[nefsmmzb] Spherical harmonics of your face

When people distinguish faces, exactly what parts of the shapes of the face, that is, facial features, are they most sensitive to?

One way to quantify this question is to expand the shape of a face in terms of Legendre spherical harmonics. One can then run experiments tweaking coefficients one at a time. Which coefficients are people sensitive to? Which coefficients show most variance among the population?

Inspired by the EGM96 geoid describing the fine shape of the earth in spherical harmonics.