Hello FSL listers,
I'm trying to run a lower-level state-item analysis. In these analyses, you include both
blocked and event-related regressors simultaneously in your model. One constraint is that
your event-related regressors need to be modeled with an FIR basis set and your blocked
regressors need to be modeled with an assumed response shape such as the double-
gamma (c.f. Visscher et al. 2003 for the rationale behind these constraints). The
contrasts will compare the event-related EVs to other event-related EVs, and the blocked
EVs to other blocked EVs.
However, when I try to set up the EVs in the full model setup, I get the following error: In
order to setup contrasts in "Original EVs" mode whilst using basis functions or sinusoidal
harmonics, all the original EVs must be the same basic shape and generate the same
number of real EVs. Please change the EV setup.
If I attempt to create the model using Real EVs, the GUI becomes quickly overwhelmed
(i.e., unusable / freezes) trying to create a matrix of (9 event-related EVs x 9 FIRs) +
three blocked EVs. Even if it didn't freeze, it's just a pain to set up that many contrasts
rather than just using Original EVs.
Is there a way to force feat_gui to allow me to use different basis functions for the
different EVs, as long as I contrast only EVs that have the same basis functions?
Otherwise, is there a relatively easy way to combine two separate design.fsf's into one
design.fsf that will solve for the blocked and event-related Evs simultaneously?
Thanks,
--Greg
____________________________________________________________________
Greg Burgess, Ph.D.
Research Associate, Institute of Cognitive Science
University of Colorado - Boulder
Email: [log in to unmask]
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