Right amygdala activity tracks BTX-induced corrugator/procerus paralysis. (A) Statistical map (coronal plane, Y = 3, p <0.01, k = 7 voxels) depicting the right amygdala (MNI 21, 3, -24; t(36) = 3.28, p < 0.05 corrected, cluster size = 432 mm3) that corresponded to the effects of BTX. (B) Bar graph showing right amygdala activity to angry vs. happy faces, showing a distinctive quadratic pattern of activity (parameter estimates for angry vs. happy faces were calculated by subtracting happy vs. baseline from angry vs. baseline). Red lines indicate right amygdala activity to angry faces vs. baseline, and blue lines indicate right amygdala activity to happy faces. Error bars indicate standard error of the mean.