Question about ANOVA analysis

Dear Yan,

   I have performed ANOVA  anayalsis of ALFF among PD depression group (Group 1), PD non-depression group (Group 2) and control group (Group 3). I chose AlpahSim for multiple correction under the voxel p value of 0.001 and cluster p value of 0.05. After ANOVA, I performed post-hoc under the mask file of F.nii other than the Z value abtained by DPABI, for the reason that I wanted to add disease duration as covariates when compared Group 1 and Group 2. Am I right of the method? 

   Using the above method, I found that when comparing to Group 3, both Group 1 and Group 2 had different ALFF value in SMA. However, SMA was not found when performing ANOVA analysis. It seems strange and unreasonable to me. I wonder if I was wrong somehow, or was it just normal?

   Hope for your reply.

  Best!

   Mia  

 

Hi Mia,

1. You can do that.

2. Possibly some SMA voxels are significant in ANOVA, but they can not survive the cluster correction.

Best,

Chao-Gan