Figure 4.

Three studies provide convergent evidence that facial behavior has structural correlates in the face area of precentral gyrus. Our original and replication samples found total facial behavior correlated with gray matter volume in the precentral gyrus. These clusters both overlapped with an area of the left precentral gyrus in which electrical stimulation elicits facial behavior in humans (Roux et al. 2020). For illustration purposes, the clusters (P < .005, uncorrected) without the T-score color gradient are overlaid on the left precentral gyrus. MRIcroGL was used to overlay the results on the brain, and Affinity Designer was used to refine the final figure.