Eye blink rate predicts reward decisions in adolescents

The ventral striatum displays hyper-responsiveness to reward in adolescents relative to other age groups, and animal research on the developmental trajectory of the dopaminergic system suggests that dopamine may underlie adolescent sensitivity to reward. However, practical limitations prevent the direct measurement of dopamine in healthy adolescents. Eye blink rate (EBR) shows promise as a proxy measure of striatal dopamine D2 receptor function. We investigated developmental differences in the relationship between EBR and reward-seeking behavior on a risky decision-making task. Increasing EBR was associated with greater reward maximization on the task for adolescent but not adult participants. Furthermore, adolescents demonstrated greater sensitivity to reward value than adults, as evinced by shifts in decision patterns based on increasing potential reward. These findings suggest that previously observed adolescent behavioral and neural hypersensitivity to reward may in fact be due to greater dopamine receptor activity, as represented by the relationship of blink rate and reward-seeking behavior. They also demonstrate the feasibility and utility of using EBR as a proxy for dopamine in healthy youth in whom direct measurements of dopamine are prohibitively invasive.

Links between parental depression and longitudinal changes in youths' neural sensitivity to rewards

Parental depression is a significant risk factor for adolescents' engagement in risk taking. Yet the neural processes that mediate the link between parental depression and adolescents' functioning remain unknown. Using a longitudinal functional magnetic resonance imaging design, we investigated how parental depression is associated with changes in adolescents' neural reactivity to rewards during a risk-taking task, and how such changes in neural reactivity are associated with changes in risk-taking behavior. Greater parental depressive symptoms were associated with increases in their adolescent child's risk taking and self-reported externalizing behavior over time. At the neural level, adolescents of parents with greater depressive symptoms showed longitudinal increases in the ventral striatum and dorsolateral prefrontal cortex to rewards during risk taking. Longitudinal increases in adolescents' ventral striatum activation mediates the link between greater parental depression and increases in adolescents' risk taking and externalizing behavior. These findings provide novel evidence that parental depression may contribute to changes in adolescents' neural reactivity to rewards over time, which is associated with greater increases in their risk taking and externalizing behavior.

When Is an Adolescent an Adult? Assessing Cognitive Control in Emotional and Nonemotional Contexts

An individual is typically considered an adult at age 18, although the age of adulthood varies for different legal and social policies. A key question is how cognitive capacities relevant to these policies change with development. The current study used an emotional go/no-go paradigm and functional neuroimaging to assess cognitive control under sustained states of negative and positive arousal in a community sample of one hundred ten 13- to 25-year-olds from New York City and Los Angeles. The results showed diminished cognitive performance under brief and prolonged negative emotional arousal in 18- to 21-year-olds relative to adults over 21. This reduction in performance was paralleled by decreased activity in fronto-parietal circuitry, implicated in cognitive control, and increased sustained activity in the ventromedial prefrontal cortex, involved in emotional processes. The findings suggest a developmental shift in cognitive capacity in emotional situations that coincides with dynamic changes in prefrontal circuitry. These findings may inform age-related social policies.

FDA cigarette warning labels lower craving and elicit frontoinsular activation in adolescent smokers

Cigarette smoking is an economically and epidemiologically expensive public health concern. Most adult smokers become addicted during adolescence, rendering it a crucial period for prevention and intervention. Although litigation claims have delayed implementation, graphic warning labels proposed by the U.S. Food and Drug Administration (FDA) may be a promising way to achieve this goal. We aimed to determine the efficacy of the labels in reducing in-scanner craving and to characterize the neurobiological responses in adolescent and adult smokers and non-smokers. While undergoing functional magnetic resonance imaging, thirty-nine 13- to 18-year-old adolescent and forty-one 25- to 30-year-old adult smokers and non-smokers rated their desire to smoke when presented with emotionally graphic warning labels and comparison non-graphic labels. Compared with adult smokers, adolescent smokers exhibited greater craving reduction in response to the warning labels. Although smokers evinced overall blunted recruitment of insula and dorsolateral prefrontal cortex (DLPFC) relative to non-smokers, an effect that was stronger in adolescent smokers, parametrically increasing activation of these regions was associated with greater craving reduction. Functional connectivity analyses suggest that greater DLPFC regulation of limbic regions predicted cigarette craving. These data underscore a prominent role of frontoinsular circuitry in predicting the efficacy of FDA graphic warning labels in craving reduction in adult and adolescent smokers.

School-Based Sex Education and Neuroscience: What We Know About Sex, Romance, Marriage, and Adolescent Brain Development

BACKGROUND

Many school-based abstinence-only sex education curricula state that sexual activity outside of marriage is likely to have harmful psychological effects. Recent advances in neuroscience have expanded our understanding of the neural underpinnings of romantic love, marriage, sexual desire, and sexual behavior and improved our understanding of adolescent brain development.

METHODS

In this article, we review recent advances in neuroscience and clarify what is known about the link between neural development and adolescent romantic and sexual behavior and what opportunities exist for future research.

RESULTS

Whereas the evidence from neuroscience does not yet allow for clear conclusions about the cost or benefits of early romantic relationships and sexual behavior, it does indicate that providing developmentally appropriate education contributes to lifelong sexual health.

CONCLUSIONS

Developing policies and practices for school-based sex education that reflect current research will best support the sexual and reproductive health of adolescents throughout their lives.

Neural mechanisms of social influence in adolescence

During the transformative period of adolescence, social influence plays a prominent role in shaping young people's emerging social identities, and can impact their propensity to engage in prosocial or risky behaviors. In this study, we examine the neural correlates of social influence from both parents and peers, two important sources of influence. Nineteen adolescents (age 16-18 years) completed a social influence task during a functional magnetic resonance imaging (fMRI) scan. Social influence from both sources evoked activity in brain regions implicated in mentalizing (medial prefrontal cortex, left temporoparietal junction, right temporoparietal junction), reward (ventromedial prefrontal cortex), and self-control (right ventrolateral prefrontal cortex). These results suggest that mental state reasoning, social reward and self-control processes may help adolescents to evaluate others' perspectives and overcome the prepotent force of their own antecedent attitudes to shift their attitudes toward those of others. Findings suggest common neural networks involved in social influence from both parents and peers.

The use of functional and effective connectivity techniques to understand the developing brain

Developmental neuroscience, the study of the processes that shape and reshape the maturing brain, is a growing field still in its nascent stages. The developmental application of functional and effective connectivity techniques, which are tools that measure the interactions between elements of the brain, has revealed insight to the developing brain as a complex system. However, this insight is granted in discrete windows of consecutive time. The current review uses dynamic systems theory as a conceptual framework to understand how functional and effective connectivity tools may be used in conjunction to capture the dynamic process of change that occurs with development.

Neural systems underlying reward and approach behaviors in childhood and adolescence

Transitions into and out of adolescence are critical developmental periods of reward-seeking and approach behaviors. Converging evidence suggests that intriguing reward-related behavioral shifts are mediated by developmental changes in frontostriatal circuitry. This chapter explores how the conceptual frameworks and empirical studies in the field of developmental cognitive neuroscience have contributed to understanding reward-related behavior across development.The chapter concludes with some implications for adaptive and maladaptive behaviors that arise from these behaviors as children transition from childhood to adolescence.

Adolescents' emotional competence is associated with parents' neural sensitivity to emotions

An essential component of youths’ successful development is learning to appropriately respond to emotions, including the ability to recognize, identify, and describe one’s feelings. Such emotional competence is thought to arise through the parent–child relationship. Yet, the mechanisms by which parents transmit emotional competence to their children are difficult to measure because they are often implicit, idiosyncratic, and not easily articulated by parents or children. In the current study, we used a multifaceted approach that went beyond self-report measures and examined whether parental neural sensitivity to emotions predicted their child’s emotional competence. Twenty-two adolescent–parent dyads completed an fMRI scan during which they labeled the emotional expressions of negatively valenced faces. Results indicate that parents who recruited the amygdala, VLPFC, and brain regions involved in mentalizing (i.e., inferring others’ emotional states) had adolescent children with greater emotional competence. These results held after controlling for parents’ self-reports of emotional expressivity and adolescents’ self-reports of the warmth and support of their parent relationships. In addition, adolescents recruited neural regions involved in mentalizing during affect labeling, which significantly mediated the associated between parental neural sensitivity and adolescents’ emotional competence, suggesting that youth are modeling or referencing their parents’ emotional profiles, thereby contributing to better emotional competence.

Neural correlates of risky decision making in anxious youth and healthy controls

BACKGROUND

Pediatric anxiety disorders are chronic and impairing conditions that are characterized by risk aversion and avoidance; however, the neural correlates of decision making under risk in anxious youth remain poorly understood.

METHODS

Youth with a primary diagnosis of separation anxiety, social phobia, or generalized anxiety disorder (n = 16) and healthy controls (n = 15), performed a risky decision-making task under conditions of potential gain or loss while undergoing a functional magnetic resonance imaging (fMRI) scan.

RESULTS

Analyses were conducted to examine neural response to risky versus nonrisky choices in each condition. Anxious youth made fewer risky choices during potential loss compared to controls. Both groups elicited strong frontostriatal activation during risky choice. During risky choice in the gain condition, controls exhibited greater activation in ventral putamen during risky choice than during nonrisky choice and than anxious youth. In the loss condition, controls exhibited greater activation in medial prefrontal cortex during risk-taking while anxious youth exhibited greater engagement of amygdala and insula. Neural activation during risky choice was associated with individual differences in anxiety symptom severity, such that as anxiety symptomatology increased, there was decreased recruitment of the ventral striatum in the gain condition and increasing recruitment of the amygdala in the loss condition.

CONCLUSIONS

Youth with anxiety disorders differ from their nonanxious peers on both behavioral and neurobiological indices during risky decision making; these differences are exacerbated by symptom severity and they shed light on the pathophysiology of pediatric anxiety. Neural correlates of risky decision making in anxious youth and healthy controls.

Teens impulsively react rather than retreat from threat

There is a significant inflection in risk taking and criminal behavior during adolescence, but the basis for this increase remains largely unknown. An increased sensitivity to rewards has been suggested to explain these behaviors, yet juvenile offences often occur in emotionally charged situations of negative valence. How behavior is altered by changes in negative emotional processes during adolescence has received less attention than changes in positive emotional processes. The current study uses a measure of impulsivity in combination with cues that signal threat or safety to assess developmental changes in emotional responses to threat cues. We show that adolescents, especially males, impulsively react to threat cues relative to neutral ones more than adults or children, even when instructed not to respond. This adolescent-specific behavioral pattern is paralleled by enhanced activity in limbic cortical regions implicated in the detection and assignment of emotional value to inputs and in the subsequent regulation of responses to them when successfully suppressing impulsive responses to threat cues. In contrast, prefrontal control regions implicated in detecting and resolving competing responses show an adolescent-emergent pattern (i.e. greater activity in adolescents and adults relative to children) during successful suppression of a response regardless of emotion. Our findings suggest that adolescence is a period of heightened sensitivity to social and emotional cues that results in diminished regulation of behavior in their presence.

The quality of adolescents' peer relationships modulates neural sensitivity to risk taking

Adolescents' peer culture plays a key role in the development and maintenance of risk-taking behavior. Despite recent advances in developmental neuroscience suggesting that peers may increase neural sensitivity to rewards, we know relatively little about how the quality of peer relations impact adolescent risk taking. In the current 2-year three-wave longitudinal study, we examined how chronic levels of peer conflict relate to risk taking behaviorally and neurally, and whether this is modified by high-quality peer relationships. Forty-six adolescents completed daily diaries assessing peer conflict across 2 years as well as a measure of peer support. During a functional brain scan, adolescents completed a risk-taking task. Behaviorally, peer conflict was associated with greater risk-taking behavior, especially for adolescents reporting low peer support. High levels of peer support buffered this association. At the neural level, peer conflict was associated with greater activation in the striatum and insula, especially among adolescents reporting low peer support, whereas this association was buffered for adolescents reporting high peer support. Results are consistent with the stress-buffering model of social relationships and underscore the importance of the quality of adolescents' peer relationships for their risk taking.

Neural representation of expected value in the adolescent brain

Previous work shows that the adolescent reward system is hyperactive, but this finding may be confounded by differences in how teens value money. To address this, we examined the neural ontogeny of objective value representation. Adolescent and adult participants performed a monetary gambling task in which they chose to accept or reject gambles of varying expected value. Increasing expected value had a stronger influence over gambling choices in adolescents relative to adults, an effect that was paralleled by greater activation in the ventral striatum in adolescents. This unique adolescent ventral striatum response remained even after matching groups on acceptance behavior. These behavioral and neural data suggest that the value of available options has a greater influence in adolescent versus adult choices, even when objective value and subjective choice are held constant. This research provides further evidence that hyperactivation of reward circuitry in adolescence may be a normative ontogenetic shift that is due to greater valuation in the adolescent brain.

Contextual modulation of medial prefrontal cortex to neutral faces in anxious adolescents

BACKGROUND

Although interpretation biases are well documented among youth with anxiety disorders, understanding of their neural correlates is limited. In particular, there has been little study of how anxious youth neurobiologically represent changing contextual cues that may trigger anxiety. This study examined neural responses during a task in which participants viewed neutral faces paired with experimentally manipulated contextual stimuli.

METHODS

Participants (16 youth with a primary anxiety disorder diagnosis and 15 age- and gender-matched controls) passively viewed neutral faces that were paired with either neutral descriptive vignettes or with vignettes that were potentially anxiety provoking (for example, those that involved performance/social evaluation).

RESULTS

The two groups were differentiated by their medial prefrontal cortex (mPFC) responses, such that context modulated mPFC activation in anxious youth while non-anxious youth demonstrated no such differentiation. Counter to expectations, the performance/evaluation frames were not associated with amygdala reactivity for either group.

CONCLUSIONS

The present investigation is among the first to identify how context modulates mPFC responding to neutral stimuli among anxious youth. It takes an important step toward understanding the neurobiological correlates underlying interpretation biases of neutral stimuli in this population.

Neural mechanisms of impulse control in sexually risky adolescents

The consequences of risky sexual behavior are of public concern. Adolescents contribute disproportionately to negative consequences of risky sexual behavior. However, no research has examined the neural correlates of impulse control and real-world engagement in risky sexual behavior in this population. The aim of the present study was to examine this question. Twenty sexually active adolescents performed an impulse control task during a functional magnetic resonance imaging (fMRI) scan and risky sexual behaviors were assessed through self-report. Sexual riskiness ratings were negatively associated with activation in the prefrontal cortex during response inhibition. These results suggest that diminished engagement of impulse control circuitry may contribute to sexual riskiness in adolescents.

The Teenage Brain

Adolescence is characterized by heightened reward sensitivity. Accumulating evidence suggests that this behavior is associated with neurodevelopmental changes in reward-related neural circuitry. In this article, I review recent studies in animal models and humans that highlight the unique adolescent response to reward in the striatum, a reward-sensitive brain region. This work helps the field understand characteristic adolescent behavior and will be important in addressing policy questions related to this period of development.

The effects of poor quality sleep on brain function and risk taking in adolescence

Insufficient sleep and poor quality sleep are pervasive during adolescence and relate to impairments in cognitive control and increased risk taking. However, the neurobiology underlying the association between sleep and adolescent behavior remains elusive. In the current study, we examine how poor sleep quality relates to cognitive control and reward related brain function during risk taking. Forty-six adolescents participated in a functional magnetic imaging (fMRI) scan during which they completed a cognitive control and risk taking task. Behaviorally, adolescents who reported poorer sleep also exhibited greater risk-taking. This association was paralleled by less recruitment of the dorsolateral prefrontal cortex (DLPFC) during cognitive control, greater insula activation during reward processing, and reduced functional coupling between the DLPFC and affective regions including the insula and ventral striatum during reward processing. Collectively, these results suggest that poor sleep may exaggerate the normative imbalance between affective and cognitive control systems, leading to greater risk-taking in adolescents.

Social cognition in 22q11.2 microdeletion syndrome: relevance to psychosis?

22q11.2 deletion syndrome (22qDS) represents one of the largest known genetic risk factors for schizophrenia. Approximately 30% of individuals with 22qDS develop psychotic illness in adolescence or young adulthood. Given that deficits in social cognition are increasingly viewed as a central aspect of idiopathic schizophrenia, we sought to investigate abilities in this domain as a predictor of psychotic symptoms in 22qDS participants. We assessed multiple domains of social and non-social cognition in 22qDS youth to: 1) characterize performance across these domains in 22qDS, and identify whether 22qDS participants fail to show expected patterns of age-related improvements on these tasks; and 2) determine whether social cognition better predicts positive and negative symptoms than does non-social cognition. Task domains assessed were: emotion recognition and differentiation, Theory of Mind (ToM), verbal knowledge, visuospatial skills, working memory, and processing speed. Positive and negative symptoms were measured using scores obtained from the Structured Interview for Prodromal Symptoms (SIPS). 22qDS participants (N=31, mean age: 15.9) showed the largest impairment, relative to healthy controls (N=31, mean age: 15.6), on measures of ToM and processing speed. In contrast to controls, 22qDS participants did not show age-related improvements on measures of working memory and verbal knowledge. Notably, ToM performance was the best predictor of positive symptoms in 22qDS, accounting for 39% of the variance in symptom severity. Processing speed emerged as the best predictor of negative symptoms, accounting for 37% of the variance in symptoms. Given that ToM was a robust predictor of positive symptoms in our sample, these findings suggest that social cognition may be a valuable intermediate trait for predicting the development of psychosis.

Enhanced striatal sensitivity to aversive reinforcement in adolescents versus adults

Neurodevelopmental changes in mesolimbic regions are associated with adolescent risk-taking behavior. Numerous studies have shown exaggerated activation in the striatum in adolescents compared with children and adults during reward processing. However, striatal sensitivity to aversion remains elusive. Given the important role of the striatum in tracking both appetitive and aversive events, addressing this question is critical to understanding adolescent decision-making, as both positive and negative factors contribute to this behavior. In this study, human adult and adolescent participants performed a task in which they received squirts of appetitive or aversive liquid while undergoing fMRI, a novel approach in human adolescents. Compared with adults, adolescents showed greater behavioral and striatal sensitivity to both appetitive and aversive stimuli, an effect that was exaggerated in response to delivery of the aversive stimulus. Collectively, these findings contribute to understanding how neural responses to positive and negative outcomes differ between adolescents and adults and how they may influence adolescent behavior.

Meaningful family relationships: neurocognitive buffers of adolescent risk taking

Discordant development of brain regions responsible for cognitive control and reward processing may render adolescents susceptible to risk taking. Identifying ways to reduce this neural imbalance during adolescence can have important implications for risk taking and associated health outcomes. Accordingly, we sought to examine how a key family relationship-family obligation-can reduce this vulnerability. Forty-eight adolescents underwent an fMRI scan during which they completed a risk-taking and cognitive control task. Results suggest that adolescents with greater family obligation values show decreased activation in the ventral striatum when receiving monetary rewards and increased dorsolateral PFC activation during behavioral inhibition. Reduced ventral striatum activation correlated with less real-life risk-taking behavior and enhanced dorsolateral PFC activation correlated with better decision-making skills. Thus, family obligation may decrease reward sensitivity and enhance cognitive control, thereby reducing risk-taking behaviors.