Unfortunately, the feat_gui becomes unusable when we switch to Real EVs and try to set
up the model by hand. It seems that there are too many Real EVs (9 FIRs x 9 EVs) for the
GUI to handle. Even using a paste window, it just sits and hangs for nearly an hour.
We've tried this on a Quad-core Mac with 8GB of RAM and an 8-core Mac with 16GB of
RAM, so I don't think that resources are the issue. I'd appreciate any suggestions about
how to make it easier to use different basis sets.
Thanks,
--Greg
On Thu, 21 May 2009 09:12:29 +0100, Steve Smith <[log in to unmask]> wrote:
>Hi - if you want a 'mixed' design in this way I presume that the best
>solution is just to change the setup contrasts option from "Original
>EVs" to "Real EVs" and hand-setup the contrasts for every single basis-
>set EV?
>
>Cheers.
>
>
>On 20 May 2009, at 19:33, Greg Burgess wrote:
>
>> 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]
>>
>
>
>---------------------------------------------------------------------------
>Stephen M. Smith, Professor of Biomedical Engineering
>Associate Director, Oxford University FMRIB Centre
>
>FMRIB, JR Hospital, Headington, Oxford OX3 9DU, UK
>+44 (0) 1865 222726 (fax 222717)
>[log in to unmask] http://www.fmrib.ox.ac.uk/~steve
>---------------------------------------------------------------------------
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