Neuroscience of Childhood Poverty: Evidence of Impacts and Mechanisms as Vehicles of Dialog With Ethics

Epigenetic mechanisms linking early-life adversities and mental health

Early-life adversities, whether prenatal or postnatal exposure, have been linked to adverse mental health outcomes later in life increasing the risk of several psychiatric disorders. Research on its neurobiological consequences demonstrated an association between exposure to adversities and persistent alterations in the structure, function, and connectivity of the brain. Consistent evidence supports the idea that regulation of gene expression through epigenetic mechanisms are involved in embedding the impact of early-life experiences in the genome and mediate between social environments and later behavioral phenotypes. In addition, studies from rodent models and humans suggest that these experiences and the acquired risk factors can be transmitted through epigenetic mechanisms to offspring and the following generations potentially contributing to a cycle of disease or disease risk. However, one of the important aspects of epigenetic mechanisms, unlike genetic sequences that are fixed and unchangeable, is that although the epigenetic markings are long-lasting, they are nevertheless potentially reversible. In this review, we summarize our current understanding of the epigenetic mechanisms involved in the mental health consequences derived from early-life exposure to malnutrition, maltreatment and poverty, adversities with huge and pervasive impact on mental health. We also discuss the evidence about transgenerational epigenetic inheritance in mammals and experimental data suggesting that suitable social and pharmacological interventions could reverse adverse epigenetic modifications induced by early-life negative social experiences. In this regard, these studies must be accompanied by efforts to determine the causes that promote these adversities and that result in health inequity in the population.

Translational Neuroethics: A Vision for a More Integrated, Inclusive, and Impactful Field

As early-career neuroethicists, we come to the field of neuroethics at a unique moment: we are well-situated to consider nearly two decades of neuroethics scholarship and identify challenges that have persisted across time. But we are also looking squarely ahead, embarking on the next generation of exciting and productive neuroethics scholarship. In this article, we both reflect backwards and turn our gaze forward. First, we highlight criticisms of neuroethics, both from scholars within the field and outside it, that have focused on speculation and lack of skepticism; the dearth of consideration of broader social issues such as justice and equality, both with regard to who speaks for neuroethics as a field and who benefits from its recommendations and findings; and the insufficient focus on the practical impact of our ethical work. Second, we embrace the concept of "translational neuroethics" to outline a vision for neuroethics that is integrated, inclusive, and impactful. Integration can help us identify more pertinent, real-world issues, and move away from speculation; inclusivity can help ensure that the questions we attend to are not merely relevant to a single subgroup but aim toward just distribution of benefits; and impact can help us think beyond guidelines and recommendations to focus on implementation. Our goal is for this call to action to help shape neuroethics into a discipline that develops rigorous research agendas through relationships with interdisciplinary partners, that is broadly inclusive and attends to issues beyond novel neurotechnologies, and that is devoted to the translation of scholarship into practice.

Predicting Effortful Control at 3 Years of Age from Measures of Attention and Home Environment in Infancy: A Machine Learning Approach

Effortful control (EC) is a dimension of temperament that encompass individual differences in self-regulation and the control of reactivity. Much research suggests that EC has a strong foundation on the development of executive attention, but increasing evidence also shows a significant contribution of the rearing environment to individual differences in EC. The aim of the current study was to predict the development of EC at 36 months of age from early attentional and environmental measures taken in infancy using a machine learning approach. A sample of 78 infants participated in a longitudinal study running three waves of data collection at 6, 9, and 36 months of age. Attentional tasks were administered at 6 months of age, with two additional measures (i.e., one attentional measure and another self-restraint measure) being collected at 9 months of age. Parents reported household environment variables during wave 1, and their child's EC at 36 months. A machine-learning algorithm was implemented to identify children with low EC scores at 36 months of age. An "attention only" model showed greater predictive sensitivity than the "environmental only" model. However, a model including both attentional and environmental variables was able to classify the groups (Low-EC vs. Average-to-High EC) with 100% accuracy. Sensitivity analyses indicate that socio-economic variables together with attention control processes at 6 months, and self-restraint capacity at 9 months, are the most important predictors of EC. Results suggest a foundational role of executive attention processes in the development of EC in complex interactions with household environments and provide a new tool to identify early markers of socio-emotional regulation development.

Brain morphometry and diminished physical growth in Bangladeshi children growing up in extreme poverty: A longitudinal study

Diminished physical growth is a common marker of malnutrition and it affects approximately 200 million children worldwide. Despite its importance and prevalence, it is not clear whether diminished growth relates to brain development and general cognitive ability. Further, diminished growth is more common in areas of extreme poverty, raising the possibility that it may mediate previously shown links between socioeconomic status (SES) and brain structure. To address these gaps, 79 children growing up in an extremely poor, urban area of Bangladesh underwent MRI at age six years. Structural brain images were submitted to Mindboggle software, a Docker-compliant and high-reproducibility tool for tissue segmentation and regional estimations of volume, surface area, cortical thickness, sulcal depth, and mean curvature. Diminished growth predicted brain morphometry and mediated the link between SES and brain morphometry most consistently for subcortical and white matter subcortical volumes. Meanwhile, brain volume in left pallidum and right ventral diencephalon mediated the relationship between diminished growth and full-scale IQ. These findings offer malnutrition as one possible pathway through which SES affects brain development and general cognitive ability in areas of extreme poverty.

Association between poverty exposure during childhood and adolescence, and drug use disorders and drug-related crimes later in life

AIMS

To examine whether poverty exposure in childhood/adolescence increases the risk of later drug use disorder and drug crime conviction.

DESIGN, SETTING AND PARTICIPANTS

A national cohort study encompassing 634 284 individuals born between 1985 and 1990, residing in Sweden between 5 and 18 years of age, followed-up from January 2004 to December 2016, starting from the age of 19 years until the first visit to inpatient/outpatient care with a diagnosis of a drug use disorder or a drug crime offence.

MEASUREMENTS

The exposure variable was 'trajectories of poverty' based on household income, assessed through group-based trajectory analysis. Cox regression analysis was used to obtain hazard ratios for drug use disorders and drug crime convictions using age as the underlying time scale.

FINDINGS

We identified five trajectories of childhood/adolescence poverty: (1) 'moving out of poverty in childhood' (8.7%); (2) 'never poverty' (68.9%); (3) 'moving into poverty in adolescence' (11.0%); (4) 'moving out of poverty in adolescence' (5.4%); and (5) 'chronically poor' (5.9%). Compared with the 'never poor' group, almost all trajectory groups had higher risks for drug use problems. Young males 'moving into poverty in adolescence' had the highest risks of drug use disorder [hazard ratio (HR) = 1.48, 95% confidence interval (CI) = 1.40-1.57] and drug crime conviction (HR = 1.50, 95% CI = 1.38-1.62), after adjusting for calendar year, domicile, origin, psychiatric diagnosis and parental psychiatric diagnosis. The results were similar in females moving into poverty in adolescence (HR = 1.63, 95% CI = 1.52-1.76 and HR = 1.89, 95% CI = 1.74-2.05 for drug use disorders and drug crime, respectively).

CONCLUSION

In Sweden, poverty exposure early in life seems to increase the risk of drug use problems in adulthood. These associations are not explained fully by domicile, origin or other psychiatric disorders. Young males and females moving into poverty in adolescence are at highest risk.

Of Ethical Frameworks and Neuroethics in Big Neuroscience Projects: A View from the HBP

The recently published BRAIN 2.0 Neuroethics Report offers a very helpful overview of the possible ethical, social, philosophical, and legal issues raised by neuroscience in the context of BRAIN's research priorities thus contributing to the attempt to develop ethically sound neuroscience. In this article, we turn to a running theme of the document: the need for an ethical framework for the BRAIN Initiative and for further integration of neuroethics and neuroscience. We assess some of the issues raised and provide an explanation of how we have addressed them in the Human Brain Project. We offer our experience in the HBP as a potential contribution to the international debate about neuroethics in the big brain initiatives. Our hope is that among other things, the type of exchange proposed by this AJOB special issue will prove productive in further identifying and discussing the issues and in inspiring appropriate solutions.

Evidence for dissociable cognitive and neural pathways from poverty versus maltreatment to deficits in emotion regulation

Poverty and threat exposure (TE) predict deficits in emotion regulation (ER). Effective cognitive ER (i.e., reappraisal) may be supported by: (1) cognitive processes implicated in generating and implementing cognitive reappraisal, supported by activation in brain regions involved in cognitive control (e.g., frontal, insular, and parietal cortices) and (2) emotion processing and reactivity, involving identification, encoding, and maintenance of emotional states and related variation in brain activity of regions involved in emotional reactivity (i.e., amygdala). Poverty is associated with deficits in cognitive control, and TE with alterations in emotion processing and reactivity. Our goal was to identify dissociable emotional and cognitive pathways to ER deficits from poverty and TE. Measures of cognitive ability, emotional processing and reactivity, ER, and neural activity during a sadness ER task, were examined from a prospective longitudinal study of youth at risk for depression (n = 139). Both cognitive ability and left anterior insula extending into the frontal operculum activity during a sadness reappraisal task mediated the relationship between poverty and ER. Emotion processing/reactivity didn’t mediate the relationship of TE to ER. Findings support a cognitive pathway from poverty to ER deficits. They also underscore the importance of dissociating mechanisms contributing to ER impairments from adverse early childhood experiences.

Far and wide: Associations between childhood socio-economic status and brain connectomics

Previous studies have identified localized associations between childhood environment - namely their socio-economic status (SES) - and particular neural structures. The primary aim of the current study was to test whether associations between SES and brain structure are widespread or limited to specific neural pathways. We employed advances in whole-brain structural connectomics to address this. Diffusion tensor imaging was used to construct whole-brain connectomes in 113 6-12 year olds. We then applied an adapted multi-block partial-least squares (PLS) regression to explore how connectome organisation is associated with childhood SES (parental income, education levels, and neighbourhood deprivation). The Fractional Anisotropy (FA) connectome was significantly associated with childhood SES and this effect was widespread. We then pursued a secondary aim, and demonstrated that the connectome mediated the relationship between SES and cognitive ability (matrix reasoning and vocabulary). However, the connectome did not significantly mediate SES relationships with academic ability (maths and reading) or internalising and externalising behavior. This multivariate approach is important for advancing our theoretical understanding of how brain development may be shaped by childhood environment, and the role that it plays in predicting key outcomes. We also discuss the limitations with this new methodological approach.

Development of executive functions in Lebanese children

The current study focused on adapting EF tests for children to the Arabic language and examine the developmental trajectories of a sample of school-aged Lebanese children in four domains of EF (inhibition, flexibility, working memory, and planning). It also focused on examining the effects of gender and parental education level on EF performance. The study population included 100 Lebanese children aged from 6 to 12-years old who were grouped and comparable for age, gender, and parental level of education. Results revealed a main effect of age and level of education of parents while the effect of gender was non-significant.

Well-Designed Food Governance as Psychological Mechanism of Consumer Perceptions in the Context of Tourism Poverty Alleviation

Poverty is a challenge leading to food insecurity in people's minds. This article discusses food governance as a psychological mechanism to facilitate the sense of wellness in people's minds in the context of tourism poverty alleviation. Mainly, we argue that, when a government is implementing tourism poverty alleviation, not only are economic efforts, but also positive psychological feelings are required. We, thus, argue that sound food governance may increase the sense of wellness in the minds of people as food consumers by increasing food safety and security. This perspective paper contributes by explicating the influences of macrolevel governance design of safer and more secure food systems on people's psychological wellness, especially against the background of tourism poverty alleviation in developing countries.

Rethinking Concepts and Categories for Understanding the Neurodevelopmental Effects of Childhood Adversity

Discovering the processes through which early adverse experiences affect children’s nervous-system development, health, and behavior is critically important for developing effective interventions. However, advances in our understanding of these processes have been constrained by conceptualizations that rely on categories of adversity that are overlapping, have vague boundaries, and lack consistent biological evidence. Here, we discuss central problems in understanding the link between early-life adversity and children’s brain development. We conclude by suggesting alternative formulations that hold promise for advancing knowledge about the neurobiological mechanisms through which adversity affects human development.

Socioeconomic status and the brain: prospects for neuroscience-informed policy

Socioeconomic status (SES) is associated with health (physical and mental) and cognitive ability. Understanding and ameliorating the problems of low SES have long been goals of economics and sociology; in recent years, these have also become goals of neuroscience. However, opinion varies widely on the relevance of neuroscience to SES-related policy. The present article addresses the question of whether and how neuroscience can contribute to the development of social policy concerning poverty and the social and ethical risks inherent in trying. I argue that the neuroscience approach to SES-related policy has been both prematurely celebrated and peremptorily dismissed and that some of its possible social impacts have been viewed with excessive alarm. Neuroscience has already made modest contributions to SES-related policy, and its potential to have a more effective and beneficial influence can be expected to grow over the coming years.

Childhood Brain Development, the Educational Achievement Gap, and Cognitive Enhancement

Research on the effects of adversity on the brain of children initially encountered strong skepticism mainly due to the fear of stigmatization and the potential pathologizing of poverty as a disease. Despite initial resistance, an increasing body of work demonstrates a correlation between low socioeconomic status and brain development. This article will focus specifically on the impact of poverty (material, economic, and social) on childhood brain development and educational achievement. Some suggest that the use of cognitive enhancers in healthy students is perfectly acceptable and should be promoted to counterbalance the failure of traditional means to improve educational achievements. In this article, I critically assess the claim that a broad use of cognitive enhancers should be promoted and offer an alternative approach. The first section evaluates the neuroscientific facts and evidence of the impact of poverty on brain development and outlines some of the criticisms raised against the “neuroscience of poverty.” The second section focuses on the proposal made by Ray (2016) that promotes the use of cognitive enhancers as a means to address poor educational attainment. I criticize the basis of her argument and propose a different approach I call the clinical ideal. Subsequently, I provide some ethical pointers to allow an ethical and prudent use of cognitive enhancers in the educational setting. The main point of the article is not to reject prima facie the use of cognitive enhancers in socially disadvantaged students but rather provide a more nuanced approach.

Developmental trajectories of children with Down syndrome by socio-economic status: the case of Latin America

BACKGROUND

Several studies show that socio-economic status (SES) is related to the developmental trajectories of children with typical development (TD). However, few studies have analysed this relationship regarding children with neurodevelopmental disorders such as Down syndrome (DS). In this paper, we analyse the impact of SES in the neurodevelopmental trajectories of children with DS in comparison with children with TD.

METHOD

Cognitive, language, motor and socio-emotional development were assessed in 31 children with DS between the ages of 15 and 80 months from high to low SES backgrounds. Data from this group were compared with data from a sample of 72 children with TD randomly selected from the Longitudinal Survey of Early Childhood. We analyse and compare these two groups using the developmental trajectories method RESULTS: The results show delayed onsets for the four abilities measured in children with DS compared with children with TD from high to low SES. In the comparison of the developmental trajectories, we found that the differences between the neurodevelopmental trajectories in DS and TD vary according to SES. High SES show differences only in language development, while low SES show significant differences in cognitive, language and socio-emotional development.

CONCLUSIONS

The results indicate that SES is a factor that could impact the developmental trajectories of children with DS. Although the differences between children with DS and with TD are similar at the beginning regardless of SES, the developmental trajectories are slower in children with DS of low SES than in children of high SES. We argue that the differences are related to the complex interaction of several biological and cultural factors associated with SES. Some specific hypotheses about nutrition, health care access, quality of education and parenting practices are presented, but more research in this area is needed to fully understand these results.

Attending, learning, and socioeconomic disadvantage: developmental cognitive and social neuroscience of resilience and vulnerability

We review current findings associating socioeconomic status (SES), development of neurocognitive functions, and neurobiological pathways. A sizeable interdisciplinary literature was organized through a bifurcated developmental trajectory (BiDeT) framework, an account of the external and internal variables associated with low SES that may lead to difficulties with attention and learning, along with buffers that may protect against negative outcomes. A consistent neurocognitive finding is that low-SES children attend to information nonselectively, and engage in late filtering out of task-irrelevant information. Attentional preferences influence the development of latent inhibition (LI), an aspect of learning that involves reassigning meaningful associations to previously learned but irrelevant stimuli. LI reflects learning processes clarifying the relationship between neurobiological mechanisms related to attention and socioeconomic disadvantage during child development. Notably, changes in both selective attention and typical LI development may occur via the mesocorticolimbic dopamine (MsCL-DA) system. Chaotic environments, social isolation, and deprivation associated with low SES trigger stress responses implicating imbalances in the MsCL-DA and consolidating anxiety traits. BiDeT describes plausible interactions between socioemotional traits and low-SES environments that modify selective attention and LI, predisposing individuals to vulnerability in cognitive development and academic achievement. However, positive role models, parental style, and self-regulation training are proposed as potential promoters of resilience.