Article summary with Poverty and self-regulation: Connecting psychosocial processes, neurobiology, and the risk for psychopathology by Palacios-Barrios & Hanson - 2019

How is poverty related to negative mental health outcomes?

Poverty is marked by economic, social, and psychological challenges. It is associated with many different stressors and disadvantages, such as issues with household noise, structure, and organization, higher rates of community violence, exposure to teratogens, differences in cognitively stimulating experiences, and inferior perceptions of the self. Research has shown that exposure to poverty in childhood is associated with increases in externalizing and internalizing problems, and that the effects of child poverty persist into adulthood.

How can neuroscience be used to understand the mechanism relating poverty to negative mental health outcomes?

Nearly any form of psychopathology represents the integrated output of multiple underlying neural systems. As the brain is especially shaped by early life experiences, it ultimately determines behavioral and physiological responses over the course of the lifespan. Research points to the important role of self-regulation as a mediator between child poverty and psychopathology. Self-regulation is important for development and may aid in integratively organizing neural circuits central to its components, such as attentional focus and emotion regulation.

What is self-regulation?

Self-regulation can be defined as the ability to adaptively modulate one´s own cognitions, emotions, and actions for the purposes of goal-director behavior. It can be separated in two categories:

• Bottom-up mechanisms involve responses that are automatic and reactive. The two bottom-up facets that are identified (and their connected central neural hubs) are salience evaluation and interpretation (amygdala and ventral striatum), and stimulus generalization (hippocampus).
• Top-down processes refer to deliberate and controlled thoughts or actions that are used to problem-solve, resolve conflict, or prepare for an expected objective. The two top-down elements of self-regulation that are distinguished (and their connected central neural hubs) are executive attention (dorsal anterior cingulate cortex, dorsolaterale prefrontal cortex, insula), and response evaluation and emotion modulation (ventromedial prefrontal cortex and lateral prefrontal cortex).

What are common neuroscientific research methods?

Each measure has different strengths and limitations:

• Magnetic resonance imaging (MRI) produces spatially rich images of brain anatomy where the volumes of regions are measured. It does not provide information about brain activity. Regions may differ in volumes but be more or less active during a cognitive process.
• Diffusion-weighted imaging (DWI) is a type of MRI that probes structural connectivity in the brain through assessment of water diffusion in brain white matter. It does not measure brain functioning.
• Fractional anisotropy (FA) is a derived measure in DWI and describes the directionality of water diffusion and is modulated by microstructural properties of white matter, including fiber density, myelination, and axonal diameter. More diffuse white matter connections, lower axonal density, or reduced myelination may impede brain functioning.
• Electroencephalography (EEG) measures electrical activity on the head that is partially reflective of activity of neurons and the brain´s other basic machinery. It offers very precise temporal resolution, but poor spatial resolution.
• Functional MRI (fMRI) measures differences in blood oxygenation, which is highly correlated with actual neuronal activity. It offers high spatial resolution, but does not clarify the specific timing of the events occurring in the brain.

What is executive attention and how is it associated with childhood poverty?

Executive attention can be viewed as the broad, top-down ability to hold and use stable representations to guide behavior, while also adapting to and incorporating important incoming information. Two brain networks act relatively independently to produce top-down control, namely the fronto-parietal network and the cingulo-opercular network. Lower socioeconomic status has been associated with worse executive functioning, including differences in attention shifting, working memory, and inhibition. Young people living in poverty show structural differences in the fronto-parietal and cingulo-opercular attention networks.

What is value-based decision-making and how does it relate to childhood poverty?

Value-based decision-making is a method for making critical organizational decisions in an informed and timely manner. If a person decides to pursue a goal, they may consider both the perceived value and costs of the goal. These subjective elements determine the behaviors pursued. The ventro-medial prefrontal cortex (vmPFC) appears to be involved in value-based decision-making. Childhood poverty is found to be linked to smaller vmPFC volumes, and lower structural and functional connectivity between the vmPFC and other brain regions. This impairment may mean that disadvantaged youth may be less effective when making value-based decisions.

What is salience evaluation and interpretation?

Salience evaluation and interpretation refers to reward and vigilance processing. The subcortical structure ventral striatum (VS) is critical to incentive motivation. It displays higher activity depending on different dimensions of reward, including magnitude, effort, probability, and delay. Research has found an association between higher levels of VS activity during different reward paradigms and a preference for smaller immediate rewards. There is also evidence of alterations in functional connectivity in the broader circuit that the VS is nested in, which may connect to aberrant use of reward signals to guide behavior.

How is the hippocampus related to poverty?

The hippocampus plays an important role in consolidating information from short-term memory to long-term memory, which may impact self-regulation. Research has linked child poverty to deviations in the function of the hippocampus at all stages of development, particularly, young people from low socioeconomic background appear to have smaller hippocampal volumes. These differences may be due to the hypothalamic-pituitary-adrenal axis (HPA-axis) and cortisol. Sustained elevated HPA axis activity may cause dendritic remodeling and neuronal death in the hippocampus and other brain regions.

How can childhood poverty lead to behavioral differences in self-regulation and subsequent psychopathology?

Challenges common to poverty may cause alterations in top-down and/or bottom-up self-regulation behavioral processes. Deficits in self-regulation could lead to an unawareness of one´s own behavior and its consequences, difficulties resolving differences between one´s actual behavior and outcomes, and an inability to detect and anticipate negative outcomes. These challenges may contribute to the development and maintenance of psychopathology.