Hi FSL experts,
I have a question on doing second-level analysis with modeling HRF with FIR. We had a block design experiment where in each run we brush the subject's hand for 30 seconds, followed by a 30s's rest, repeating the brush-rest cycle for 4 times. There were 3 runs like this. Since the subject had stroke at somatosensory cortex, which might alter HRF, I modeled HRF with 8 FIR basis functions within a time window of 24 seconds, given 3-second's TR. Given 8 basis functions, there were 8 EVs and 8 contrasts, and a F-test with all the contrasts turned on. For the first-level analysis, I assume I should be looking at zfstats.nii from the F-test. However, I am not sure how to get correct results when combining the 3 runs together.
What I am currently doing is feeding the 24 cope images (3 runs * 8 copes/run) into the higher-level analysis in FSL. In Full Model Setup - EVs, I set 8 EVs. The 3 cope1.nii.gz files from each of the 3 runs correspond to EV1, and the 3 cope2.nii.gz correspond to EV2, and so on. In Contrasts and F-tests, I set 8 contrasts, each with one EV as 1. Finally, I set one F-tests, with all the contrasts turned on. I assume that zfstat1.nii.gz in the gfeat directory is what I should be looking for. But I am really not sure.