future research investigating the role of NREM sleep and development would benefit from longitudinal approaches, increased control for circadian and homeostatic influences, and in early childhood, studies recording daytime naps and overnight sleep to yield increased precision for detecting age-related change. Such evidence could help explicate the role of NREM sleep and provide putative physiological markers of neurodevelopment.

Moving the dial on prenatal stress mechanisms of neurodevelopmental vulnerability to mental health problems: A personalized prevention proof of concept.

Prenatal stress exposure increases vulnerability to virtually all forms of psychopathology. Based on this robust evidence base, we propose a "Mental Health, Earlier" paradigm shift for prenatal stress research, which moves from the documentation of stress-related outcomes to their prevention, with a focus on infant neurodevelopmental indicators of vulnerability to subsequent mental health problems. Achieving this requires an expansive team science approach. As an exemplar, we introduce the Promoting Healthy Brain Project (PHBP), a randomized trial testing the impact of the Wellness-4-2 personalized prenatal stress-reduction intervention on stress-related alterations in infant neurodevelopmental trajectories in the first year of life. Wellness-4-2 utilizes bio-integrated stress monitoring for just-in-time adaptive intervention. We highlight unique challenges and opportunities this novel team science approach presents in synergizing expertise across predictive analytics, bioengineering, health information technology, prevention science, maternal-fetal medicine, neonatology, pediatrics, and neurodevelopmental science. We discuss how innovations across many areas of study facilitate this personalized preventive approach, using developmentally sensitive brain and behavioral methods to investigate whether altering children's adverse gestational exposures, i.e., maternal stress in the womb, can improve their mental health outlooks. In so doing, we seek to propel developmental SEED research towards preventive applications with the potential to reduce the pernicious effect of prenatal stress on neurodevelopment, mental health, and wellbeing.

Putative protective neural mechanisms in prereaders with a family history of dyslexia who subsequently develop typical reading skills.

Developmental dyslexia affects 40-60% of children with a familial risk (FHD+) compared to a general prevalence of 5-10%. Despite the increased risk, about half of FHD+ children develop typical reading abilities (FHD+Typical). Yet the underlying neural characteristics of favorable reading outcomes in at-risk children remain unknown. Utilizing a retrospective, longitudinal approach, this study examined whether putative protective neural mechanisms can be observed in FHD+Typical at the prereading stage. Functional and structural brain characteristics were examined in 47 FHD+ prereaders who subsequently developed typical (n = 35) or impaired (n = 12) reading abilities and 34 controls (FHD-Typical). Searchlight-based multivariate pattern analyses identified distinct activation patterns during phonological processing between FHD+Typical and FHD-Typical in right inferior frontal gyrus (RIFG) and left temporo-parietal cortex (LTPC) regions. Follow-up analyses on group-specific classification patterns demonstrated LTPC hypoactivation in FHD+Typical compared to FHD-Typical, suggesting this neural characteristic as an FHD+ phenotype. In contrast, RIFG showed hyperactivation in FHD+Typical than FHD-Typical, and its activation pattern was positively correlated with subsequent reading abilities in FHD+ but not controls (FHD-Typical). RIFG hyperactivation in FHD+Typical was further associated with increased interhemispheric functional and structural connectivity. These results suggest that some protective neural mechanisms are already established in FHD+Typical prereaders supporting their typical reading development.

Understanding event-related potentials (ERPs) in clinical and basic language and communication disorders research: a tutorial.

BACKGROUND: Event-related potentials (ERPs), which are electrophysiological neural responses time-locked to a stimulus, have become an increasingly common tool in language and communication disorders research. They can provide complementary evidence to behavioural measures as well as unique perspectives on communication disorders. ERPs have the distinct advantage of providing precise information about the timing of neural processes and can be used in cases where it is difficult to obtain responses from participants, such as infants or individuals who are minimally verbal. However, clinicians and clinician-scientists rarely receive training in how to interpret ERP research. AIMS: To provide information that allows readers to better understand, interpret and evaluate research using ERPs. We focus on research related to communication sciences and disorders and the information that is most relevant to interpreting research articles. METHOD: We explain what ERPs are and how ERP data are collected, referencing key texts and primary research articles. Potential threats to validity, guidelines for interpreting data, and the pros and cons using of ERPs are discussed. Research in the area of paediatric language disorders is used as a model; common paradigms such as the semantic incongruity N400 and auditory mismatch negativity are used as tangible examples. With this foundation of understanding ERPs, the state of the field in terms of how ERPs are used and the ways they may inform the field are discussed. MAIN CONTRIBUTION: To date, no review has focused on ERPs as they relate to clinical or communication research. The main contribution of this review is that it provides practical information geared toward understanding ERP research. CONCLUSIONS: ERPs offer insights into neural processes supporting communication and can both complement behaviour and provide information that behavioural measures cannot. We encourage readers to evaluate articles using ERPs critically, effectively pushing the field forward through increased understanding and rigor. What this paper adds ERPs have become more prevalent in research relevant to communication sciences and disorders. In order for clinicians to review and evaluate this research, an understanding of ERPs is needed. This review adds to the field by providing an accessible description of what ERPs are, a description of what ERP components are, and the most relevant commonly used components, as well as how ERP data are recorded and processed. With this foundational understanding of how ERPs work, guidelines for the interpretation of ERP data are given. Though few ERP studies currently have direct implications for clinical practice, we discuss several ways through which ERPs can impact clinical practice in future, by providing information that cannot be obtained by behaviour alone about the aetiology of disorders, and as potential biomarkers of disorder or treatment response.

The relationship between socioeconomic status and white matter microstructure in pre-reading children: A longitudinal investigation.

Reading is a learned skill crucial for educational attainment. Children from families of lower socioeconomic status (SES) tend to have poorer reading performance and this gap widens across years of schooling. Reading relies on the orchestration of multiple neural systems integrated via specific white-matter pathways, but there is limited understanding about whether these pathways relate differentially to reading performance depending on SES background. Kindergarten white-matter FA and second-grade reading outcomes were investigated in an SES-diverse sample of 125 children. The three left-hemisphere white-matter tracts most associated with reading, and their right-hemisphere homologs, were examined: arcuate fasciculus (AF), superior longitudinal fasciculus (SLF), and inferior longitudinal fasciculus (ILF). There was a significant and positive association between SES and fractional anisotropy (FA) in the bilateral ILF in kindergarten. SES moderated the association between kindergarten ILF and second grade reading performance, such that it was positive in lower-SES children, but not significant in higher-SES children. These results have implications for understanding the role of the environment in the development of the neural pathways that support reading.

Future Directions for Early Childhood Prevention of Mental Disorders: A Road Map to Mental Health, Earlier.

Mental disorders are the predominant chronic diseases of youth, with substantial life span morbidity and mortality. A wealth of evidence demonstrates that the neurodevelopmental roots of common mental health problems are present in early childhood. Unfortunately, this has not been translated to systematic strategies for improving population-level mental health at this most malleable neurodevelopmental period. We lay out a translational Mental Health, Earlier road map as a key future direction for prevention of mental disorder. This paradigm shift aims to reduce population attributable risk of mental disorder emanating from early life, by preventing, attenuating, or delaying onset/course of chronic psychopathology via the promotion of self-regulation in early childhood within large-scale health care delivery systems. The Earlier Pillar rests on a "science of when to worry" that (a) optimizes clinical assessment methods for characterizing probabilistic clinical risk beginning in infancy via deliberate incorporation of neurodevelopmental heterogeneity, and (b) universal primary-care-based screening targeting patterns of dysregulated irritability as a robust transdiagnostic marker of vulnerability to life span mental health problems. The core of the Healthier Pillar is provision of low-intensity selective intervention promoting self-regulation for young children with developmentally atypical patterns of irritability within an implementation science framework in pediatric primary care to ensure highest population impact and sustainability. These Mental Health, Earlier strategies hold much promise for transforming clinical outlooks and ensuring young children's mental health and well-being in a manner that reverberates throughout the life span.

Temporally sensitive neural measures of inhibition in preschool children across a spectrum of irritability.

Irritability is a prominent feature of chronic mental disorders and a developmental marker of their early emergence. The most salient feature of irritability in early childhood is temper tantrums. While temper tantrums are normative in young children, they can be clinically concerning when they are dysregulated, very frequent, and/or occur in unexpected contexts. The present study uses behavioral and event-related brain potential (ERP) measures to characterize the relationship between irritability and neural markers of response inhibition in very young children. Forty-six children (ages 4-7 years) completed a go/no-go task under nonfrustrating and frustrating conditions. ERPs elicited by go and no-go stimuli were examined as a function of frustration condition and irritability, operationalized via the well-validated Temper Loss scale of the Multidimensional Assessment Profile of Disruptive Behavior (MAP-DB). Higher Temper Loss scores were associated with larger N2no-go amplitudes and reduced no-go accuracy during frustration. This suggests that higher levels of irritability corresponded with increased conflict monitoring and poorer task performance during frustration. These findings add to a developing literature identifying the neurocognitive markers of varying levels of irritability in young children.

Relations Between Toddler Expressive Language and Temper Tantrums in a Community Sample.

This study examined the frequent clinical observation that toddlers with less expressive language have more severe temper tantrums. A representative sample of 2,001 mothers reported on their toddler's expressive vocabulary and frequency of different temper tantrum behaviors, a prominent feature of irritability and an emergent marker of mental health risk. Results revealed that 12- to 38-month-olds with fewer spoken words demonstrated more severe (frequent and dysregulated) temper tantrums. Toddlers who were late talkers at 24-30 months also had more severe tantrums; their relative risk of having severe tantrums was 1.96 times greater than peers with typical language. These results are the first to show that language and temper tantrums are related, and that this relation is present in the second year of life. These findings point to the importance of assessing both language and mental health risk in order to promote earlier identification and intervention for early childhood disorders.

Early development of letter specialization in left fusiform is associated with better word reading and smaller fusiform face area.

A functional region of left fusiform gyrus termed "the visual word form area" (VWFA) develops during reading acquisition to respond more strongly to printed words than to other visual stimuli. Here, we examined responses to letters among 5- and 6-year-old early kindergarten children (N = 48) with little or no school-based reading instruction who varied in their reading ability. We used functional magnetic resonance imaging (fMRI) to measure responses to individual letters, false fonts, and faces in left and right fusiform gyri. We then evaluated whether signal change and size (spatial extent) of letter-sensitive cortex (greater activation for letters versus faces) and letter-specific cortex (greater activation for letters versus false fonts) in these regions related to (a) standardized measures of word-reading ability and (b) signal change and size of face-sensitive cortex (fusiform face area or FFA; greater activation for faces versus letters). Greater letter specificity, but not letter sensitivity, in left fusiform gyrus correlated positively with word reading scores. Across children, in the left fusiform gyrus, greater size of letter-sensitive cortex correlated with lesser size of FFA. These findings are the first to suggest that in beginning readers, development of letter responsivity in left fusiform cortex is associated with both better reading ability and also a reduction of the size of left FFA that may result in right-hemisphere dominance for face perception.

Longitudinal stability of pre-reading skill profiles of kindergarten children: implications for early screening and theories of reading.

Research suggests that early identification of developmental dyslexia is important for mitigating the negative effects of dyslexia, including reduced educational attainment and increased socioemotional difficulties. The strongest pre-literacy predictors of dyslexia are rapid automatized naming (RAN), phonological awareness (PA), letter knowledge, and verbal short-term memory. The relationship among these constructs has been debated, and several theories have emerged to explain the unique role of each in reading ability/disability. Furthermore, the stability of identification of risk based on these measures varies widely across studies, due in part to the different cut-offs employed to designate risk. We applied a latent profile analysis technique with a diverse sample of 1215 kindergarten and pre-kindergarten students from 20 schools, to investigate whether PA, RAN, letter knowledge, and verbal short-term memory measures differentiated between homogenous profiles of performance on these measures. Six profiles of performance emerged from the data: average performers, below average performers, high performers, PA risk, RAN risk, and double-deficit risk (both PA and RAN). A latent class regression model was employed to investigate the longitudinal stability of these groups in a representative subset of children (n = 95) nearly two years later, at the end of 1st grade. Profile membership in the spring semester of pre-kindergarten or fall semester of kindergarten was significantly predictive of later reading performance, with the specific patterns of performance on the different constructs remaining stable across the years. There was a higher frequency of PA and RAN deficits in children from lower socioeconomic status (SES) backgrounds. There was no evidence for the IQ-achievement discrepancy criterion traditionally used to diagnose dyslexia. Our results support the feasibility of early identification of dyslexia risk and point to the heterogeneity of risk profiles. These findings carry important implications for improving outcomes for children with dyslexia, based on more targeted interventions.

Tracking the roots of reading ability: white matter volume and integrity correlate with phonological awareness in prereading and early-reading kindergarten children.

Developmental dyslexia, an unexplained difficulty in learning to read, has been associated with alterations in white matter organization as measured by diffusion-weighted imaging. It is unknown, however, whether these differences in structural connectivity are related to the cause of dyslexia or if they are consequences of reading difficulty (e.g., less reading experience or compensatory brain organization). Here, in 40 kindergartners who had received little or no reading instruction, we examined the relation between behavioral predictors of dyslexia and white matter organization in left arcuate fasciculus, inferior longitudinal fasciculus, and the parietal portion of the superior longitudinal fasciculus using probabilistic tractography. Higher composite phonological awareness scores were significantly and positively correlated with the volume of the arcuate fasciculus, but not with other tracts. Two other behavioral predictors of dyslexia, rapid naming and letter knowledge, did not correlate with volumes or diffusion values in these tracts. The volume and fractional anisotropy of the left arcuate showed a particularly strong positive correlation with a phoneme blending test. Whole-brain regressions of behavioral scores with diffusion measures confirmed the unique relation between phonological awareness and the left arcuate. These findings indicate that the left arcuate fasciculus, which connects anterior and posterior language regions of the human brain and which has been previously associated with reading ability in older individuals, is already smaller and has less integrity in kindergartners who are at risk for dyslexia because of poor phonological awareness. These findings suggest a structural basis of behavioral risk for dyslexia that predates reading instruction.

Developmental Trajectories of Irritability across the Transition to Toddlerhood: Associations with Effortful Control and Psychopathology.

Preschool-age irritability is a transdiagnostic marker of internalizing and externalizing problems. However, researchers have generally been reluctant to examine irritability within a clinically salient framework at younger ages due to some instability during the "terrible twos" period. Developmentally sensitive and dense measurements to capture intra- and inter-individual variability, as well as exploration of developmental processes that predict change, are needed. This study aimed to examine (1) the trajectories of irritability at the transition to toddlerhood (12-24 months of age) using repeated measures, (2) whether effortful control was associated with individual differences in level and growth rate of irritability, and (3) whether individual differences in the irritability trajectories were associated with later psychopathology. Families were recruited when the child was 12-18 months old (N = 333, 45.65% female). Mothers reported on their toddler's irritability at baseline and every two months until a follow-up laboratory assessment approximately one year later. Effortful control was measured at baseline. Clinical internalizing/externalizing symptoms were measured at the follow-up assessment. Hierarchical linear models revealed an increase in irritability over time, yet there was relatively little within-person variability. Effortful control was only associated with the level of irritability and not growth rate. Level of irritability was associated with internalizing, externalizing, and combined symptoms, but growth rate was not. Findings suggest intraindividual stability in irritability at the transition to toddlerhood and the possibility that screening for elevated irritability at toddler age is meaningful.

Brain basis of phonological awareness for spoken language in children and its disruption in dyslexia.

Phonological awareness, knowledge that speech is composed of syllables and phonemes, is critical for learning to read. Phonological awareness precedes and predicts successful transition from language to literacy, and weakness in phonological awareness is a leading cause of dyslexia, but the brain basis of phonological awareness for spoken language in children is unknown. We used functional magnetic resonance imaging to identify the neural correlates of phonological awareness using an auditory word-rhyming task in children who were typical readers or who had dyslexia (ages 7-13) and a younger group of kindergarteners (ages 5-6). Typically developing children, but not children with dyslexia, recruited left dorsolateral prefrontal cortex (DLPFC) when making explicit phonological judgments. Kindergarteners, who were matched to the older children with dyslexia on standardized tests of phonological awareness, also recruited left DLPFC. Left DLPFC may play a critical role in the development of phonological awareness for spoken language critical for reading and in the etiology of dyslexia.