SPMers,
Christian Buechel's post
http://www.mailbase.ac.uk/lists/spm/1999-07/0154.html
gave a formula for correcting an onset time, to account for SPM allowing a
user-specified choice of which time point to sample regressors (fMRI_T0).
Is this formula still applicable, or has spm99 now do this automatically
with no user input?
Minor related question: is there any reason that fMRI_T (the number of
sample points per TR for e.g. the hrf) should be the same as the number of
slices? E.g., if I have 24 slices and slice-timing correct to the middle
slice, I think it should be OK to use other values of fMRI_T, as long as
fMRI_T0/fMRI_T = 0.5. Is that right?
Best wishes,
Stephen Fromm
NIDCD/NIH
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