Jorien van Hoorn

Neural correlates of prosocial peer influence on public goods game donations during adolescence

A unique feature of adolescent social re-orientation is heightened sensitivity to peer influence when taking risks. However, positive peer influence effects are not yet well understood. The present fMRI study tested a novel hypothesis, by examining neural correlates of prosocial peer influence on donation decisions in adolescence. Participants (age 12-16 years; N = 61) made decisions in anonymous groups about the allocation of tokens between themselves and the group in a public goods game. Two spectator groups of same-age peers-in fact youth actors-were allegedly online during some of the decisions. The task had a within-subjects design with three conditions: (1) EVALUATION: spectators evaluated decisions with likes for large donations to the group, (2) Spectator: spectators were present but no evaluative feedback was displayed and (3) Alone: no spectators nor feedback. Results showed that prosocial behavior increased in the presence of peers, and even more when participants received evaluative feedback from peers. Peer presence resulted in enhanced activity in several social brain regions including medial prefrontal cortex, temporal parietal junction (TPJ), precuneus and superior temporal sulcus. TPJ activity correlated with donations, which suggests similar networks for prosocial behavior and sensitivity to peers. These findings highlight the importance of peers in fostering prosocial development throughout adolescence.

Peer influence effects on risk-taking and prosocial decision-making in adolescence: insights from neuroimaging studies

Peer influence plays a key role in health-compromising risky behaviors during adolescence. However, there is emerging evidence indicating that peer influence can also lead to positive psychosocial outcomes, such as learning, exploration and prosocial behavior. This review highlights the maladaptive and adaptive nature of peer influence and identifies recent functional neuroimaging research investigating the underlying neural mechanisms thereof. In the context of risk-taking, peer effects have been associated with amplified motivational circuitry, including ventral striatum. The social brain (medial prefrontal cortex, temporo-parietal junction and superior temporal sulcus) has been related to peer influence in neutral/prosocial contexts. We propose that peer influence may enhance activation in task-related brain areas; and that the interplay between the motivational circuitry and social brain regions should be investigated to advance our knowledge about the neural underpinnings of peer influence.

Neural Correlates of Social Influence on Risk Taking and Substance Use in Adolescents

Purpose of ReviewAdolescents often engage in elevated levels of risk taking that give rise to substance use. Family and peers constitute the primary contextual risk factors for adolescent substance use. This report reviews how families and peers influence adolescent neurocognitive development to inform their risk taking and subsequent substance use.Recent FindingsDevelopmental neuroscience using functional magnetic resonance imaging (fMRI) has identified regions of the brain involved in social cognition, cognitive control, and reward processing that are integrally linked to social influence on adolescent risk taking. These neural mechanisms play a role in how peer and family influence (e.g., physical presence, relationship quality, rejection) translate into adolescent substance use.SummaryPeers and families can independently, and in tandem, contribute to adolescent substance use, for better or for worse. We propose that future work utilize fMRI to investigate the neural mechanisms involved in different aspects of peer and family influence and how these contexts uniquely and interactively influence adolescent substance use initiation and escalation across development.

Neural correlates of sibling closeness and association with externalizing behavior in adolescence

Abstract Sibling relationships have been linked to adolescent externalizing behaviors, but the neurobiological factors that underlie this association have not been identified. This study investigated sibling closeness and birth order as a predictor of adolescent externalizing behavior via differences in neural processes during safe decision‐making. A total of 77 adolescents (range = 12‐15 years, Mage = 13.45 years, 40 females) completed a computerized driving task during a functional MRI scan. Results showed that adolescents’ perceptions of sibling closeness were associated with greater neural activation in the anterior insula, ventral striatum and left ventrolateral prefrontal cortex when making safe decisions, suggesting that the quality of sibling relationships modulates adolescent neurocognition even without being present. Furthermore, moderated mediation analyses revealed that higher sibling closeness was associated with lower externalizing behavior via left anterior insula activation during safe decision‐making, but only for adolescents without older siblings (i.e. eldest children) compared to adolescents who had multiple older siblings. Importantly, these findings persisted above and beyond parental and peer closeness and sibling characteristics (i.e. sex, relatedness, birth order), highlighting the significant influence of sibling relationships on adolescent externalizing behavior through the brain.

Moderate social sensitivity in a risky context supports adaptive decision making in adolescence: evidence from brain and behavior

Abstract Adolescence is a time of increased social-affective sensitivity, which is often related to heightened health-risk behaviors. However, moderate levels of social sensitivity, relative to either low (social vacuum) or high levels (exceptionally attuned), may confer benefits as it facilitates effective navigation of the social world. The present fMRI study tested a curvilinear relationship between social sensitivity and adaptive decision-making. Participants (ages 12–16; N = 35) played the Social Analogue Risk Task, which measures participants’ willingness to knock on doors in order to earn points. With each knock, the facial expression of the house’s resident shifted from happy to somewhat angrier. If the resident became too angry, the door slammed and participants lost points. Social sensitivity was defined as the extent to which adolescents adjusted their risky choices based on shifting facial expressions. Results confirmed a curvilinear relationship between social sensitivity and self-reported adaptive decision-making at the behavioral and neural level. Moderate adolescent social sensitivity was modulated via heightened tracking of social cues in the temporoparietal junction, insula and dorsolateral prefrontal cortex and related to adaptive decision-making. These findings suggest that social-affective sensitivity may positively impact outcomes in adolescence and have implications for interventions to help adolescents reach mature social goals into adulthood.

Differential effects of parent and peer presence on neural correlates of risk taking in adolescence

Abstract Adolescence is a developmental period associated with increased health‐risk behaviors and unique sensitivity to the input from the social context, paralleled by major changes in the developing brain. Peer presence increases adolescent risk taking, associated with greater reward‐related activity, while parental presence decreases risk taking, associated with decreased reward‐related activity and increased cognitive control. Yet the effects specific to peers and parents are still unknown. The current functional magnetic resonance imaging (fMRI) study compared within‐person peer and parent influences on risky decision‐making during adolescence (ages 12‐15 years; N = 56). Participants completed the Yellow Light Game (YLG), a computerized driving task, during which they could make safe or risky decisions, in the presence of a peer and their parent. Behavioral findings revealed no effects of social context on risk taking. At the neural level, a collection of affective, social and cognitive regions [ventral striatum (VS), temporo‐parietal junction (TPJ), and dorsolateral prefrontal cortex (dlPFC)] was more active during decision‐making with peers than parents. Additionally, functional connectivity analyses showed greater coupling between affective, social and cognitive control regions (VS‐insula, VS‐TPJ) during decision‐making with parents than peers. These findings highlight the complex nature of social influence processes in peer and parent contexts, and contribute to our understanding of the opportunities and vulnerabilities associated with adolescent social sensitivity.

Turning a Blind Eye? Punishment of Friends and Unfamiliar Peers After Observed Exclusion in Adolescence

In order to decrease the occurrence of social exclusion in adolescence, we need to better understand how adolescents perceive and behave toward peers involved in exclusion. We examined the role of friendships in treatment of perpetrators and victims of social exclusion. Eighty‐nine participants (aged 9–16) observed exclusion of an unfamiliar peer (victim) by their best friend and another unfamiliar peer. Subsequently, participants could give up valuable coins to altruistically punish or help peers. Results showed that participants altruistically compensated victims and punished unfamiliar excluders, but refrained from punishing their friends. Our findings show that friendship with excluders modulates altruistic punishment of peers and provide mechanistic insight into how friendships may influence treatment of peers involved in social exclusion during adolescence.