Neural Sensitivity to Ambiguous Social Exclusion Reflects Information Processing Bias in Midadolescents With Higher Levels of Aggression.

Aggression is commonly associated with increased experiences of peer rejection and maladaptive social information processing biases throughout development. Little is known about the neural correlates of peer rejection that might underlie social information processing biases, and whether these neural correlates are common or different across early- and mid-adolescents on a continuum of aggression. Using the Cyberball task, we examined mediofrontal theta (4-7 Hz) event-related EEG spectral power during conditions of explicit and ambiguous social exclusion in 117 participants (57 early adolescents, ages 10-12 years, and 60 mid-adolescents, ages 14-16 years). Participants with at least 10 artifact-free trials per condition were included in further EEG analysis. In total, 95 participants (42 early adolescents, 53 mid-adolescents) were included for further analyses of EEG spectral theta power. Results examining moderation effects between aggression level and age groups showed that mid-adolescents, but not early adolescents, with higher levels of aggression displayed enhanced theta power during the early processing (200-400 ms) of ambiguous ("not my turn") exclusion events. The pattern of heightened neural sensitivity to ambiguous exclusion events reflects early detection and inclusion monitoring which might facilitate processing biases that are more prominent among mid-adolescents with higher levels of aggression.