Hi,
Yes I did try the third level analysis and it looks great. The thing that
initially worried me was while looking at the copes that I have passed up to
the higher level feat is that the overlap of the data sets that had
mid-level processing compared to those that didn't is where I see some of
the most significant activation after the higher-level analysis. I was just
worried that this could be caused by the differences of the data sets.
My hope is that the registration happens first in Feat and the ones without
mid-level processing are transformed to match the ones with mid-level
processing, but I'm not sure if there is a way for me to know this without
asking.
Either way, I'm looking into the design.fsf file which may have some answers
as well.
Thank you so much for the reply.
-James
On Wed, 24 Feb 2010 18:10:16 +0000, Stephen Smith <[log in to unmask]> wrote:
>Hi - did you try the 3rd level analysis to see if it would work? I'm
>guessing that what's concerning you is that you are looking at some
>first-level COPEs and seeing that they are still in native space; this
>is normal, it is not until you tell FEAT to use these in a higher-
>level analysis that these get resampled into standard space in a
>reg_standard subdirectory.
>
>Cheers.
>
>
>
>On 24 Feb 2010, at 16:37, James Sheehan wrote:
>
>> Hi all,
>>
>> I need to know a bit about how higher level Feat handles mixed cope
>> files.
>>
>> I have a unique data set that is split according to subject generated
>> ratings into 1min data sets (30 seconds before rating, 30 seconds
>> after).
>>
>> It is a graduated rating of 1-4, but subjects were free to rate up
>> or down.
>>
>> I'm interested in the transitions (1 to 2, 2 to 3, 3to4).
>>
>> Some subjects had multiple transitions such as 1 2 3 2 3 (so this
>> has 2
>> ratings of 2 to 3)
>>
>> The data (all data) is fed through FSLwarp using FNIRT transforms to
>> get the
>> data into MNI space.
>>
>> Then I've used Feat to combine repeated ratings per subject using
>> fixed effects.
>>
>> So the issue that I have is that the cope files being passed up to
>> my final
>> processing stage are mixed; some have the mid-level processing and
>> some do
>> not. The cope files with mid-level processing look like they are
>> transformed
>> in some way (I'm guessing to MNI152 1x1x1, but the data without mid-
>> level
>> processing is 2x2x2).
>>
>> I'm worried that this will create false positives in the data
>> because I am
>> unsure of how Feat handles data sets that are mixed in this way. I'm
>> hoping
>> it doesn't matter, but I need to check and then think of how to
>> resolve it.
>>
>> Thanks all,
>>
>> -James
>>
>
>
>---------------------------------------------------------------------------
>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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>
>
>
>
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