Momentary Peer Acceptance: An fMRI-EMA Integration Study of Peer Acceptance and Emotions.

In daily life, experiences of peer acceptance play a crucial role in shaping adolescents' emotional functioning, influencing both positive and negative emotional experiences. While prior research has linked general levels of peer acceptance to adolescent emotions using survey and laboratory-based measures, little work has examined momentary associations in naturalistic settings or investigated the neural mechanisms that may moderate these relationships. This study integrates ecological momentary assessment (EMA) and functional Magnetic Resonance Imaging (fMRI) to examine momentary associations of peer acceptance in 72 adolescents (ages 14-17) over 28 days. Results showed that momentary experiences of peer acceptance predicted higher positive emotions and lower negative emotions. Additionally, results revealed that adolescents with lower baseline temporoparietal junction (TPJ) and lower baseline anterior cingulate cortex (ACC) activation showed a stronger momentary association between peer acceptance and positive emotion. Baseline neural activation did not moderate the momentary relationship between peer acceptance and negative emotions. These findings support that momentary experiences of peer acceptance impact adolescents' emotions in moments each day and suggests potential neural moderators for positive emotions. Findings have implications for the development of neuroscience-informed momentary peer interventions for adolescents.