A functional MRI study of amygdala responses to angry schematic faces in social anxiety disorder.

Neuroimaging studies using angry or contemptuous human facial photographic stimuli have suggested amygdala hyper-responsivity in social anxiety disorder (SAD). We sought to determine if an angry "schematic face" (simple line drawing) would evoke exaggerated amygdalar responses in SAD patients compared with healthy control (HC) subjects. Angry, happy, and neutral schematic faces were overtly presented to matched cohorts of 11 SAD and 11 HC subjects for passive viewing, whereas brain functional magnetic resonance imaging signal was measured at 1.5 Tesla. Voxel-wise analyses were performed using a random effects model in SPM99. Compared with HC subjects, SAD patients exhibited exaggerated responses in the right amygdala for the Angry versus Neutral contrast. The findings of exaggerated amygdala responses to angry schematic faces in SAD converge with results from earlier neuroimaging studies and illustrate the potential utility of schematic faces for probing amygdala function in psychiatric disorders. One prospective advantage of schematic faces is that they may minimize confounds related to gender, age, or race effects. However, extending earlier findings in healthy subjects, schematic faces appear more effective for probing amygdala responses to arousal-based (Angry versus Neutral) as opposed to valence-based (Angry versus Happy) contrasts.