the design matrices are treated slightly differently by FIRST compared with FEAT. The main difference is that FIRST does not model separate group variances and so ignores the “Group” column in the Glm gui. Another difference is that only F-tests are needed if you just want to look for any change in vertex position.
嗯嗯，明白了，邮件内容也很详细。但是对于2x2的，有四组，就不太知道怎么设置了
另外对于邮件里的问题，我对native space和MNI space也有点疑问，我能不能这么理解，native space是把所有个体的该结构通过rigid align到同一个位置，计算每个个体该结构顶点投射到mean shape上距离（--useRigidAlign : Uses a 6 Degrees Of Freedom transformation to remove pose from the meshes (see --useScale if you wish to remove size as well). All meshes are aligned to the mean shape from the shape Model 这里的pose我理解的是该结构的三维空间相对位置）；然后MNI空间就是不仅统一了位置，还可能引入一些线性配准过程中来的改变。