Adolescent-specific patterns of behavior and neural activity during social reinforcement learning

Humans are sophisticated social beings. Social cues from others are exceptionally salient, particularly during adolescence. Understanding how adolescents interpret and learn from variable social signals can provide insight into the observed shift in social sensitivity during this period. The current study tested 120 participants between the ages of 8 and 25 years on a social reinforcement learning task where the probability of receiving positive social feedback was parametrically manipulated. Seventy-eight of these participants completed the task during fMRI scanning. Modeling trial-by-trial learning, children and adults showed higher positive learning rates than adolescents, suggesting that adolescents demonstrated less differentiation in their reaction times for peers who provided more positive feedback. Forming expectations about receiving positive social reinforcement correlated with neural activity within the medial prefrontal cortex and ventral striatum across age. Adolescents, unlike children and adults, showed greater insular activity during positive prediction error learning and increased activity in the supplementary motor cortex and the putamen when receiving positive social feedback regardless of the expected outcome, suggesting that peer approval may motivate adolescents towards action. While different amounts of positive social reinforcement enhanced learning in children and adults, all positive social reinforcement equally motivated adolescents. Together, these findings indicate that sensitivity to peer approval during adolescence goes beyond simple reinforcement theory accounts and suggests possible explanations for how peers may motivate adolescent behavior.Psycholog

Temperamental Sensitivity to the Effects of Parenting in the Development of Child Anxiety

Thesis (Ph.D.)--University of Washington, 2019The role of parenting behaviors, and their moderation by child temperament, in the development of child anxiety were examined using longitudinal data collected from mothers and their children (N=306) across the preschool period (3-5.5 years of age). Using hierarchical linear regression and regions of significance analyses, interactions were tested between affective parenting behaviors (warmth, negative affect), negative psychological control (intrusiveness) and positive behavioral control (scaffolding) and child fearfulness, across both general and novel/uncertain contexts, to gain better specificity in understanding when, and for which children, particular parenting behaviors contribute to continuities or discontinuities in child anxious behaviors. Parental negative affect and intrusiveness were hypothesized to predict higher later anxiety for temperamentally fearful children, whereas parental scaffolding was hypothesized to predict lower later anxiety for those same children. In contrast to hypotheses, parental warmth predicted lower child anxiety overall (main effect), and there was mixed support for interaction effects. As a secondary aim, parallel models predicting child depression symptoms were also conducted for comparison, to address empirically whether different parenting behaviors contribute uniquely to separable aspects of child internalizing problems. Implications for preventive approaches in parenting children at risk for anxiety, and for incorporating more direct parenting instruction in the context of child anxiety treatment, are discussed

Do neural measures of executive function account for income differences in preschool children's effortful control?

Thesis (Master's)--University of Washington, 2013This study examined whether differences in neural processes of executive attention and inhibitory control accounted for income differences observed in performance on behavioral effortful control tasks. We aimed to clarify what specific mechanisms might underlie the link between the context of low income and diminished executive control development in the preschool period. The study utilized a sample of preschool age children (N =117) whose families represented the full range of income, with 32% of families near poverty and another 32% lower income families. Children completed a neuropsychological battery of effortful control tasks, and then completed two executive function measures while EEG was collected. We predicted that differences in ERP (event-related potentials) correlates of the executive function measures would account for income differences observed on the effortful control battery. Performance and ERPs from the executive measures were related to performance on the effortful control battery. Income predicted performance on the effortful control battery, but was not related to ERPs. Potential implications for this lack of association are discussed

Botulinum toxin-induced facial muscle paralysis affects amygdala responses to the perception of emotional expressions: preliminary findings from an A-B-A design

Background: It has long been suggested that feedback signals from facial muscles influence emotional experience. The recent surge in use of botulinum toxin (BTX) to induce temporary muscle paralysis offers a unique opportunity to directly test this “facial feedback hypothesis.” Previous research shows that the lack of facial muscle feedback due to BTX-induced paralysis influences subjective reports of emotional experience, as well as brain activity associated with the imitation of emotional facial expressions. However, it remains to be seen whether facial muscle paralysis affects brain activity, especially the amygdala, which is known to be responsive to the perception of emotion in others. Further, it is unknown whether these neural changes are permanent or whether they revert to their original state after the effects of BTX have subsided. The present study sought to address these questions by using functional magnetic resonance imaging to measure neural responses to angry and happy facial expressions in the presence or absence of facial paralysis. Results: Consistent with previous research, amygdala activity was greater in response to angry compared to happy faces before BTX treatment. As predicted, amygdala activity in response to angry faces was attenuated when the corrugator/procerus muscles were paralyzed via BTX injection but then returned to its original state after the effects of BTX subsided. This preliminary study comprises a small sample size and no placebo condition; however, the A-B-A design affords the present sample to serve as its own control. Conclusions: The current demonstration that amygdala responses to facial expressions were influenced by facial muscle paralysis offers direct neural support for the facial feedback hypothesis. Specifically, the present findings offer preliminary causal evidence that amygdala activity is sensitive to facial feedback during the perception of the facial expressions of others. More broadly, these data confirm the utility of using BTX to address the effect of facial feedback on neural responses associated with the perception, in addition to the experience or expression of emotion

Adolescents let sufficient evidence accumulate before making a decision when large incentives are at stake

Adolescent decision-making has been described as impulsive and suboptimal in the presence of incentives. In this study we examined the neural substrates of adolescent decision-making using a perceptual discrimination task for which small and large rewards were associated with correctly detecting the direction of motion of a cloud of moving dots. Adults showed a reward bias of faster reaction times on trials for which the direction of motion was associated with a large reward. Adolescents, in contrast, were slower to make decisions on trials associated with large rewards. This behavioral pattern in adolescents was paralleled by greater recruitment of fronto-parietal regions important in representing the accumulation of evidence sufficient for selecting one choice over its alternative and the certainty of that choice. The findings suggest that when large incentives are dependent on performance, adolescents may require more evidence to accumulate prior to responding, to be certain to maximize their gains. Adults, in contrast, appear to be quicker in evaluating the evidence for a decision when primed by rewards. Overall these findings suggest that rather than reacting hastily, adolescents can be incentivized to take more time to make decisions when large rewards are at stake.Psycholog

Transitional and translational studies of risk for anxiety

Adolescence reflects a period of increased rates of anxiety, depression, and suicide. Yet most teens emerge from this period with a healthy, positive outcome. In this article, we identify biological factors that may increase risk for some individuals during this developmental period by: (1) examining changes in neural circuitry underlying core phenotypic features of anxiety as healthy individuals transition into and out of adolescence; (2) examining genetic factors that may enhance the risk for psychopathology in one individual over another using translation from mouse models to human neuroimaging and behavior; and (3) examining the effects of early experiences on core phenotypic features of anxiety using human neuroimaging and behavioral approaches. Each of these approaches alone provides only limited information on genetic and environmental influences on complex human behavior across development. Together, they reflect an emerging field of translational developmental neuroscience in forming important bridges between animal models of neurodevelopmental and neuropsychiatric disorders