Striatal and Behavioral Responses to Reward Vary by Socioeconomic Status in Adolescents.

Disparities in socioeconomic status (SES) lead to unequal access to financial and social support. These disparities are believed to influence reward sensitivity, which in turn are hypothesized to shape how individuals respond to and pursue rewarding experiences. However, surprisingly little is known about how SES shapes reward sensitivity in adolescence. Here, we investigated how SES influenced adolescent responses to reward, both in behavior and the striatum-a brain region that is highly sensitive to reward. We examined responses to both immediate reward (tracked by phasic dopamine) and average reward rate fluctuations (tracked by tonic dopamine) as these distinct signals independently shape learning and motivation. Adolescents (n = 114; 12-14 years; 58 female) performed a gambling task during functional magnetic resonance imaging. We manipulated trial-by-trial reward and loss outcomes, leading to fluctuations between periods of reward scarcity and abundance. We found that a higher reward rate hastened behavioral responses, and increased guess switching, consistent with the idea that reward abundance increases response vigor and exploration. Moreover, immediate reward reinforced previously rewarding decisions (win-stay, lose-switch) and slowed responses (postreward pausing), particularly when rewards were scarce. Notably, lower-SES adolescents slowed down less after rare rewards than higher-SES adolescents. In the brain, striatal activations covaried with the average reward rate across time and showed greater activations during rewarding blocks. However, these striatal effects were diminished in lower-SES adolescents. These findings show that the striatum tracks reward rate fluctuations, which shape decisions and motivation. Moreover, lower SES appears to attenuate reward-driven behavioral and brain responses.

Considering intersectionality and interacting levels of early intervention on early brain development-a commentary on Nelson et al. (2023).

It has long been recognized that an individual's experiences can metaphorically 'get under the skin' and become biologically embedded, thus affecting behavior and life outcomes (Hertzman, 2012). While this term is most often used to describe how adverse experiences influence biological process, it is rarely discussed how the same can be said of positive experiences, such as intervention to prevent or treat negative outcomes. In their annual review, Nelson et al. (2023) provide a timely and comprehensive review of how early intervention capitalizes on the neuroplasticity of the postnatal years, turning periods of 'vulnerability' to ones of 'opportunity'. Drawing on decades of expertise, they discuss the neurobiological mechanisms of intervention in two contexts: caregiving interventions for children growing up in disadvantaged environments, and therapeutic interventions for children at elevated risk of neurodevelopmental disorders such as Autism. They thought-provokingly describe both how early intervention operates through mechanisms of neural plasticity and how this can and should inform policy decisions to provide the greatest benefit to children. Here, I aim to underscore the importance of this review by addressing the intersection of these topics; specifically, I muse on how the scientific discovery of biological processes and the ethical imperative to support vulnerable children's development are intimately intertwined, and how this highlights both critical lines of future inquiry as well as policy implications.

Conversation disruptions in early childhood predict executive functioning development: A longitudinal study.

Conversational turn-taking is a complex communicative skill that requires both linguistic and executive functioning (EF) skills, including processing input while simultaneously forming and inhibiting responses until one's turn. Adult-child turn-taking predicts children's linguistic, cognitive, and socioemotional development. However, little is understood about how disruptions to temporal contingency in turn-taking, such as interruptions and overlapping speech, relate to cognitive outcomes, and how these relationships may vary across developmental contexts. In a longitudinal sample of 275 socioeconomically diverse mother-child dyads (children 50% male, 65% White), we conducted pre-registered examinations of whether the frequency of dyads' conversational disruption during free play when children were 3 years old related to children's executive functioning (EF; 9 months later), self-regulation skills (18 months later), and externalizing psychopathology in early adolescence (age 10-12 years). Contrary to hypotheses, more conversational disruptions significantly predicted higher inhibition skills, controlling for sex, age, income-to-needs (ITN), and language ability. Results were driven by maternal disruptions of the child's speech, and could not be explained by measures of overall talkativeness or interactiveness. Exploratory analyses revealed that ITN moderated these relationships, such that the positive effect of disruptions on inhibition was strongest for children from lower ITN backgrounds. We discuss how adult-driven "cooperative overlap" may serve as a form of engaged participation that supports cognition and behavior in certain cultural contexts.

Neurocognitive mechanisms of co-occurring math difficulties in dyslexia: Differences in executive function and visuospatial processing.

Children with dyslexia frequently also struggle with math. However, studies of reading disability (RD) rarely assess math skill, and the neurocognitive mechanisms underlying co-occurring reading and math disability (RD+MD) are not clear. The current study aimed to identify behavioral and neurocognitive factors associated with co-occurring MD among 86 children with RD. Within this sample, 43% had co-occurring RD+MD and 22% demonstrated a possible vulnerability in math, while 35% had no math difficulties (RD-Only). We investigated whether RD-Only and RD+MD students differed behaviorally in their phonological awareness, reading skills, or executive functions, as well as in the brain mechanisms underlying word reading and visuospatial working memory using functional magnetic resonance imaging (fMRI). The RD+MD group did not differ from RD-Only on behavioral or brain measures of phonological awareness related to speech or print. However, the RD+MD group demonstrated significantly worse working memory and processing speed performance than the RD-Only group. The RD+MD group also exhibited reduced brain activations for visuospatial working memory relative to RD-Only. Exploratory brain-behavior correlations along a broad spectrum of math ability revealed that stronger math skills were associated with greater activation in bilateral visual cortex. These converging neuro-behavioral findings suggest that poor executive functions in general, including differences in visuospatial working memory, are specifically associated with co-occurring MD in the context of RD. RESEARCH HIGHLIGHTS: Children with reading disabilities (RD) frequently have a co-occurring math disability (MD), but the mechanisms behind this high comorbidity are not well understood. We examined differences in phonological awareness, reading skills, and executive function between children with RD only versus co-occurring RD+MD using behavioral and fMRI measures. Children with RD only versus RD+MD did not differ in their phonological processing, either behaviorally or in the brain. RD+MD was associated with additional behavioral difficulties in working memory, and reduced visual cortex activation during a visuospatial working memory task.

The everyday speech environments of preschoolers with and without cochlear implants.

Children who receive cochlear implants develop spoken language on a protracted timescale. The home environment facilitates speech-language development, yet it is relatively unknown how the environment differs between children with cochlear implants and typical hearing. We matched eighteen preschoolers with implants (31-65 months) to two groups of children with typical hearing: by chronological age and hearing age. Each child completed a long-form, naturalistic audio recording of their home environment (appx. 16 hours/child; >730 hours of observation) to measure adult speech input, child vocal productivity, and caregiver-child interaction. Results showed that children with cochlear implants and typical hearing were exposed to and engaged in similar amounts of spoken language with caregivers. However, the home environment did not reflect developmental stages as closely for children with implants, or predict their speech outcomes as strongly. Home-based speech-language interventions should focus on the unique input-outcome relationships for this group of children with hearing loss.

Language development as a mechanism linking socioeconomic status to executive functioning development in preschool.

Childhood socioeconomic status (SES) is related to disparities in the development of both language and executive functioning (EF) skills. Emerging evidence suggests that language development may precede and provide necessary scaffolding for EF development in early childhood. The present preregistered study investigates how these skills co-develop longitudinally in early childhood and whether language development explains the relationship between SES and EF development. A socioeconomically diverse sample of 305 children completed repeated assessments of language (sentence comprehension) and EF (cognitive flexibility, behavioral inhibition, and cognitive inhibition) at four waves spaced 9 months apart from ages 3 to 5 years. Bivariate latent curve models with structured residuals were estimated to disaggregate between-person and within-person components of stability and change. Results revealed bidirectional relationships between language and EF across all waves. However, at 3 years, language comprehension more strongly predicted EF than the reverse; yet by 5 years, the bidirectional effects across domains did not significantly differ. Children from higher-SES backgrounds exhibited higher initial language and EF skills than children from lower-SES families, though SES was not associated with either rate of growth. Finally, early language-mediated the association between SES and early EF skills, and this model outperformed a reverse direction mediation. Together, results suggest that EF development is driven by early language development, and that SES disparities in EF are explained, at least in part, by early differences in language comprehension. These findings have implications for early interventions to support children's language skills as a potential pathway to improving early EF development.

Socioeconomic status and reading outcomes: Neurobiological and behavioral correlates.

In this chapter, we examine reading outcomes and socioeconomic status (SES) using a developmental cognitive and educational neuroscience perspective. Our focus is on reading achievement and intervention outcomes for students from lower SES backgrounds who struggle with reading. Socioeconomic disadvantage is a specific type of vulnerability students experience, which is often narrowly defined based on parental income, education level, and/or occupational prestige. However, implications of socioeconomic status extend broadly to a suite of areas relevant for reading outcomes including a student's access to resources, experiences, language exposure, academic outcomes, and psychological correlates. Underlying this constellation of factors are brain systems supporting the processing of oral and written language as well as stress-related factors. We review the implications of SES and reading achievement, and their intersectionality, for the science and practice of reading instruction.

Functional Territories of Human Dentate Nucleus.

Anatomical connections link the cerebellar cortex with multiple sensory, motor, association, and paralimbic cerebral areas. The majority of fibers that exit cerebellar cortex synapse in dentate nuclei (DN) before reaching extracerebellar structures such as cerebral cortex, but the functional neuroanatomy of human DN remains largely unmapped. Neuroimaging research has redefined broad categories of functional division in the human brain showing that primary processing, attentional (task positive) processing, and default-mode (task negative) processing are three central poles of neural macroscale functional organization. This broad spectrum of human neural processing categories is represented not only in the cerebral cortex, but also in the thalamus, striatum, and cerebellar cortex. Whether functional organization in DN obeys a similar set of macroscale divisions, and whether DN are yet another compartment of representation of a broad spectrum of human neural processing categories, remains unknown. Here, we show for the first time that human DN are optimally divided into three functional territories as indexed by high spatio-temporal resolution resting-state MRI in 77 healthy humans, and that these three distinct territories contribute uniquely to default-mode, salience-motor, and visual cerebral cortical networks. Our findings provide a systems neuroscience substrate for cerebellar output to influence multiple broad categories of neural control.

Reward-Sensitive Basal Ganglia Stabilize the Maintenance of Goal-Relevant Neural Patterns in Adolescents.

Maturation of basal ganglia (BG) and frontoparietal circuitry parallels developmental gains in working memory (WM). Neurobiological models posit that adult WM performance is enhanced by communication between reward-sensitive BG and frontoparietal regions, via increased stability in the maintenance of goal-relevant neural patterns. It is not known whether this reward-driven pattern stability mechanism may have a role in WM development. In 34 young adolescents (12.16-14.72 years old) undergoing fMRI, reward-sensitive BG regions were localized using an incentive processing task. WM-sensitive regions were localized using a delayed-response WM task. Functional connectivity analyses were used to examine the stability of goal-relevant functional connectivity patterns during WM delay periods between and within reward-sensitive BG and WM-sensitive frontoparietal regions. Analyses revealed that more stable goal-relevant connectivity patterns between reward-sensitive BG and WM-sensitive frontoparietal regions were associated with both greater adolescent age and WM ability. Computational lesion models also revealed that functional connections to WM-sensitive frontoparietal regions from reward-sensitive BG uniquely increased the stability of goal-relevant functional connectivity patterns within frontoparietal regions. Findings suggested (1) the extent to which goal-relevant communication patterns within reward-frontoparietal circuitry are maintained increases with adolescent development and WM ability and (2) communication from reward-sensitive BG to frontoparietal regions enhances the maintenance of goal-relevant neural patterns in adolescents' WM. The maturation of reward-driven stability of goal-relevant neural patterns may provide a putative mechanism for understanding the developmental enhancement of WM.

Longform recordings of everyday life: Ethics for best practices.

Recent advances in large-scale data storage and processing offer unprecedented opportunities for behavioral scientists to collect and analyze naturalistic data, including from underrepresented groups. Audio data, particularly real-world audio recordings, are of particular interest to behavioral scientists because they provide high-fidelity access to subtle aspects of daily life and social interactions. However, these methodological advances pose novel risks to research participants and communities. In this article, we outline the benefits and challenges associated with collecting, analyzing, and sharing multi-hour audio recording data. Guided by the principles of autonomy, privacy, beneficence, and justice, we propose a set of ethical guidelines for the use of longform audio recordings in behavioral research. This article is also accompanied by an Open Science Framework Ethics Repository that includes informed consent resources such as frequent participant concerns and sample consent forms.

Language Exposure Relates to Structural Neural Connectivity in Childhood.

Neuroscience research has elucidated broad relationships between socioeconomic status (SES) and young children's brain structure, but there is little mechanistic knowledge about specific environmental factors that are associated with specific variation in brain structure. One environmental factor, early language exposure, predicts children's linguistic and cognitive skills and later academic achievement, but how language exposure relates to neuroanatomy is unknown. By measuring the real-world language exposure of young children (ages 4-6 years, 27 male/13 female), we confirmed the preregistered hypothesis that greater adult-child conversational experience, independent of SES and the sheer amount of adult speech, is related to stronger, more coherent white matter connectivity in the left arcuate and superior longitudinal fasciculi on average, and specifically near their anterior termination at Broca's area in left inferior frontal cortex. Fractional anisotropy of significant tract subregions mediated the relationship between conversational turns and children's language skills and indicated a neuroanatomical mechanism underlying the SES "language gap." Post hoc whole-brain analyses revealed that language exposure was not related to any other white matter tracts, indicating the specificity of this relationship. Results suggest that the development of dorsal language tracts is environmentally influenced, specifically by early, dialogic interaction. Furthermore, these findings raise the possibility that early intervention programs aiming to ameliorate disadvantages in development due to family SES may focus on increasing children's conversational exposure to capitalize on the early neural plasticity underlying cognitive development.SIGNIFICANCE STATEMENT Over the last decade, cognitive neuroscience has highlighted the detrimental impact of disadvantaged backgrounds on young children's brain structure. However, to intervene effectively, we must know which proximal aspects of the environmental aspects are most strongly related to neural development. The present study finds that young children's real-world language exposure, and specifically the amount of adult-child conversation, correlates with the strength of connectivity in the left hemisphere white matter pathway connecting two canonical language regions, independent of socioeconomic status and the sheer volume of adult speech. These findings suggest that early intervention programs aiming to close the achievement gap may focus on increasing children's conversational exposure to capitalize on the early neural plasticity underlying cognitive development.

Socioeconomic Status and Reading Disability: Neuroanatomy and Plasticity in Response to Intervention.

Although reading disability (RD) and socioeconomic status (SES) are independently associated with variation in reading ability and brain structure/function, the joint influence of SES and RD on neuroanatomy and/or response to intervention is unknown. In total, 65 children with RD (ages 6-9) with diverse SES were assigned to an intensive, 6-week summer reading intervention (n = 40) or to a waiting-list control group (n = 25). Before and after, all children completed standardized reading assessments and magnetic resonance imaging to measure cortical thickness. At baseline, higher SES correlated with greater vocabulary and greater cortical thickness in bilateral perisylvian and supramarginal regions-especially in left pars opercularis. Within the intervention group, lower SES was associated with both greater reading improvement and greater cortical thickening across broad, bilateral occipitotemporal and temporoparietal regions following the intervention. Additionally, treatment responders (n = 20), compared with treatment nonresponders (n = 19), exhibited significantly greater cortical thickening within similar regions. The waiting control and nonresponder groups exhibited developmentally typical, nonsignificant cortical thinning during this time period. These findings indicate that effective summer reading intervention is coupled with cortical growth, and is especially beneficial for children with RD who come from lower-SES home environments.

Beyond the 30-Million-Word Gap: Children's Conversational Exposure Is Associated With Language-Related Brain Function.

Children's early language exposure impacts their later linguistic skills, cognitive abilities, and academic achievement, and large disparities in language exposure are associated with family socioeconomic status (SES). However, there is little evidence about the neural mechanisms underlying the relation between language experience and linguistic and cognitive development. Here, language experience was measured from home audio recordings of 36 SES-diverse 4- to 6-year-old children. During a story-listening functional MRI task, children who had experienced more conversational turns with adults-independently of SES, IQ, and adult-child utterances alone-exhibited greater left inferior frontal (Broca's area) activation, which significantly explained the relation between children's language exposure and verbal skill. This is the first evidence directly relating children's language environments with neural language processing, specifying both an environmental and a neural mechanism underlying SES disparities in children's language skills. Furthermore, results suggest that conversational experience impacts neural language processing over and above SES or the sheer quantity of words heard.

Do talkers produce less dispersed phoneme categories in a clear speaking style?

This study investigated whether adaptations made in clear speaking styles result in more discriminable phonetic categories than in a casual style. Multiple iterations of keywords with word-initial /s/-/ʃ/ were obtained from 40 adults in casual and clear speech via picture description. For centroids, cross-category distance increased in clear speech but with no change in within-category dispersion and no effect on discriminability. However, talkers produced fewer tokens with centroids in the ambiguous region for the /s/-/ʃ/ distinction. These results suggest that, whereas interlocutor feedback regarding communicative success may promote greater segmental adaptations, it is not necessary for some adaptation to occur.

Precision fMRI reveals that the language network exhibits adult-like left-hemispheric lateralization by 4 years of age.

Left hemisphere damage in adulthood often leads to linguistic deficits, but many cases of early damage leave linguistic processing preserved, and a functional language system can develop in the right hemisphere. To explain this early apparent equipotentiality of the two hemispheres for language, some have proposed that the language system is bilateral during early development and only becomes left-lateralized with age. We examined language lateralization using functional magnetic resonance imaging with two large pediatric cohorts (total n=273 children ages 4-16; n=107 adults). Strong, adult-level left-hemispheric lateralization (in activation volume and response magnitude) was evident by age 4. Thus, although the right hemisphere can take over language function in some cases of early brain damage, and although some features of the language system do show protracted development (magnitude of language response and strength of inter-regional correlations in the language network), the left-hemisphere bias for language is robustly present by 4 years of age. These results call for alternative accounts of early equipotentiality of the two hemispheres for language.

Dynamic functional connectivity correlates of trait mindfulness in early adolescence.

Background: Trait mindfulness, the tendency to attend to present-moment experiences without judgement, is negatively correlated with adolescent anxiety and depression. Understanding the neural mechanisms underlying trait mindfulness may inform the neural basis of psychiatric disorders. However, few studies have identified brain connectivity states that correlate with trait mindfulness in adolescence, nor have they assessed the reliability of such states. Methods: To address this gap in knowledge, we rigorously assessed the reliability of brain states across 2 functional magnetic resonance imaging (fMRI) scan from 106 adolescents aged 12 to 15 (50% female). We performed both static and dynamic functional connectivity analyses and evaluated the test-retest reliability of how much time adolescents spent in each state. For the reliable states, we assessed associations with self-reported trait mindfulness. Results: Higher trait mindfulness correlated with lower anxiety and depression symptoms. Static functional connectivity (ICCs from 0.31-0.53) was unrelated to trait mindfulness. Among the dynamic brains states we identified, most were unreliable within individuals across scans. However, one state, an hyperconnected state of elevated positive connectivity between networks, showed good reliability (ICC=0.65). We found that the amount of time that adolescents spent in this hyperconnected state positively correlated with trait mindfulness. Conclusions: By applying dynamic functional connectivity analysis on over 100 resting-state fMRI scans, we identified a highly reliable brain state that correlated with trait mindfulness. The brain state may reflect a state of mindfulness, or awareness and arousal more generally, which may be more pronounced in those who are higher in trait mindfulness.

Digital Media and Developing Brains: Concerns and Opportunities.

Purpose of Review: The incorporation of digital technologies and their use in youth's everyday lives has been increasing rapidly over the past several decades with possible impacts on youth development and mental health. This narrative review aimed to consider how the use of digital technologies may be influencing brain development underlying adaptive and maladaptive screen-related behaviors. Recent Findings: To explore and provide direction for further scientific inquiry, an international group of experts considered what is known, important gaps in knowledge, and how a research agenda might be pursued regarding relationships between screen media activity and neurodevelopment from infancy through childhood and adolescence. While an understanding of brain-behavior relationships involving screen media activity has been emerging, significant gaps exist that have important implications for the health of developing youth. Summary: Specific considerations regarding brain-behavior relationships involving screen media activity exist for infancy, toddlerhood, and early childhood; middle childhood; and adolescence. Transdiagnostic frameworks may provide a foundation for guiding future research efforts. Translating knowledge gained into better interventions and policy to promote healthy development is important in a rapidly changing digital technology environment.

Developmental and gender-related trends of intra-talker variability in consonant production.

This study investigates the effect of age and gender on the internal structure, cross-category distance, and discriminability of phonemic categories for two contrasts varying in fricative place of articulation (/s/-/∫/) and stop voicing (/b/-/p/) in word-initial tokens spoken by adults and normally developing children aged 9-14 yr. Vast between- and within-talker variability was observed with 16% of speakers exhibiting some degree of overlap between phonemic categories-a possible contribution to the range of talker intelligibility found in the literature. Females of all ages produced farther and thus more discriminable categories than males, although gender-marking for fricative between-category distance did not emerge until approximately 11 yr of age. Children produced farther yet also much more dispersed categories than adults with increasing discriminability with age, such that by age 13, children's categories were no less discriminable than those of adults. However, children's ages did not predict category distance or dispersion, indicating that convergence on adult-like category structure must occur later in adolescence.

Socioeconomic Status and Reading Development: Moving from "Deficit" to "Adaptation" in Neurobiological Models of Experience-Dependent Learning.

Childhood socioeconomic status (SES) is one of the strongest predictors of student reading outcomes, and these disparities have persisted for decades. Relatedly, two underlying skills that are required for successful reading-oral language and executive function (EF)-are also the two neurocognitive domains most affected by SES. In this review, we summarize current knowledge on how SES influences the neurobiology of language, EF, and their intersection, including the proximal factors that drive these relationships. We then consider the burgeoning evidence that SES systematically moderates certain brain-behavior relationships for language and EF, underscoring the importance of considering context in investigations of the neurobiological underpinnings of reading development. Finally, we discuss how disparities in reading may be conceptualized as neurobiological adaptations to adversity rather than deficit models. We conclude by suggesting that by harnessing children's stress-adapted relative strengths to support reading development, we may address opportunity gaps both ethically and efficaciously.

Parent and staff perspectives on the benefits and barriers to communication with infants in the neonatal intensive care unit.

Exposure to high quantity and quality of language in the neonatal period is critical to neurocognitive development; however, Neonatal Intensive Care Unit (NICU) environments may contribute to language deprivation. Using qualitative thematic content analysis, this study aimed to characterize the knowledge and attitudes of NICU staff and patient families toward the importance of early language experience, the current NICU language environment, and the benefits and barriers of communication in the NICU. Results revealed that all respondents recognized the importance of communication for optimal cognitive development, though few understood why. Staff and family members alike recognized the role of nurses as coaches and role models in promoting communication at the bedside. Nurses generally felt that family members communicate less with their babies than family members themselves perceived, and that cell phone use has fewer communicative advantages than parents perceive. Respondents reported that patient illness, lack of time, and intimidating equipment all raise barriers to communication. These findings yield important considerations for developing educational interventions to improve NICU language environments, including a synergistic, dual focus on both staff and families. Communication in the NICU is a low cost, feasible, and accessible target with aims of ensuring optimal neurocognitive development for at-risk children.