Dear Mark,
great, that's what I figured. Thanks a lot for the quick
response!
Best wishes,
Katharina
On Sat, 15 Mar 2014 09:14:09 +0000
Mark Jenkinson <[log in to unmask]> wrote:
> Dear Katharina,
>
> You don't have to worry about this - the dual regression
>technique takes care of it by performing regressions
>(spatial and then temporal) to estimate the
>subject-specific timecourses and spatial maps, rather
>than simple averages. So it takes into account the sign
>of the connectivities.
>
> All the best,
> Mark
>
>
> On 14 Mar 2014, at 17:46, Katharina Bey
><[log in to unmask]> wrote:
>
>> Dear FSL experts,
>>
>> I ran MELODIC + dual regression to estimate the average
>>time series of each component for each subject (stage 1
>>outputs). I want to use these for further analyses. Now
>>I'm wondering how exactly the individual time series are
>>estimated. Some of my components contain negative as well
>>as positive connections. So if the stage 1 outputs are
>>generated by averaging time series within each component
>>(as I have read in a few papers), won't this lead to
>>faulty results if there are positive and negative
>>connections? I guess that "averaging" might just be wrong
>>terminology here and the negative connections are somehow
>>accounted for. Still, I want to make sure because this
>>might explain some of my results.
>>
>> Thanks a lot for your help!
>>
>> Best,
>> Katharina
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