Hi Takeshi,

I believe that you simple need to change the prefix settings.

Prefix: [1×1 struct] % Left: {'Sn(1) PPI_'}, Right: {'Sn(2) PPI_'}

If this change doesn't work, can you send me your SPM.mat file and the a mat-file version of the parameter structure and I can take a closer look at the issue.

I'm also assuming that your task names are actually Task1 and Task2 or that your actual script replaced these with their actual names. If not, you'll also want to make that change as well.

The key is to get the Prefix setting correct as leaving out PPI_, I think will use the task columns for the contrast.

Best,
Donald