Neural Correlates of Social Rejection during Adolescence

Developmental research has demonstrated important consequences of both experiencing and witnessing peer rejection during adolescence; however, the neural mechanisms underlying these experiences are unknown. These studies aimed to extend previous research by examining direct and observed peer rejection among adolescents, using a combination of neuroimaging and behavioral techniques. The goal of study 1 was to establish the neural correlates of adolescents' experiences with peer rejection. Twenty-three adolescents were ostensibly rejected by peers during an functional magnetic resonance imaging (fMRI) scan. Afterwards, participants reported their distress and rejection sensitivity, and parents reported participants' interpersonal competence. Adolescents displayed a unique network of neural regions during peer rejection, and correlations with individual difference measures suggested that individuals who particularly value peer acceptance might be most sensitive to rejection experiences. The goal of study 2 was to test the hypothesis that adolescents' neural activity in the subgenual anterior cingulate cortex (subACC), a region linked with heightened social distress in study 1, was predictive of their risk for future depression. During an fMRI scan, twenty adolescents were ostensibly excluded by peers, and depressive symptoms were assessed via parental reports concurrently and one year later. Findings indicated that subACC activity during exclusion related to increases in depressive symptoms, suggesting that subACC responsivity to peer rejection may be a neural marker of adolescents' risk for depression. The goal of study 3 was to examine the neural correlates of adolescents' 'empathic' processes during observed peer rejection. Twenty adolescents were scanned while they observed an individual being ostensibly excluded by others. They reported their trait empathy, and wrote emails to the excluded victim that were rated by outside observers for their level of prosocial behavior. Results indicated that witnessing peer rejection engaged neural regions related to both mentalizing and affective pain processes, and revealed important links between empathic neural responses, trait empathy, and prosocial behavior. As a whole, these three studies merge the fields of adolescent peer relations and developmental neuroscience, and contribute novel and important insights about adolescents' peer interactions and mental health.