All-zero T maps from first-level analysis in SPM

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There are only zero values in my statistical results (T maps) of first-level analysis. I’ve reviewed the beta and contrast maps, and they appear normal.

I’ve re-run all preprocessing steps for this subject, but the all-zero issues persist.

The description in the file header of the spmT files seems unusual:

descrip: 'SPM{T_[0.9]} - contrast 2: effect1'

Is the number 0.9 representing the degrees of freedom for the t-test?

The analysis code for all subjects are the same. And other subjects’ contrast results look fine and even perfect.

Could you experts help me with the all-zero issues?

Thank you very much!

2

Not sure if this is relevant still, but in case someone else comes across this and find my response helpful I’ll post it. The 0.9 represents your effective degrees of freedom and since it is only 0.9 it could make sense that your spmT map is all zero. What is in your design matrix? Perhaps this participant had a lot of movement and therefore most of their volumes have been scrubbed or censored?