The final outputs from DR are a "randomise" step. So see the
respective online manual (randomise command) for the files you get.
You can tweak the script, so that the final randomise yields different
outputs (eg, TFCE corrected, cluster mass, cluster extent and so on).
Cheers,
Cornelius
On Fri, Jan 14, 2011 at 11:18 AM, Christian F. Beckmann
<[log in to unmask]> wrote:
> Hi
>
>> I have 3 subjects, each scanned twice, under two different conditions, 3D and 2D, where subjects passively viewed a 3D video clip and a 2D video clip in separate sessions without a model. If I want to compare the two conditions, would I first use melodic concat-ICA and then use dual regression to do this?
>>
>
> Yes, that's one option
>
>> If so, for the melodic inputs, do I set up the 3D group and the 2D group inputs separately, or do I put them all together in the melodic gui setup?
>>
>
> Both is technically possible, though I'd use all data
>
>> When running the dual regression command: dual_regression <group_IC_maps> <des_norm> <design.mat> <design.con> <n_perm> <output_directory> <input1> <input2> <input3>...1. How do I determine the number of permutations?
>
> 1/{numer of perms} is the lowest possible p-value you can assess, i.e. 1/200 = 0.005. I suggest using soemthing like 5000.
>
>
>> 2. How do I set up the design.mat and design.con, if it was a model free design?
>>
>
> These are design matrices for the between-subject/session analysis (for which you have a model) _not_ the within session. In your case this is a paired t-test (3 subjects, scanned twice)
>
>
>> I've test run dual regression just to see what outputs I'd get, but I do not understand what they mean or what to do with the outputs. Is there another step I have to do after running dual regression?
>>
>
> I can't comment on things like 'I've test run dual regression just to see what outputs I'd get' - maybe you have specific questions about specific output files?
>
> hth
> Christian
>
>> Thanks,
>> Amy
>
--
Dr. med. Cornelius J. Werner
Department of Neurology
RWTH Aachen University
Pauwelsstr. 30
52074 Aachen
Germany
Institute of Neuroscience and Medicine
MR Physics - INM4
Research Centre Juelich
52425 Juelich
Germany
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