Dear FSL experts,

I used two method to filter my fMRI data.

A. using Feat GUI, click the high-pass filter,

in report.html (autogenerated by feat), the responding code is as follow:

fslmaths prefiltered_func_data_intoform -bptf 33.3333333 -1 -add tempMean prefiltered_func_data_tempfilt

B. using a code:

fslmaths prefiltered_func_data_intoform -bptf 33.3333333 -1 prefiltered_func_data_tempfilt

and then I registered the above two .nii files into MNI template, and had a look on them.

they are so different…… I think the only possible reason is the “-add tempMean” in A method.

why FSL automatically add the tempMean("mean funcdata") in filter stage? method A or B which is better? I will appreciate it if you help me with this question.