Just create a text file (not bfloat) where each row is a different time point. You can have multiple columns and can specify how many of them to use in the analysis.

On 5/18/2021 5:03 PM, Eli Bulger wrote:

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Hello,

I am working with task-based functional data pre-processed with fMRIPrep that I am trying to run through the FSFAST pipeline. I would like to use some of the nuisance regressors / confounds outputted by fMRIPrep as external regressors.

The documentation for "mkanalysis-sess" (shown below) lists this as an option, but I am not sure how to go about creating the .bfloat file(s).

Is there any documentation / example / tool that can provide some guidance on how to do this? Any advice is much appreciated!

"mk-analysis-sess" documentation referred to:

-extreg [extregstem]

external regressor

Use external regressors when doing estimation. The external regressors should be stored in the bfloat "volume" with stem extregstem. There should actually be only one file there (extregstem_000.bfloat). It should have one row, and the number of columns should be equal to the number of external regressors. The number of frames must be equal to the number time points. There should be an external regressor file in each run directory. By default, all the regressors will be used, but this can be changed with -nextreg. See also -mcextreg.

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