I have found an interesting issue while using gPPI in SPM12 (v6225).
I've definded the new (gPPI) model, which seems to be ok.
I have also defined contrasts, which also look reasonable in SPM, but the files are like:
con_PPI_Neutral_minus_Punishment_gppi_GNG03.img and con_PPI_Punishment_minus_Neutral_gppi_GNG03.img (where Neutral and Punishment are my conditions and GNG03 is a subject's code),
However there are no .hdr files, and SPM is unable to calculate second level.
Surprisingly, when I rerun the gPPI script, new additional contrast are generated (con_0003.nii and con_0004.nii, which looks also reasonable - so I am going to use them for second level).
Maybe even more surprisngly, when I rerun the script again and again, new contrast are being added, and every second time it is .img (whith descriptive name and no .hdr), and every other second time this are typical con_00XX.nii files.
I hope to deal with it for now with additional con*.nii files, but would be grateful for a hint if and how I could get con*.nii files without need to rerun the script.
Best regards
Marek

edit:
I've just noticed, that while estimating the model and contrasts an error ocurs:
Valid Contrast
Valid Contrast
contrast image 1 : ...written con_0001.nii
spm{T} image 1 : ...written spmT_0001.nii
contrast image 2 : ...written con_0002.nii
spm{T} image 2 : ...written spmT_0002.nii
Moving Contrast Images
error moving contrast PPI_Punishment_minus_Neutral
error moving contrast PPI_Punishment_minus_Neutral
Moving Contrast Images
error moving contrast PPI_Neutral_minus_Punishment
error moving contrast PPI_Neutral_minus_Punishment