Emily C. Merz

Age-Related Differences in Cortical Thickness Vary by Socioeconomic Status

Recent findings indicate robust associations between socioeconomic status (SES) and brain structure in children, raising questions about the ways in which SES may modify structural brain development. In general, cortical thickness and surface area develop in nonlinear patterns across childhood and adolescence, with developmental patterns varying to some degree by cortical region. Here, we examined whether age-related nonlinear changes in cortical thickness and surface area varied by SES, as indexed by family income and parental education. We hypothesized that SES disparities in age-related change may be particularly evident for language- and literacy-supporting cortical regions. Participants were 1148 typically-developing individuals between 3 and 20 years of age. Results indicated that SES factors moderate patterns of age-associated change in cortical thickness but not surface area. Specifically, at lower levels of SES, associations between age and cortical thickness were curvilinear, with relatively steep age-related decreases in cortical thickness earlier in childhood, and subsequent leveling off during adolescence. In contrast, at high levels of SES, associations between age and cortical thickness were linear, with consistent reductions across the age range studied. Notably, this interaction was prominent in the left fusiform gyrus, a region that is critical for reading development. In a similar pattern, SES factors significantly moderated linear age-related change in left superior temporal gyrus, such that higher SES was linked with steeper age-related decreases in cortical thickness in this region. These findings suggest that SES may moderate patterns of age-related cortical thinning, especially in language- and literacy-supporting cortical regions.

Parenting Predictors of Cognitive Skills and Emotion Knowledge in Socioeconomically Disadvantaged Preschoolers

This study examined the concurrent and longitudinal associations of parental responsiveness and inferential language input with cognitive skills and emotion knowledge among socioeconomically disadvantaged preschoolers. Parents and 2- to 4-year-old children (mean age=3.21 years, N=284) participated in a parent-child free play session, and children completed cognitive (language, early literacy, early mathematics) and emotion knowledge assessments. Approximately 1 year later, children completed the same assessment battery. Parental responsiveness was coded from the videotaped parent-child free play sessions, and parental inferential language input was coded from transcripts of a subset of 127 of these sessions. All analyses controlled for child age, gender, and parental education, and longitudinal analyses controlled for initial skill level. Parental responsiveness significantly predicted all concurrent cognitive skills as well as literacy, math, and emotion knowledge 1 year later. Parental inferential language input was significantly positively associated with childrens concurrent emotion knowledge. In longitudinal analyses, an interaction was found such that for children with stronger initial language skills, higher levels of parental inferential language input facilitated greater vocabulary development, whereas for children with weaker initial language skills, there was no association between parental inferential language input and change in childrens vocabulary skills. These findings further our understanding of the roles of parental responsiveness and inferential language input in promoting childrens school readiness skills.

Bidirectional Associations Between Parental Responsiveness and Executive Function During Early Childhood

In this study, we examined bidirectional associations between parental responsiveness and executive function (EF) processes in socioeconomically disadvantaged preschoolers. Participants were 534 3- to 5-year-old children (71% Hispanic/Latino; 28% African American; 1% European American) attending Head Start programs. At Time 1 (T1) and 6.5 months later at Time 2 (T2), parents and children participated in a videotaped free play session and children completed delay inhibition (gift delay-wrap, gift delay-bow) and conflict EF (bear/dragon, dimensional change card sort) tasks. Parental warm acceptance, contingent responsiveness, and verbal scaffolding were coded from the free play videos and aggregated to create a parental responsiveness latent variable. A cross-lagged panel structural equation model indicated that higher T1 parental responsiveness significantly predicted more positive gain in delay inhibition and conflict EF from T1 to T2. Higher T1 delay inhibition, but not T1 conflict EF, significantly predicted more positive change in parental responsiveness from T1 to T2. These associations were not explained by several possible confounding variables, including childrens age, gender, race/ethnicity, and verbal ability. Findings suggest that parental responsiveness may support EF development in disadvantaged children, with reciprocal effects of delay inhibition on parental responsiveness.

Attention and language as mediators of academic outcomes following early psychosocial deprivation

Children adopted from institutions at older ages are at increased risk of persistent attention problems, lower cognition, and academic difficulties. This study examined cognitive and behavior problems as mediators of the association between early psychosocial deprivation and academic functioning. Participants were 8–17-year-old children adopted from psychosocially-depriving Russian institutions after 14 months of age (n = 34) and before 9 months of age (n = 39). Children completed a cognitive assessment, while their parents completed questionnaires on child behavior problems and use of learning support services in school. Children adopted after 14 months were found to have significantly lower vocabulary, higher levels of attention problems, and higher rates of using learning support services relative to children adopted before 9 months after controlling for age at assessment. The two groups did not differ significantly in nonverbal reasoning, anxiety, or oppositional behavior. Attention and vocabulary significantly mediated the association of early psychosocial deprivation with the use of learning support services. These findings suggest that interventions targeting attention regulatory and language skills may be beneficial in terms of improving school performance in this population.

Anxiety, depression, impulsivity, and brain structure in children and adolescents

The unique neuroanatomical underpinnings of internalizing symptoms and impulsivity during childhood are not well understood. In this study, we examined associations of brain structure with anxiety, depression, and impulsivity in children and adolescents. Participants were 7- to 21-year-olds (N = 328) from the Pediatric Imaging, Neurocognition, and Genetics (PING) study who completed high-resolution, 3-Tesla, T1-weighted MRI and self-report measures of anxiety, depression, and/or impulsivity. Cortical thickness and surface area were examined across cortical regions-of-interest (ROIs), and exploratory whole-brain analyses were also conducted. Gray matter volume (GMV) was examined in subcortical ROIs. When considered separately, higher depressive symptoms and impulsivity were each significantly associated with reduced cortical thickness in ventromedial PFC/medial OFC, but when considered simultaneously, only depressive symptoms remained significant. Higher impulsivity, but not depressive symptoms, was associated with reduced cortical thickness in the frontal pole, rostral middle frontal gyrus, and pars orbitalis. No differences were found for regional surface area. Higher depressive symptoms, but not impulsivity, were significantly associated with smaller hippocampal GMV and larger pallidal GMV. There were no significant associations between anxiety symptoms and brain structure. Depressive symptoms and impulsivity may be linked with cortical thinning in overlapping and distinct regions during childhood and adolescence.

Parent Involvement in the Getting Ready for School Intervention Is Associated With Changes in School Readiness Skills

The role of parent involvement in school readiness interventions is not well-understood. The Getting Ready for School (GRS) intervention is a novel program that has both home and school components and aims to improve early literacy, math, and self-regulatory skills in preschool children from socioeconomically disadvantaged families. In this study, we first examined associations between family characteristics and different indices of parent involvement in the GRS intervention. We then examined associations between parent involvement and change in childrens school readiness skills over time. Participants were 133 preschool children attending Head Start and their parents who participated in the GRS intervention during the academic year 2014–2015. Parent involvement was operationalized as attendance to GRS events at the school, time spent at home doing GRS activities, and usage of digital program materials, which included a set of videos to support the implementation of parent-child activities at home. Although few family characteristics were significantly associated with parent involvement indices, there was a tendency for some markers of higher socioeconomic status to be linked with greater parent involvement. In addition, greater parent involvement in the GRS intervention was significantly associated with greater gains in childrens early literacy, math, and self-regulatory skills. These findings suggest that parent involvement in comprehensive early interventions could be beneficial in terms of improving school readiness for preschoolers from disadvantaged families.

School climate is associated with cortical thickness and executive function in children and adolescents

A positive school climate has been found to support mental and physical health, academic achievement and social adjustment among youth. However, links between school climate and brain structure have not been investigated to date. In this study, we investigated whether school climate was associated with executive function (EF) and brain structure (cortical thickness and surface area) in children and adolescents. We further examined whether these links varied as a function of socioeconomic background. Participants who ranged from 9 to 18 years of age (N = 108) completed EF tasks and a high-resolution, 3-Tesla, T1-weighted magnetic resonance imaging (MRI) scan. Overall school climate, academic support, and family socioeconomic background were assessed using questionnaires. Higher academic support was associated with greater EF task performance and increased global cortical thickness. Additionally, academic support moderated the association between family income and EF, such that children from lower income families performed similarly to their more advantaged peers on EF tasks in the context of positive academic support. This work is the first to link school climate to brain structure and contributes to the growing body of evidence suggesting that academic support may be an important protective factor in the context of socioeconomic disadvantage.