On 10/31/15 12:04 AM, Reza Rajimehr wrote:

Hi,

I have two questions:

1. In an fMRI experiment, we have 64 stimulus conditions and a

baseline condition. All conditions are presented in each run. After running the analysis:

mkanalysis-sess -a category.rh -surface self rh -fsd bold -fwhm 3 -event-related -paradigm paradigm_category.par -nconditions 64 -refeventdur 1 -TR 2 -polyfit 2 -spmhrf 0 -mcextreg -per-run -force

selxavg3-sess -s subj1sess1 -a category.rh

We load beta.nii.gz in Matlab. It has 131546 rows corresponding to the vertices in rh, and 118 columns. The first 64 columns correspond to the stimulus conditions that we have. I guess the next 6 columns correspond to the motion regressors. What are the remaining 48 columns?

There is a nuisance regressor for each run. So the total = 64 + nruns*nnuisance

2. When we run selxavg3-sess with -run-wise:

selxavg3-sess -s subj1sess1 -a category.rh -run-wise

We have a beta.nii.gz file for each run. But this time, each beta.nii.gz file has 70 columns. Why the number of columns here is different from that in the beta file generated without -run-wise?

In this case, 64 come from the task and 6 are nuisance regressors. doug

Thanks for shedding light on this issue!

Reza

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