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.

Prenatal family income, but not parental education, is associated with resting brain activity in 1-month-old infants.

Childhood socioeconomic disadvantage is associated with disparities in development and health, possibly through adaptations in children's brain function. However, it is not clear how early in development such neural adaptations might emerge. This study examined whether prenatal family socioeconomic status, operationalized as family income and average years of parental education, prospectively predicts individual differences in infant resting electroencephalography (EEG; theta, alpha, beta, and gamma power) at approximately 1 month of age (N = 160). Infants of mothers reporting lower family income showed more lower-frequency (theta) and less higher-frequency (beta and gamma) power. These associations held when adjusting for other prenatal and postnatal experiences, as well as infant demographic and health-related factors. In contrast, parental education was not significantly associated with infant EEG power in any frequency band. These data suggest that lower prenatal family income is associated with developmental differences in brain function that are detectable within the first month of life.

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.

Associations among average parental educational attainment, maternal stress, and infant screen exposure at 6 months of age.

Evidence suggests that increased use of screens early in life may have negative developmental consequences for children. However, little is known concerning parental factors that predict initial screen exposure in infancy. The primary goal of this study was to examine whether parental educational attainment and maternal stress were associated with infant screen exposure by 6 months of age. A diverse sample of mothers (N = 93) was recruited prenatally. In a follow-up visit when the infants were six months of age (N = 82), we examined factors that may be associated with initial infant exposure to screens. First, mothers reported whether they had already exposed their infants to screens. Thereafter, those mothers who reported already having exposed their infants to screens were further queried to determine the extent of infant screen use. Results demonstrated that among infants exposed to screens, mothers reported an average of nearly 3 h of daily screen use. Average parental educational attainment, but not maternal stress, was significantly associated with initial infant exposure. Of those families who endorsed screen exposure by 6 months, 70 % reported a screen in the room where the child sleeps, nearly half reported using screens to help calm the infant, and about a third reported using a screen at least sometimes during meals, when going to sleep, and while waiting. Parental education around infant screen use behaviors may be important to help promote child development and outcomes.

The Neuroscience of Socioeconomic Inequality.

A burgeoning literature has recently begun investigating the links between socioeconomic inequality and the developing brain. This work suggests widespread disparities in both brain structure and function that begin as early as the first year of life. Here we review disparities in neural structure that have been reported in both cortical and subcortical gray matter, as well as in white matter. Disparities in brain function have also been reported, particularly in circuits that support language, memory, executive functioning, and emotion processing. We additionally review recent work investigating the mechanisms that underlie socioeconomic disparities in brain development. Taken together, this work has the potential to identify important targets for intervention in policy and practice.