Dear all, Would it be fine to combine subjects with different slice counts while doing analysis on SPM? Would it cause any issues particularly for the 2nd level analysis? Thanks.

I’m sure this is another “it depends”. The echo time is an important factor not just for coverage, but you can get differences in BOLD response using one versus another. If you use one echo time for one group and a different for another, you won’t be able to tell if the difference came from echo tim…

That depends… [image] Different number of voxels among different subjects in fMRI data I have fMRI BOLD activations for 4 different subjects for different tasks. The problem is that the number of voxels for each subject differs by some amount. The data for the…

For my case, voxel sizes will be the same. I am planning of running either a multiband sequence with additional slices or decrease the TE from 30ms to 25ms on my 32 slice protocol to get a few more slices. If say, I have 30 participants acquired on 32 slices and now start collecting data with more …

For my case this is a within subjects design, but there is a possibility of doing a between-subject comparison as well. So as you said, different TE’s across participants would cause issues. But what I understand is that there shouldn’t be any issues on a within-subject basis as long as I don’t comp…

Combining participants with different slice counts

dglen July 29, 2022, 10:25pm 2

That depends…

For group analysis, different number of slices, but otherwise same voxel resolution may be treated as missing data in programs like 3dLME.