I am a relative newbie to fMRI analysis so please bear with me on this one!
We have been running blocked design (30sec on and off)language paradigms on
a number of subjects and we want to test laterality. Having already looked
at voxel count measures we want to look at the data from the point of view
of HRF amplitude.
What we want to do is compare the HRF in the left and right hemisphere and
derive laterality measures from this and compare these to our voxel measures.
Firstly is it possible to derive HRF amplitudes using FSL? If so how do I do
Secondly, I assume that I should use the first level analysis as a mask for
the HRF measurements. However, on some subjects there were no active voxels
in one hemisphere with z set to > 3.5. I assume for this part of the study I
could reduce z so that all the subjects had active voxels in both
hemispheres, however, would I be correct in saying that this would reduce
the overall quality of the HRF's measured?
Any help would be greatly appreciated.