Craig Peters

Mindfulness and dynamic functional neural connectivity in children and adolescents

BACKGROUND Interventions that promote mindfulness consistently show salutary effects on cognition and emotional wellbeing in adults, and more recently, in children and adolescents. However, we lack understanding of the neurobiological mechanisms underlying mindfulness in youth that should allow for more judicious application of these interventions in clinical and educational settings. METHODS Using multi-echo multi-band fMRI, we examined dynamic (i.e., time-varying) and conventional static resting-state connectivity between core neurocognitive networks (i.e., salience/emotion, default mode, central executive) in 42 children and adolescents (ages 6-17). RESULTS We found that trait mindfulness in youth relates to dynamic but not static resting-state connectivity. Specifically, more mindful youth transitioned more between brain states over the course of the scan, spent overall less time in a certain connectivity state, and showed a state-specific reduction in connectivity between salience/emotion and central executive networks. The number of state transitions mediated the link between higher mindfulness and lower anxiety, providing new insights into potential neural mechanisms underlying benefits of mindfulness on psychological health in youth. CONCLUSIONS Our results provide new evidence that mindfulness in youth relates to functional neural dynamics and interactions between neurocognitive networks, over time.

Community and household-level socioeconomic disadvantage and functional organization of the salience and emotion network in children and adolescents

&NA; Socioeconomic disadvantage (SED) during childhood has been linked to disparities in physical and mental health. A growing body of research has focused on identifying neurodevelopmental consequences of SED, commonly measured using within‐household factors (e.g., household income), to better understand the processes underlying SED‐related disparities. These studies suggest that childhood SED has a widespread impact on brain development, altering development of multiple brain regions simultaneously. These findings also raise the possibility that childhood SED impacts development of key brain systems, such as the salience and emotion network (SEN), which is positioned at the intersection of brain systems involved in cognitive and emotion‐related functioning and is thought to mediate information flow within and between these networks. The present study tests for associations between household‐ and community‐level SED, as well as their interaction, and measures of SEN‐based functional neural organization in 57 children and adolescents (ages 6–17). We applied graph theoretical analyses to resting‐state functional magnetic resonance imaging (fMRI) data to examine SEN‐based functional network topology. Results showed that youth residing in more distressed communities demonstrate lower hub‐like properties (i.e., less efficient global information transfer and fewer connections) of two core SEN nodes – the anterior cingulate cortex and the left supramarginal gyrus. Similarly, lower household income was associated with lower efficiency of the anterior cingulate, but had no effect on the supramarginal gyrus. There was, however, an interaction between income and community SED in the rostral prefrontal cortex, such that higher income was associated with higher clustering coefficient and lower betweenness centrality, suggesting greater local processing and lower influence of this region on information flow across the network. These effects were significant only among youth living in low (but not high) SED communities, suggesting that within‐household SED factors may not protect against the detrimental effects of a disadvantaged community context. Similarly, the age‐related increase in average path length of the left rostral prefrontal cortex was only significant among youth living in low (but not high) SED communities. Given that maturation of the SEN is considered to be a critical functional backbone supporting the development of more flexible cognitive and emotional processes into adulthood, we tested for links between SEN graph metrics and measures of cognitive and emotion‐related functioning. We found that higher community SED and lower income were both associated with lower IQ. Lower IQ, in turn, was associated with global efficiency of the left supramarginal gyrus. Observed effects of SED on SEN‐based functional neural organization may help to explain the strong and pervasive link between childhood SED and disparities in cognitive and emotional outcomes. HighlightsChildhood socioeconomic disadvantage (SED) is linked to a range of poor outcomesNeuroimaging studies suggest that childhood SED has widespread impact on the brainMost studies have examined household SED (e.g., income) but not community SEDCommunity SED had unique effects on the salience and emotion brain networkSED‐related changes in the brain were also associated with lower IQ

Poor between-session recall of extinction learning and hippocampal activation and connectivity in children

Background: In healthy adults, successful between‐session recall of extinction learning depends on the hippocampus and ventromedial prefrontal cortex (vmPFC), especially when tested in the extinction context. Poor extinction recall and dysfunction within hippocampal‐vmPFC circuitry are associated with fear‐based disorders (e.g., anxiety, posttraumatic stress disorder). Despite the early age of onset of virtually all fear‐based disorders and the protracted development of the hippocampus and vmPFC across the first two decades of life, little is known about extinction recall and the underlying neural correlates in children. Methods: Here, we tested extinction recall in 43 pre‐adolescent children (ages 6–11 yrs) by coupling functional magnetic resonance imaging and virtual reality with a novel interpersonal threat‐related two‐day (ABBA) fear‐extinction paradigm. Conditioned fear responding was assessed at behavioral, subjective, physiological, and neural levels. Results: Although children demonstrated intact within‐session extinction, there was poor between‐session recall of extinction learning (retention index: 13.56%), evidenced by elevations in skin conductance, avoidant behavioral responses, and subjective ratings. Elevations in conditioning fear responding were accompanied by activation in the hippocampus and insula, and increased connectivity of the hippocampus with the insula and dorsal anterior cingulate cortex ‐ regions implicated in the return of fear in adult studies. Children who kept more distance from the extinguished cue during extinction subsequently demonstrated heightened hippocampal‐cingulate coupling during recall, suggesting that avoidant behavior interferes with extinction retention. Conclusions: Poor extinction recall in children may have implications for developmental vulnerability to fear‐based disorders, and for the application of therapeutic strategies that rely on principles of extinction (e.g., exposure therapy) to pediatric samples.

Distinct neural correlates of trait resilience within core neurocognitive networks in at-risk children and adolescents

Background Most children who are exposed to threat-related adversity (e.g., violence, abuse, neglect) are resilient - that is, they show stable trajectories of healthy psychological development. Despite this, most research on neurodevelopmental changes following adversity has focused on the neural correlates of negative outcomes, such as psychopathology. The neural correlates of trait resilience in pediatric populations are unknown, and it is unclear whether they are distinct from those related to adversity exposure and the absence of negative outcomes (e.g., depressive symptomology). Methods This functional magnetic resonance imaging (fMRI) study reports on a diverse sample of 55 children and adolescents (ages 6–17 years) recruited from a range of stressful environments (e.g., lower income, threat-related adversity exposure). Participants completed a multi-echo multi-band resting-state fMRI scan and self-report measures of trait resilience and emotion-related symptomology (e.g., depressive symptoms). Resting-state data were submitted to an independent component analysis (ICA) to identify core neurocognitive networks (salience and emotion network [SEN], default mode network [DMN], central executive network [CEN]). We tested for links among trait resilience and dynamic (i.e., time-varying) as well as conventional static (i.e., averaged across the entire session) resting-state functional connectivity (rsFC) of core neurocognitive networks. Results Youth with higher trait resilience spent a lower fraction of time in a particular dynamic rsFC state, characterized by heightened rsFC between the anterior DMN and right CEN. Within this state, trait resilience was associated with lower rsFC of the SEN with the right CEN and anterior DMN. There were no associations among trait resilience and conventional static rsFC. Importantly, although more resilient youth reported lower depressive symptoms, the effects of resilience on rsFC were independent of depressive symptoms and adversity exposure. Conclusions The present study is the first to report on the neural correlates of trait resilience in youth, and offers initial insight into potential adaptive patterns of brain organization in the context of environmental stressors. Understanding the neural dynamics underlying positive adaptation to early adversity will aid in the development of interventions that focus on strengthening resilience rather than mitigating already-present psychological problems.