Functional brain activation to emotional and nonemotional faces in healthy children: evidence for developmentally undifferentiated amygdala function during the school-age period.

The amygdala is a key region in emotion processing. In particular, fMRI studies have demonstrated that the amygdala is active during the viewing of emotional faces. Previous research has consistently found greater amygdala responses to fearful than to neutral faces in adults, convergent with a focus in the animal literature on the amygdala's role in fear processing. Studies have shown that the amygdala also responds differentially to other facial emotion types in adults. Yet the literature regarding when this differential amygdala responsivity develops is limited and mixed. Thus, the goal of the present study was to examine amygdala responses to emotional and neutral faces in a relatively large sample of healthy school-age children (N = 52). Although the amygdala was active in response to emotional and neutral faces, the results did not support the hypothesis that the amygdala responds differentially to emotional faces in 7- to 12-year-old children. Nonetheless, amygdala activity was correlated with the severity of subclinical depression symptoms and with emotional regulation skills. Additionally, sex differences were observed in frontal, temporal, and visual regions, as well as effects of pubertal development in visual regions. These findings suggest important differences in amygdala reactivity in childhood.