2 between subject variables and their interactions in 3dLME

Hi AFNI expert,

My experiment had two between-subject variable (One is group: IGD and RGU; One is Glu, which is a continuous variable), two covariates (Sex: Male and female; Headmotion(called FD here) ) and used 3dLME to see their interaction (Group by Glu). The model failed (see the message below). I had no idea how to modify it. Besides, Any suggests are welcomed. Thank you so much!

Errors is as follow:

All your explanatory variables are at the between-individuals level. Therefore, 3dLME is not a suitable tool for this case. Use 3dMVM instead. Additionally, if the two groups and two sexes differ in Glu and FD, consider addressing the centering issue.


Thank you so much for your guidance! I will use 3dMVM instead and consider the centering issue.