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Dichter
BIAC Faculty
190 Posts |
 Posted - Aug 15 2007 : 2:54:40 PM
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| We have a scan with one useable functional run for a particular subject. How would I create a 2nd-level feat folder for that subject? In other words, I have a first-level analysis for the run, but in order to read that subject into a 3rd-level (groupwise) analysis, I need his data in 2nd-level format (with cope directories). I was hoping that indicating "1" for number of analyses would be a work-around, but higher-level analyses require a minimum of 2 lower-level feat directories. Thanks. |
Gabriel S. Dichter, PhD
UNC Departments of Psychiatry & Psychology
http://www.can.unc.edu/ |
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petty
BIAC Staff
USA
453 Posts |
Posted - Aug 15 2007 : 3:34:25 PM
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| in this case a 2nd level would just be a copy of the first level ... i think the best you could do is not point to lower level feat directories, but point the 3rd level all the way down to the .nii.gz for this particular cope. |
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tankersley
BIAC Alum
USA
143 Posts |
Posted - Aug 15 2007 : 3:40:37 PM
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How do I run higher-level FEAT when some inputs are first-level and some are higher-level?
For example, if you have some subjects where you have just a single session, and some where you have a couple, and you want to do a multi-subject higher-level analysis:
Run all first-level FEAT analyses for all sessions and all subjects, including running the normal registration.
For each subject with more than one scan, run a higher-level analysis for that subject's sessions, using fixed-effects stats option if you have just 2 or 3 scans and possibly using mixed-effects FLAME1 if you have several. Use a group-mean model (i.e., single EV, all 1s in that EV and a single contrast with a single 1 in it).
Now do the multi-subject higher-level analysis: Select the "Inputs are 3D cope images" input option. For the single-session subjects, choose the relevant subject.feat/stats/copeN image as input, and for the multi-session FEATs that you have just run, select the relevant subject.gfeat/copeN.feat/stats/cope1 image (note that N will be the same in both cases). The rest of the higher-level settings are as normal.
http://www.fmrib.ox.ac.uk/fslfaq/#feat_mixedup |
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Single run in FSL
