Dear SPMers,
I am reposting this question about the "Basis Functions". This is an Option in the fMRI model
specification module. In addition to the canonical HRF with/without time and dispersion
derivatives, there are the options: "Fourier Set" and "Finite Impulse Response"
I am wondering if the canonical HRF is appropriate for a all brain regions and all tasks.
Probably not or maybe. The time and dispersion derivatives only account for small
differences in timing which, as I understand, do not matter much in a 30 sec block design.
So I am wondering if the other Basis Function options do not make an assumption about the
HRF and would allow for differences across brain areas. Where can I learn more about that?
Please advise,
Michael Froelich
University of Alabama
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