Are there negative cycles of peer victimization and rejection sensitivity? Testing ri-CLPMs in two longitudinal samples of young adolescents.

This study's aim was to examine whether there are negative increasing cycles of peer victimization and rejection sensitivity over time. Drawing from Social Information Processing Theory, we hypothesized that victimization leads to higher levels of rejection sensitivity, which would put adolescents at risk for higher future victimization. Data were collected in a four-wave study with 233 Dutch adolescents starting secondary education (Mage = 12.7 years), and a three-wave study with 711 Australian adolescents in the last years of primary school (Mage = 10.8 years). Random-intercept cross-lagged panel models were used to disentangle between-person from within-person effects. In each sample, a significant between-person association was found: adolescents with higher levels of victimization as compared to their peers also reported higher levels of rejection sensitivity. At the within-person level, all concurrent associations between individual fluctuations of victimization and rejection sensitivity were significant, but there were no significant cross-lagged effects (except in some sensitivity analyses). These findings demonstrate that victimization and rejection sensitivity are interrelated, but there may not be negative victimization-rejection sensitivity cycles during the early-middle adolescent years. Possibly, cycles establish earlier in life or results are due to shared underlying factors. Further research is needed examining different time lags between assessments, age groups, and contexts.

Connecting the dots: social networks in the classroom and white matter connections in the brain.

BACKGROUND: Peer connections in school classrooms play an important role in social-emotional development and mental health. However, research on the association between children's peer relationships and white matter connections in the brain is scarce. We studied associations between peer relationships in the classroom and white matter structural connectivity in a pediatric population-based sample. METHODS: Bullying and victimization, as well as rejection and acceptance, were assessed in classrooms in 634 children at age 7. White matter microstructure (fractional anisotropy (FA), mean diffusivity (MD)) was measured with diffusion tensor imaging at age 10. We examined global metrics of white matter microstructure and used Tract-Based Spatial Statistics (TBSS) for voxel-wise associations. RESULTS: Peer victimization was associated with higher global FA and lower global MD and peer rejection was associated with lower global MD; however, these associations did not remain after multiple testing correction. Voxel-wise TBSS results for peer victimization and rejection were in line with global metrics both in terms of direction and spatial extent of the associations, with associated voxels (pFWE <.05) observed throughout the brain (including corpus callosum, corona radiata, sagittal stratum and superior longitudinal fasciculi). CONCLUSIONS: Although based only on cross-sectional data, the findings could indicate accelerated white matter microstructure maturation in certain brain areas of children who are victimized or rejected more often. However, repeated measurements are essential to unravel this complex interplay of peer connections, maturation and brain development over time.

Parental Support and Positive Mood Buffer Adolescents' Academic Motivation During the COVID-19 Pandemic.

School closures during the first COVID-19 lockdown in 2020 severely disrupted adolescents' lives. We used a daily diary method for 20 days, including online and physical school days, assessing daily mood, social support and conflict, and academic motivation in 102 adolescents aged 12-16 years. We found that adolescents' academic motivation was lower on online compared with physical school days. In general, positive mood was positively associated with academic motivation, and friend conflict related negatively to academic motivation. Moreover, lower levels of parental support were related to lower academic motivation on online versus physical school days. Overall, these findings identified some critical changes in adolescents' daily experiences during the COVID-19 school closure and social-emotional factors that may buffer decreases in adolescents' academic motivation.

I am happy for us: Neural processing of vicarious joy when winning for parents versus strangers.

This study investigated the neural processes underlying vicarious joy and their dependence on emotional closeness. Prior studies revealed that the nucleus accumbens (NAcc) is a target brain region for processing rewards for self, but the neural mechanisms of processing rewards for others are not yet well understood. A functional magnetic resonance imaging (fMRI) paradigm was employed in young adults (N = 30), in combination with a self-report questionnaire on the perceived emotional closeness to the target. We examined the neural correlates of vicarious rewards when winning money for oneself or one of three other targets. To examine family relationships, two of the targets were the mother and father of the participants, and the third target was an unknown stranger. We found an increase in activation in the NAcc when playing for family members compared with a stranger. We further observed a difference in neural activation when winning for the father compared with the mother in an extended network involving the medial prefrontal cortex and precuneus, brain regions involved in mentalizing. These findings were not related to reports of emotional closeness. This new paradigm has considerable value for future research into the fundamental neural processes underlying empathy and vicarious joy.

Developmental Changes and Individual Differences in Trust and Reciprocity in Adolescence.

A Trust Game was used to examine trust and reciprocity development in 12-18-year-old-adolescents (N = 496), as findings have been conflicting and transitions in adolescence remain elusive. Furthermore, this study tested the roles of gender, risk, and individual differences in empathy, impulsivity, and antisocial tendencies in trust and reciprocity. Results indicate stability in trust and a decrease in reciprocity across adolescence, but also show that trust and reciprocity choices were influenced by risk, and that empathy mediated the age-related decrease in reciprocity. Males trusted more than females, but there were no gender differences in reciprocity. These findings highlight the importance of considering individual differences and adolescents' sensitivities to varying contexts in explaining trust and reciprocity development in adolescence.

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.

Development of the Cerebral Cortex across Adolescence: A Multisample Study of Inter-Related Longitudinal Changes in Cortical Volume, Surface Area, and Thickness.

Before we can assess and interpret how developmental changes in human brain structure relate to cognition, affect, and motivation, and how these processes are perturbed in clinical or at-risk populations, we must first precisely understand typical brain development and how changes in different structural components relate to each other. We conducted a multisample magnetic resonance imaging study to investigate the development of cortical volume, surface area, and thickness, as well as their inter-relationships, from late childhood to early adulthood (7-29 years) using four separate longitudinal samples including 388 participants and 854 total scans. These independent datasets were processed and quality-controlled using the same methods, but analyzed separately to study the replicability of the results across sample and image-acquisition characteristics. The results consistently showed widespread and regionally variable nonlinear decreases in cortical volume and thickness and comparably smaller steady decreases in surface area. Further, the dominant contributor to cortical volume reductions during adolescence was thinning. Finally, complex regional and topological patterns of associations between changes in surface area and thickness were observed. Positive relationships were seen in sulcal regions in prefrontal and temporal cortices, while negative relationships were seen mainly in gyral regions in more posterior cortices. Collectively, these results help resolve previous inconsistencies regarding the structural development of the cerebral cortex from childhood to adulthood, and provide novel insight into how changes in the different dimensions of the cortex in this period of life are inter-related.SIGNIFICANCE STATEMENT Different measures of brain anatomy develop differently across adolescence. Their precise trajectories and how they relate to each other throughout development are important to know if we are to fully understand both typical development and disorders involving aberrant brain development. However, our understanding of such trajectories and relationships is still incomplete. To provide accurate characterizations of how different measures of cortical structure develop, we performed an MRI investigation across four independent datasets. The most profound anatomical change in the cortex during adolescence was thinning, with the largest decreases observed in the parietal lobe. There were complex regional patterns of associations between changes in surface area and thickness, with positive relationships seen in sulcal regions in prefrontal and temporal cortices, and negative relationships seen mainly in gyral regions in more posterior cortices.

Friend versus foe: Neural correlates of prosocial decisions for liked and disliked peers.

Although the majority of our social interactions are with people we know, few studies have investigated the neural correlates of sharing valuable resources with familiar others. Using an ecologically valid research paradigm, this functional magnetic resonance imaging study examined the neural correlates of prosocial and selfish behavior in interactions with real-life friends and disliked peers in young adults. Participants (N = 27) distributed coins between themselves and another person, where they could make selfish choices that maximized their own gains or prosocial choices that maximized outcomes of the other. Participants were more prosocial toward friends and more selfish toward disliked peers. Individual prosociality levels toward friends were associated negatively with supplementary motor area and anterior insula activity. Further preliminary analyses showed that prosocial decisions involving friends were associated with heightened activity in the bilateral posterior temporoparietal junction, and selfish decisions involving disliked peers were associated with heightened superior temporal sulcus activity, which are brain regions consistently shown to be involved in mentalizing and perspective taking in prior studies. Further, activation of the putamen was observed during prosocial choices involving friends and selfish choices involving disliked peers. These findings provide insights into the modulation of neural processes that underlie prosocial behavior as a function of a positive or negative relationship with the interaction partner.

Longitudinal links between childhood peer acceptance and the neural correlates of sharing.

Childhood peer acceptance is associated with high levels of prosocial behavior and advanced perspective taking skills. Yet, the neurobiological mechanisms underlying these associations have not been studied. This functional magnetic resonance imaging study examined the neural correlates of sharing decisions in a group of adolescents who had a stable accepted status (n = 27) and a group who had a chronic rejected status (n = 19) across six elementary school grades. Both groups of adolescents played three allocation games in which they could share money with strangers with varying costs and profits to them and the other person. Stably accepted adolescents were more likely to share their money with unknown others than chronically rejected adolescents when sharing was not costly. Neuroimaging analyses showed that stably accepted adolescents, compared to chronically rejected adolescents, exhibited higher levels of activation in the temporo-parietal junction, posterior superior temporal sulcus, temporal pole, pre-supplementary motor area, and anterior insula during costly sharing decisions. These findings demonstrate that stable peer acceptance across childhood is associated with heightened activity in brain regions previously linked to perspective taking and the detection of social norm violations during adolescence, and thereby provide insight into processes underlying the widely established links between peer acceptance and prosocial behavior.

Contributions of Reward Sensitivity to Ventral Striatum Activity Across Adolescence and Early Adulthood.

It was examined how ventral striatum responses to rewards develop across adolescence and early adulthood and how individual differences in state- and trait-level reward sensitivity are related to these changes. Participants (aged 8-29 years) were tested across three waves separated by 2 years (693 functional MRI scans) in an accelerated longitudinal design. The results confirmed an adolescent peak in reward-related ventral striatum, specifically nucleus accumbens, activity. In early to mid-adolescence, increases in reward activation were related to trait-level reward drive. In mid-adolescence to early adulthood decreases in reward activation were related to decreases in state-level hedonic reward pleasure. This study demonstrates that state- and trait-level reward sensitivity account for reward-related ventral striatum activity in different phases of adolescence and early adulthood.

Structural brain development between childhood and adulthood: Convergence across four longitudinal samples.

Longitudinal studies including brain measures acquired through magnetic resonance imaging (MRI) have enabled population models of human brain development, crucial for our understanding of typical development as well as neurodevelopmental disorders. Brain development in the first two decades generally involves early cortical grey matter volume (CGMV) increases followed by decreases, and monotonic increases in cerebral white matter volume (CWMV). However, inconsistencies regarding the precise developmental trajectories call into question the comparability of samples. This issue can be addressed by conducting a comprehensive study across multiple datasets from diverse populations. Here, we present replicable models for gross structural brain development between childhood and adulthood (ages 8-30years) by repeating analyses in four separate longitudinal samples (391 participants; 852 scans). In addition, we address how accounting for global measures of cranial/brain size affect these developmental trajectories. First, we found evidence for continued development of both intracranial volume (ICV) and whole brain volume (WBV) through adolescence, albeit following distinct trajectories. Second, our results indicate that CGMV is at its highest in childhood, decreasing steadily through the second decade with deceleration in the third decade, while CWMV increases until mid-to-late adolescence before decelerating. Importantly, we show that accounting for cranial/brain size affects models of regional brain development, particularly with respect to sex differences. Our results increase confidence in our knowledge of the pattern of brain changes during adolescence, reduce concerns about discrepancies across samples, and suggest some best practices for statistical control of cranial volume and brain size in future studies.

Development of equity preferences in boys and girls across adolescence.

The aim of the current study was to examine the development of equity preferences across adolescence, for boys and girls separately. Participants from 8 to 18 years old (M = 14.09 years; N = 1,216) played four economic allocation games. Analyses revealed a decrease in equity preferences with age and this decrease was stronger for boys than for girls. There was also an age-related increase in the preference for efficient outcomes (i.e., maximization of total available resources), which was again stronger for boys than for girls. Overall, although equity remains as a strong social norm, adolescents are decreasingly strict in adhering to the equity norm and show increasing flexibility in equity preferences.

Gambling for self, friends, and antagonists: differential contributions of affective and social brain regions on adolescent reward processing.

Adolescence is a time of increasing emotional arousal, sensation-seeking and risk-taking, especially in the context of peers. Recent neuroscientific studies have pinpointed to the role of the ventral striatum as a brain region which is particularly sensitive to reward, and to 'social brain' regions, such as the medial prefrontal cortex (mPFC), the precuneus, and the temporal parietal junction, as being particularly responsive to social contexts. However, no study to date has examined adolescents' sensitivity to reward across different social contexts. In this study we examined 249 participants between the ages 8 and 25, on a monetary reward-processing task. Participants could win or lose money for themselves, their best friend and a disliked peer. Winning for self resulted in a mid- to late adolescent specific peak in neural activation in the ventral striatum, whereas winning for a disliked peer resulted in a mid- to late adolescent specific peak in the mPFC. Our findings reveal that ventral striatum and mPFC hypersensitivity in adolescence is dependent on social context. Taken together, these results suggest that increased risk-taking and sensation seeking observed in adolescence might not be purely related to hyperactivity of the ventral striatum, but that these behaviors are probably strongly related to the social context in which they occur.

Behavior and neural correlates of empathy in adolescents.

This study examined neural correlates of empathy in adolescence while observing harmful acts. A total of 32 participants (aged 12-19 years) viewed pictures depicting negative (offenders inflicting intentional harm) and positive (friends socializing) social situations. After viewing each picture, participants could allocate hypothetical points to either the offender or the victim in a dictator game. Behaviorally, participants of all ages acted prosocially towards victims, fairly towards positive individuals and punishingly towards offenders. Brain imaging analyses showed that viewing negative situations was associated with more activation in the bilateral intraparietal lobule and the superior temporal sulcus (STS), whereas viewing positive situations was associated with more medial prefrontal cortex and left temporal parietal junction activity. Analyses testing for associations between brain activity and self-reported empathy showed that the STS was correlated negatively with reports of understanding others' distress and the willingness to help others. Together, the findings suggest that adolescents show similar prosocial behavior, as previously reported in adults with greater STS activity, when observing negative social acts that is modulated by an individual's empathy for others.

Here Comes Revenge: Peer Victimization Relates to Neural and Behavioral Responses to Social Exclusion.

The aim of this study was to examine whether repeated victimization relates to differential processing of social exclusion experiences. It was hypothesized that experiences of repeated victimization would modulate neural processing of social exclusion in the insula, anterior cingulate cortex, and lateral prefrontal cortex. Furthermore, we hypothesized that repeated victimization relates positively to intentions to punish excluders. Exploratively, associations between neural processing and intentions to punish others were examined. The sample consisted of children with known victimization in the past two years (n = 82 (behavioral) / n = 73 (fMRI), 49.4% girls, Mage = 10.6). The participants played Cyberball, an online ball-tossing game, which was manipulated so that in the first block participants were equally included and in the second block they were excluded from play. Victimization was not related to neural activation during social exclusion, although there were indications that victimization may be related to increased insula activation during explicit exclusion. Behaviorally, repeated victimization was related to more intention to punish excluders. Neural activation during social exclusion did not predict intentions to punish excluders, but results tentatively suggested that increased insula activation during social exclusion may be related to increased intentions to punish. Together, these results provide a replication of earlier Cyberball studies and point toward differential processing of social exclusion by children who are victimized.

Growing Up Together in Society (GUTS): A team science effort to predict societal trajectories in adolescence and young adulthood.

Our society faces a great diversity of opportunities for youth. The 10-year Growing Up Together in Society (GUTS) program has the long-term goal to understand which combination of measures best predict societal trajectories, such as school success, mental health, well-being, and developing a sense of belonging in society. Our leading hypothesis is that self-regulation is key to how adolescents successfully navigate the demands of contemporary society. We aim to test these questions using socio-economic, questionnaire (including experience sampling methods), behavioral, brain (fMRI, sMRI, EEG), hormonal, and genetic measures in four large cohorts including adolescents and young adults. Two cohorts are designed as test and replication cohorts to test the developmental trajectory of self-regulation, including adolescents of different socioeconomic status thereby bridging individual, family, and societal perspectives. The third cohort consists of an entire social network to examine how neural and self-regulatory development influences and is influenced by whom adolescents and young adults choose to interact with. The fourth cohort includes youth with early signs of antisocial and delinquent behavior to understand patterns of societal development in individuals at the extreme ends of self-regulation and societal participation, and examines pathways into and out of delinquency. We will complement the newly collected cohorts with data from existing large-scale population-based and case-control cohorts. The study is embedded in a transdisciplinary approach that engages stakeholders throughout the design stage, with a strong focus on citizen science and youth participation in study design, data collection, and interpretation of results, to ensure optimal translation to youth in society.

Neural processing of observed performance-based errors and rewards in the context of friends and unfamiliar peers across adolescence.

Adolescence is characterized by changes in performance monitoring, whereby action outcomes are monitored to subsequently adapt behavior and optimize performance. Observation of performance-based outcomes (i.e., errors and rewards) received by others forms the basis of observational learning. Adolescence is also a period of increasing importance of peers, especially friends, and observing peers forms a crucial aspect of learning in the social context of the classroom. However, to our knowledge, no developmental fMRI studies have examined the neural mechanisms underlying observed performance monitoring of errors and rewards in the context of peers. The current fMRI study investigated the neural correlates of observing performance-based errors and rewards of peers in adolescents aged 9-16 years (N = 80). In the scanner, participants observed either their best friend or an unfamiliar peer play a shooting game resulting in performance-dependent rewards (based on hits) or losses (based on misses, i. e, errors), where outcomes affected both the player and the observing participant. Findings showed higher activation in the bilateral striatum and bilateral anterior insula when adolescents observed peers (i.e., best friend and unfamiliar peer) receive performance-based rewards compared to losses. This might reflect the heightened salience of observed reward processing in the peer context in adolescence. Our results further revealed lower activation in the left temporoparietal junction (TPJ) while adolescents observed the performance-based outcomes (rewards and losses) for their best friend than for an unfamiliar peer. Considering that observation of others' performance-based errors and rewards forms the basis of observational learning, this study provides a crucial first step in understanding and potentially improving adolescent observational learning in the peer context.

Do My Reactions Outweigh My Actions? The Relation between Reactive and Proactive Aggression with Peer Acceptance in Preschoolers.

Aggressive behaviors negatively impact peer relations starting from an early age. However, not all aggressive acts have the same underlying motivations. Reactive aggression arises as a response to an antecedent behavior of someone else, whereas proactive aggression is initiated by the aggressor and is instrumental. In this study, we aim to understand the relation between reactive and proactive aggression and peer acceptance in preschoolers. Parents of 110 children aged between 3 and 6 years old rated their children's manifestation of reactive and proactive aggressive behaviors. To assess the children's peer acceptance score within their class, they completed a paired comparisons task. The outcomes confirmed that reactive aggression in particular is negatively related to peer acceptance at the preschool age. Our results provide insights for the needs and directions of future research and interventions.

Social exclusion and punishment of excluders: neural correlates and developmental trajectories.

Social exclusion is a distressing experience and can result in a reduction of prosocial behavior. In this fMRI study we examined the neural networks involved in social exclusion and subsequent fairness considerations across adolescent development. Participants from 3 age groups (10-12, 14-16 and 19-21 year olds) participated in the study and performed two tasks; first, participants played Cyberball to induce feelings of social inclusion and exclusion, followed by a Dictator game in which participants were asked to divide coins between themselves and the players who previously included or excluded them. Results revealed a network of regions associated with social exclusion, which involve the medial prefrontal cortex (mPFC)/ventral anterior cingulate cortex (vACC), subgenual ACC and the lateral PFC, as well as the insula and the dorsal ACC. Although social exclusion generated strong distress for all age groups, 10-12 year olds showed increased activity in the subgenual ACC in the exclusion game, which has been associated in previous studies with negative affective processing. Results of the Dictator game revealed that all age groups selectively punished the excluders by making lower offers. These offers were associated with activation in the temporoparietal junction (TPJ), superior temporal sulcus (STS) and the lateral PFC. Age comparisons revealed that adults showed additional activity in the insula and dorsal ACC when making offers to the excluders. The results are discussed in the light of recent findings on neural networks involved in social exclusion and the development of social brain regions.

Brain Responses to Peer Feedback in Social Media Are Modulated by Valence in Late Adolescence.

Previous studies have examined the neural correlates of receiving negative feedback from peers during virtual social interaction in young people. However, there is a lack of studies applying platforms adolescents use in daily life. In the present study, 92 late-adolescent participants performed a task that involved receiving positive and negative feedback to their opinions from peers in a Facebook-like platform, while brain activity was measured using functional magnetic resonance imaging (fMRI). Peer feedback was shown to activate clusters in the ventrolateral prefrontal cortex (VLPFC), medial prefrontal cortex (MPFC), superior temporal gyrus and sulcus (STG/STS), and occipital cortex (OC). Negative feedback was related to greater activity in the VLPFC, MPFC, and anterior insula than positive feedback, replicating previous findings on peer feedback and social rejection. Real-life habits of social media use did not correlate with brain responses to negative feedback.