Children's shyness and neural responses to social exclusion: Patterns of midfrontal theta power usually not observed until adolescence.

Adverse peer experiences, such as social exclusion, are known risks for socioemotional problems among shy youth. Yet, little is known about how shy children and adolescents process social exclusion in the brain and whether these responses are amplified in adolescence. Using the Cyberball task, we examined mediofrontal theta (4-7 Hz) event-related EEG spectral power during conditions of fair play and social exclusion in 122 participants (58 children, ages 10-12 years, and 64 adolescents, ages 14-17 years). Age effects of the task showed that adolescents displayed heightened theta power to both outright rejection and baseline "not my turn" events, whereas children showed higher theta power to rejection compared with "not my turn" events. Further results on individual differences showed that children with relatively higher levels of shyness displayed enhanced theta power to both rejection and "not my turn" events-a pattern that also was observed in adolescents. These findings suggest that a pattern of heightened neural sensitivity to both outright social exclusion and threats of exclusion, which is the norm by adolescence, also is observed in children with higher levels of shyness. The similar neural response pattern might be driven by salient social motivations that similarly modify the social cognition and behaviors of these groups and might reflect neural antecedents of rejection sensitivity.