Hi Christian,
thanks for the hint. What I did not quite get is why I should run DR
on patients before denoising them? My understanding was that in order
to remove subject-specific noise, I should use fsl_regfilt on each of
the subjects (patients/controls) based on the individual ICA. Or is
there a way to denoise a tcICA melodic_IC using DR that I did not
quite grasp? Thanks for any clarification!
Cheers,
Cornelius
On Sun, Oct 9, 2011 at 11:53 PM, Christian F. Beckmann
<[log in to unmask]> wrote:
> Hi Cornelius,
>
> Subject specific artefacts are not well dealt with by any of the goup ICA approaches based on concatenation (though watch this space ;). The way to do what you want is to run gICA on the patients, run dual regression on the patients and use fsl_regfilt on the patients to denoise these. You cna do the same in the ctrls for the artefacts you fond there. Finally, you'd run dual regression on both groups (against e.g. the group maps from the ctrl group).
>
> hth
> Christian
>
>
>
> On 8 Oct 2011, at 22:16, Cornelius Werner wrote:
>
>> Hi,
>>
>> it has been suggested on the list to generate a set of RSNs from the
>> "healthy" population and to run it against the "patient" group when
>> large differences are expected. That's what I am trying to do because
>> I have reason to assume so.
>> I imagine this means running tcICA on both the control and the patient
>> group separately and then (when calling the dual_regression script)
>> using melodic_IC.nii.gz from the control.gica on the .filelist from
>> the patient.gica - is that right? But how can I include possible
>> additional/specific artefacts represented in the patient
>> melodic_IC.nii.gz that might not necessarily be present or identical
>> in the control group in the analysis? Fslmerge the ICAs of interest
>> from the control melodic_IC into the patient melodic_IC and use that
>> instead (and possibly throw out ICAs from the patient melodic_IC that
>> look similar beforehand)? Did anyone do this succesfully and can
>> advise?
>> Thanks a lot,
>> Cornelius
>>
>> --
>> Dr. med. Cornelius J. Werner
>> Department of Neurology
>> RWTH Aachen University
>> Pauwelsstr. 30
>> 52074 Aachen
>> Germany
>
--
Dr. med. Cornelius J. Werner
Department of Neurology
RWTH Aachen University
Pauwelsstr. 30
52074 Aachen
Germany
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